fs/ext4/super.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext4/super.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  from
  11  *
  12  *  linux/fs/minix/inode.c
  13  *
  14  *  Copyright (C) 1991, 1992  Linus Torvalds
  15  *
  16  *  Big-endian to little-endian byte-swapping/bitmaps by
  17  *        David S. Miller (davem@caip.rutgers.edu), 1995
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/string.h>
  22 #include <linux/fs.h>
  23 #include <linux/time.h>
  24 #include <linux/vmalloc.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/backing-dev.h>
  29 #include <linux/parser.h>
  30 #include <linux/buffer_head.h>
  31 #include <linux/exportfs.h>
  32 #include <linux/vfs.h>
  33 #include <linux/random.h>
  34 #include <linux/mount.h>
  35 #include <linux/namei.h>
  36 #include <linux/quotaops.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/dax.h>
  42 #include <linux/cleancache.h>
  43 #include <linux/uaccess.h>
  44 #include <linux/iversion.h>
  45 #include <linux/unicode.h>
  46 #include <linux/part_stat.h>
  47 #include <linux/kthread.h>
  48 #include <linux/freezer.h>
  49
  50 #include "ext4.h"
  51 #include "ext4_extents.h"       /* Needed for trace points definition */
  52 #include "ext4_jbd2.h"
  53 #include "xattr.h"
  54 #include "acl.h"
  55 #include "mballoc.h"
  56 #include "fsmap.h"
  57
  58 #define CREATE_TRACE_POINTS
  59 #include <trace/events/ext4.h>
  60
  61 static struct ext4_lazy_init *ext4_li_info;
  62 static struct mutex ext4_li_mtx;
  63 static struct ratelimit_state ext4_mount_msg_ratelimit;
  64
  65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  66                              unsigned long journal_devnum);
  67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  68 static int ext4_commit_super(struct super_block *sb, int sync);
  69 static void ext4_mark_recovery_complete(struct super_block *sb,
  70                                         struct ext4_super_block *es);
  71 static void ext4_clear_journal_err(struct super_block *sb,
  72                                    struct ext4_super_block *es);
  73 static int ext4_sync_fs(struct super_block *sb, int wait);
  74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  76 static int ext4_unfreeze(struct super_block *sb);
  77 static int ext4_freeze(struct super_block *sb);
  78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  79                        const char *dev_name, void *data);
  80 static inline int ext2_feature_set_ok(struct super_block *sb);
  81 static inline int ext3_feature_set_ok(struct super_block *sb);
  82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  83 static void ext4_destroy_lazyinit_thread(void);
  84 static void ext4_unregister_li_request(struct super_block *sb);
  85 static void ext4_clear_request_list(void);
  86 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  87                                             unsigned int journal_inum);
  88
  89 /*
  90  * Lock ordering
  91  *
  92  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  93  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  94  *
  95  * page fault path:
  96  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  97  *   page lock -> i_data_sem (rw)
  98  *
  99  * buffered write path:
 100  * sb_start_write -> i_mutex -> mmap_sem
 101  * sb_start_write -> i_mutex -> transaction start -> page lock ->
 102  *   i_data_sem (rw)
 103  *
 104  * truncate:
 105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
 106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
 107  *   i_data_sem (rw)
 108  *
 109  * direct IO:
 110  * sb_start_write -> i_mutex -> mmap_sem
 111  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
 112  *
 113  * writepages:
 114  * transaction start -> page lock(s) -> i_data_sem (rw)
 115  */
 116
 117 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 118 static struct file_system_type ext2_fs_type = {
 119         .owner          = THIS_MODULE,
 120         .name           = "ext2",
 121         .mount          = ext4_mount,
 122         .kill_sb        = kill_block_super,
 123         .fs_flags       = FS_REQUIRES_DEV,
 124 };
 125 MODULE_ALIAS_FS("ext2");
 126 MODULE_ALIAS("ext2");
 127 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 128 #else
 129 #define IS_EXT2_SB(sb) (0)
 130 #endif
 131
 132
 133 static struct file_system_type ext3_fs_type = {
 134         .owner          = THIS_MODULE,
 135         .name           = "ext3",
 136         .mount          = ext4_mount,
 137         .kill_sb        = kill_block_super,
 138         .fs_flags       = FS_REQUIRES_DEV,
 139 };
 140 MODULE_ALIAS_FS("ext3");
 141 MODULE_ALIAS("ext3");
 142 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 143
 144 /*
 145  * This works like sb_bread() except it uses ERR_PTR for error
 146  * returns.  Currently with sb_bread it's impossible to distinguish
 147  * between ENOMEM and EIO situations (since both result in a NULL
 148  * return.
 149  */
 150 struct buffer_head *
 151 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
 152 {
 153         struct buffer_head *bh = sb_getblk(sb, block);
 154
 155         if (bh == NULL)
 156                 return ERR_PTR(-ENOMEM);
 157         if (ext4_buffer_uptodate(bh))
 158                 return bh;
 159         ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
 160         wait_on_buffer(bh);
 161         if (buffer_uptodate(bh))
 162                 return bh;
 163         put_bh(bh);
 164         return ERR_PTR(-EIO);
 165 }
 166
 167 static int ext4_verify_csum_type(struct super_block *sb,
 168                                  struct ext4_super_block *es)
 169 {
 170         if (!ext4_has_feature_metadata_csum(sb))
 171                 return 1;
 172
 173         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 174 }
 175
 176 static __le32 ext4_superblock_csum(struct super_block *sb,
 177                                    struct ext4_super_block *es)
 178 {
 179         struct ext4_sb_info *sbi = EXT4_SB(sb);
 180         int offset = offsetof(struct ext4_super_block, s_checksum);
 181         __u32 csum;
 182
 183         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 184
 185         return cpu_to_le32(csum);
 186 }
 187
 188 static int ext4_superblock_csum_verify(struct super_block *sb,
 189                                        struct ext4_super_block *es)
 190 {
 191         if (!ext4_has_metadata_csum(sb))
 192                 return 1;
 193
 194         return es->s_checksum == ext4_superblock_csum(sb, es);
 195 }
 196
 197 void ext4_superblock_csum_set(struct super_block *sb)
 198 {
 199         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 200
 201         if (!ext4_has_metadata_csum(sb))
 202                 return;
 203
 204         es->s_checksum = ext4_superblock_csum(sb, es);
 205 }
 206
 207 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 208                                struct ext4_group_desc *bg)
 209 {
 210         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 211                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 212                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 213 }
 214
 215 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 216                                struct ext4_group_desc *bg)
 217 {
 218         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 219                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 220                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 221 }
 222
 223 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 224                               struct ext4_group_desc *bg)
 225 {
 226         return le32_to_cpu(bg->bg_inode_table_lo) |
 227                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 228                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 229 }
 230
 231 __u32 ext4_free_group_clusters(struct super_block *sb,
 232                                struct ext4_group_desc *bg)
 233 {
 234         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 235                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 236                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 237 }
 238
 239 __u32 ext4_free_inodes_count(struct super_block *sb,
 240                               struct ext4_group_desc *bg)
 241 {
 242         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 243                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 244                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 245 }
 246
 247 __u32 ext4_used_dirs_count(struct super_block *sb,
 248                               struct ext4_group_desc *bg)
 249 {
 250         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 251                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 252                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 253 }
 254
 255 __u32 ext4_itable_unused_count(struct super_block *sb,
 256                               struct ext4_group_desc *bg)
 257 {
 258         return le16_to_cpu(bg->bg_itable_unused_lo) |
 259                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 260                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 261 }
 262
 263 void ext4_block_bitmap_set(struct super_block *sb,
 264                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 265 {
 266         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 267         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 268                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 269 }
 270
 271 void ext4_inode_bitmap_set(struct super_block *sb,
 272                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 273 {
 274         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 275         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 276                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 277 }
 278
 279 void ext4_inode_table_set(struct super_block *sb,
 280                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 281 {
 282         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 283         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 284                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 285 }
 286
 287 void ext4_free_group_clusters_set(struct super_block *sb,
 288                                   struct ext4_group_desc *bg, __u32 count)
 289 {
 290         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 291         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 292                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 293 }
 294
 295 void ext4_free_inodes_set(struct super_block *sb,
 296                           struct ext4_group_desc *bg, __u32 count)
 297 {
 298         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 299         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 300                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 301 }
 302
 303 void ext4_used_dirs_set(struct super_block *sb,
 304                           struct ext4_group_desc *bg, __u32 count)
 305 {
 306         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 307         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 308                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 309 }
 310
 311 void ext4_itable_unused_set(struct super_block *sb,
 312                           struct ext4_group_desc *bg, __u32 count)
 313 {
 314         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 315         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 316                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 317 }
 318
 319 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
 320 {
 321         time64_t now = ktime_get_real_seconds();
 322
 323         now = clamp_val(now, 0, (1ull << 40) - 1);
 324
 325         *lo = cpu_to_le32(lower_32_bits(now));
 326         *hi = upper_32_bits(now);
 327 }
 328
 329 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
 330 {
 331         return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
 332 }
 333 #define ext4_update_tstamp(es, tstamp) \
 334         __ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
 335 #define ext4_get_tstamp(es, tstamp) \
 336         __ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
 337
 338 static void __save_error_info(struct super_block *sb, const char *func,
 339                             unsigned int line)
 340 {
 341         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 342
 343         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 344         if (bdev_read_only(sb->s_bdev))
 345                 return;
 346         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 347         ext4_update_tstamp(es, s_last_error_time);
 348         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 349         es->s_last_error_line = cpu_to_le32(line);
 350         if (es->s_last_error_errcode == 0)
 351                 es->s_last_error_errcode = EXT4_ERR_EFSCORRUPTED;
 352         if (!es->s_first_error_time) {
 353                 es->s_first_error_time = es->s_last_error_time;
 354                 es->s_first_error_time_hi = es->s_last_error_time_hi;
 355                 strncpy(es->s_first_error_func, func,
 356                         sizeof(es->s_first_error_func));
 357                 es->s_first_error_line = cpu_to_le32(line);
 358                 es->s_first_error_ino = es->s_last_error_ino;
 359                 es->s_first_error_block = es->s_last_error_block;
 360                 es->s_first_error_errcode = es->s_last_error_errcode;
 361         }
 362         /*
 363          * Start the daily error reporting function if it hasn't been
 364          * started already
 365          */
 366         if (!es->s_error_count)
 367                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 368         le32_add_cpu(&es->s_error_count, 1);
 369 }
 370
 371 static void save_error_info(struct super_block *sb, const char *func,
 372                             unsigned int line)
 373 {
 374         __save_error_info(sb, func, line);
 375         ext4_commit_super(sb, 1);
 376 }
 377
 378 /*
 379  * The del_gendisk() function uninitializes the disk-specific data
 380  * structures, including the bdi structure, without telling anyone
 381  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 382  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 383  * This is a kludge to prevent these oops until we can put in a proper
 384  * hook in del_gendisk() to inform the VFS and file system layers.
 385  */
 386 static int block_device_ejected(struct super_block *sb)
 387 {
 388         struct inode *bd_inode = sb->s_bdev->bd_inode;
 389         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 390
 391         return bdi->dev == NULL;
 392 }
 393
 394 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 395 {
 396         struct super_block              *sb = journal->j_private;
 397         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 398         int                             error = is_journal_aborted(journal);
 399         struct ext4_journal_cb_entry    *jce;
 400
 401         BUG_ON(txn->t_state == T_FINISHED);
 402
 403         ext4_process_freed_data(sb, txn->t_tid);
 404
 405         spin_lock(&sbi->s_md_lock);
 406         while (!list_empty(&txn->t_private_list)) {
 407                 jce = list_entry(txn->t_private_list.next,
 408                                  struct ext4_journal_cb_entry, jce_list);
 409                 list_del_init(&jce->jce_list);
 410                 spin_unlock(&sbi->s_md_lock);
 411                 jce->jce_func(sb, jce, error);
 412                 spin_lock(&sbi->s_md_lock);
 413         }
 414         spin_unlock(&sbi->s_md_lock);
 415 }
 416
 417 static bool system_going_down(void)
 418 {
 419         return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
 420                 || system_state == SYSTEM_RESTART;
 421 }
 422
 423 /* Deal with the reporting of failure conditions on a filesystem such as
 424  * inconsistencies detected or read IO failures.
 425  *
 426  * On ext2, we can store the error state of the filesystem in the
 427  * superblock.  That is not possible on ext4, because we may have other
 428  * write ordering constraints on the superblock which prevent us from
 429  * writing it out straight away; and given that the journal is about to
 430  * be aborted, we can't rely on the current, or future, transactions to
 431  * write out the superblock safely.
 432  *
 433  * We'll just use the jbd2_journal_abort() error code to record an error in
 434  * the journal instead.  On recovery, the journal will complain about
 435  * that error until we've noted it down and cleared it.
 436  */
 437
 438 static void ext4_handle_error(struct super_block *sb)
 439 {
 440         if (test_opt(sb, WARN_ON_ERROR))
 441                 WARN_ON_ONCE(1);
 442
 443         if (sb_rdonly(sb))
 444                 return;
 445
 446         if (!test_opt(sb, ERRORS_CONT)) {
 447                 journal_t *journal = EXT4_SB(sb)->s_journal;
 448
 449                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 450                 if (journal)
 451                         jbd2_journal_abort(journal, -EIO);
 452         }
 453         /*
 454          * We force ERRORS_RO behavior when system is rebooting. Otherwise we
 455          * could panic during 'reboot -f' as the underlying device got already
 456          * disabled.
 457          */
 458         if (test_opt(sb, ERRORS_RO) || system_going_down()) {
 459                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 460                 /*
 461                  * Make sure updated value of ->s_mount_flags will be visible
 462                  * before ->s_flags update
 463                  */
 464                 smp_wmb();
 465                 sb->s_flags |= SB_RDONLY;
 466         } else if (test_opt(sb, ERRORS_PANIC)) {
 467                 if (EXT4_SB(sb)->s_journal &&
 468                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 469                         return;
 470                 panic("EXT4-fs (device %s): panic forced after error\n",
 471                         sb->s_id);
 472         }
 473 }
 474
 475 #define ext4_error_ratelimit(sb)                                        \
 476                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 477                              "EXT4-fs error")
 478
 479 void __ext4_error(struct super_block *sb, const char *function,
 480                   unsigned int line, const char *fmt, ...)
 481 {
 482         struct va_format vaf;
 483         va_list args;
 484
 485         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 486                 return;
 487
 488         trace_ext4_error(sb, function, line);
 489         if (ext4_error_ratelimit(sb)) {
 490                 va_start(args, fmt);
 491                 vaf.fmt = fmt;
 492                 vaf.va = &args;
 493                 printk(KERN_CRIT
 494                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 495                        sb->s_id, function, line, current->comm, &vaf);
 496                 va_end(args);
 497         }
 498         save_error_info(sb, function, line);
 499         ext4_handle_error(sb);
 500 }
 501
 502 void __ext4_error_inode(struct inode *inode, const char *function,
 503                         unsigned int line, ext4_fsblk_t block,
 504                         const char *fmt, ...)
 505 {
 506         va_list args;
 507         struct va_format vaf;
 508         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 509
 510         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 511                 return;
 512
 513         trace_ext4_error(inode->i_sb, function, line);
 514         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 515         es->s_last_error_block = cpu_to_le64(block);
 516         if (ext4_error_ratelimit(inode->i_sb)) {
 517                 va_start(args, fmt);
 518                 vaf.fmt = fmt;
 519                 vaf.va = &args;
 520                 if (block)
 521                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 522                                "inode #%lu: block %llu: comm %s: %pV\n",
 523                                inode->i_sb->s_id, function, line, inode->i_ino,
 524                                block, current->comm, &vaf);
 525                 else
 526                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 527                                "inode #%lu: comm %s: %pV\n",
 528                                inode->i_sb->s_id, function, line, inode->i_ino,
 529                                current->comm, &vaf);
 530                 va_end(args);
 531         }
 532         save_error_info(inode->i_sb, function, line);
 533         ext4_handle_error(inode->i_sb);
 534 }
 535
 536 void __ext4_error_file(struct file *file, const char *function,
 537                        unsigned int line, ext4_fsblk_t block,
 538                        const char *fmt, ...)
 539 {
 540         va_list args;
 541         struct va_format vaf;
 542         struct ext4_super_block *es;
 543         struct inode *inode = file_inode(file);
 544         char pathname[80], *path;
 545
 546         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 547                 return;
 548
 549         trace_ext4_error(inode->i_sb, function, line);
 550         es = EXT4_SB(inode->i_sb)->s_es;
 551         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 552         if (ext4_error_ratelimit(inode->i_sb)) {
 553                 path = file_path(file, pathname, sizeof(pathname));
 554                 if (IS_ERR(path))
 555                         path = "(unknown)";
 556                 va_start(args, fmt);
 557                 vaf.fmt = fmt;
 558                 vaf.va = &args;
 559                 if (block)
 560                         printk(KERN_CRIT
 561                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 562                                "block %llu: comm %s: path %s: %pV\n",
 563                                inode->i_sb->s_id, function, line, inode->i_ino,
 564                                block, current->comm, path, &vaf);
 565                 else
 566                         printk(KERN_CRIT
 567                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 568                                "comm %s: path %s: %pV\n",
 569                                inode->i_sb->s_id, function, line, inode->i_ino,
 570                                current->comm, path, &vaf);
 571                 va_end(args);
 572         }
 573         save_error_info(inode->i_sb, function, line);
 574         ext4_handle_error(inode->i_sb);
 575 }
 576
 577 const char *ext4_decode_error(struct super_block *sb, int errno,
 578                               char nbuf[16])
 579 {
 580         char *errstr = NULL;
 581
 582         switch (errno) {
 583         case -EFSCORRUPTED:
 584                 errstr = "Corrupt filesystem";
 585                 break;
 586         case -EFSBADCRC:
 587                 errstr = "Filesystem failed CRC";
 588                 break;
 589         case -EIO:
 590                 errstr = "IO failure";
 591                 break;
 592         case -ENOMEM:
 593                 errstr = "Out of memory";
 594                 break;
 595         case -EROFS:
 596                 if (!sb || (EXT4_SB(sb)->s_journal &&
 597                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 598                         errstr = "Journal has aborted";
 599                 else
 600                         errstr = "Readonly filesystem";
 601                 break;
 602         default:
 603                 /* If the caller passed in an extra buffer for unknown
 604                  * errors, textualise them now.  Else we just return
 605                  * NULL. */
 606                 if (nbuf) {
 607                         /* Check for truncated error codes... */
 608                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 609                                 errstr = nbuf;
 610                 }
 611                 break;
 612         }
 613
 614         return errstr;
 615 }
 616
 617 void ext4_set_errno(struct super_block *sb, int err)
 618 {
 619         if (err < 0)
 620                 err = -err;
 621
 622         switch (err) {
 623         case EIO:
 624                 err = EXT4_ERR_EIO;
 625                 break;
 626         case ENOMEM:
 627                 err = EXT4_ERR_ENOMEM;
 628                 break;
 629         case EFSBADCRC:
 630                 err = EXT4_ERR_EFSBADCRC;
 631                 break;
 632         case EFSCORRUPTED:
 633                 err = EXT4_ERR_EFSCORRUPTED;
 634                 break;
 635         case ENOSPC:
 636                 err = EXT4_ERR_ENOSPC;
 637                 break;
 638         case ENOKEY:
 639                 err = EXT4_ERR_ENOKEY;
 640                 break;
 641         case EROFS:
 642                 err = EXT4_ERR_EROFS;
 643                 break;
 644         case EFBIG:
 645                 err = EXT4_ERR_EFBIG;
 646                 break;
 647         case EEXIST:
 648                 err = EXT4_ERR_EEXIST;
 649                 break;
 650         case ERANGE:
 651                 err = EXT4_ERR_ERANGE;
 652                 break;
 653         case EOVERFLOW:
 654                 err = EXT4_ERR_EOVERFLOW;
 655                 break;
 656         case EBUSY:
 657                 err = EXT4_ERR_EBUSY;
 658                 break;
 659         case ENOTDIR:
 660                 err = EXT4_ERR_ENOTDIR;
 661                 break;
 662         case ENOTEMPTY:
 663                 err = EXT4_ERR_ENOTEMPTY;
 664                 break;
 665         case ESHUTDOWN:
 666                 err = EXT4_ERR_ESHUTDOWN;
 667                 break;
 668         case EFAULT:
 669                 err = EXT4_ERR_EFAULT;
 670                 break;
 671         default:
 672                 err = EXT4_ERR_UNKNOWN;
 673         }
 674         EXT4_SB(sb)->s_es->s_last_error_errcode = err;
 675 }
 676
 677 /* __ext4_std_error decodes expected errors from journaling functions
 678  * automatically and invokes the appropriate error response.  */
 679
 680 void __ext4_std_error(struct super_block *sb, const char *function,
 681                       unsigned int line, int errno)
 682 {
 683         char nbuf[16];
 684         const char *errstr;
 685
 686         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 687                 return;
 688
 689         /* Special case: if the error is EROFS, and we're not already
 690          * inside a transaction, then there's really no point in logging
 691          * an error. */
 692         if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
 693                 return;
 694
 695         if (ext4_error_ratelimit(sb)) {
 696                 errstr = ext4_decode_error(sb, errno, nbuf);
 697                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 698                        sb->s_id, function, line, errstr);
 699         }
 700
 701         ext4_set_errno(sb, -errno);
 702         save_error_info(sb, function, line);
 703         ext4_handle_error(sb);
 704 }
 705
 706 /*
 707  * ext4_abort is a much stronger failure handler than ext4_error.  The
 708  * abort function may be used to deal with unrecoverable failures such
 709  * as journal IO errors or ENOMEM at a critical moment in log management.
 710  *
 711  * We unconditionally force the filesystem into an ABORT|READONLY state,
 712  * unless the error response on the fs has been set to panic in which
 713  * case we take the easy way out and panic immediately.
 714  */
 715
 716 void __ext4_abort(struct super_block *sb, const char *function,
 717                 unsigned int line, const char *fmt, ...)
 718 {
 719         struct va_format vaf;
 720         va_list args;
 721
 722         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 723                 return;
 724
 725         save_error_info(sb, function, line);
 726         va_start(args, fmt);
 727         vaf.fmt = fmt;
 728         vaf.va = &args;
 729         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 730                sb->s_id, function, line, &vaf);
 731         va_end(args);
 732
 733         if (sb_rdonly(sb) == 0) {
 734                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 735                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 736                 /*
 737                  * Make sure updated value of ->s_mount_flags will be visible
 738                  * before ->s_flags update
 739                  */
 740                 smp_wmb();
 741                 sb->s_flags |= SB_RDONLY;
 742                 if (EXT4_SB(sb)->s_journal)
 743                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 744                 save_error_info(sb, function, line);
 745         }
 746         if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
 747                 if (EXT4_SB(sb)->s_journal &&
 748                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 749                         return;
 750                 panic("EXT4-fs panic from previous error\n");
 751         }
 752 }
 753
 754 void __ext4_msg(struct super_block *sb,
 755                 const char *prefix, const char *fmt, ...)
 756 {
 757         struct va_format vaf;
 758         va_list args;
 759
 760         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 761                 return;
 762
 763         va_start(args, fmt);
 764         vaf.fmt = fmt;
 765         vaf.va = &args;
 766         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 767         va_end(args);
 768 }
 769
 770 #define ext4_warning_ratelimit(sb)                                      \
 771                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 772                              "EXT4-fs warning")
 773
 774 void __ext4_warning(struct super_block *sb, const char *function,
 775                     unsigned int line, const char *fmt, ...)
 776 {
 777         struct va_format vaf;
 778         va_list args;
 779
 780         if (!ext4_warning_ratelimit(sb))
 781                 return;
 782
 783         va_start(args, fmt);
 784         vaf.fmt = fmt;
 785         vaf.va = &args;
 786         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 787                sb->s_id, function, line, &vaf);
 788         va_end(args);
 789 }
 790
 791 void __ext4_warning_inode(const struct inode *inode, const char *function,
 792                           unsigned int line, const char *fmt, ...)
 793 {
 794         struct va_format vaf;
 795         va_list args;
 796
 797         if (!ext4_warning_ratelimit(inode->i_sb))
 798                 return;
 799
 800         va_start(args, fmt);
 801         vaf.fmt = fmt;
 802         vaf.va = &args;
 803         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 804                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 805                function, line, inode->i_ino, current->comm, &vaf);
 806         va_end(args);
 807 }
 808
 809 void __ext4_grp_locked_error(const char *function, unsigned int line,
 810                              struct super_block *sb, ext4_group_t grp,
 811                              unsigned long ino, ext4_fsblk_t block,
 812                              const char *fmt, ...)
 813 __releases(bitlock)
 814 __acquires(bitlock)
 815 {
 816         struct va_format vaf;
 817         va_list args;
 818         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 819
 820         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 821                 return;
 822
 823         trace_ext4_error(sb, function, line);
 824         es->s_last_error_ino = cpu_to_le32(ino);
 825         es->s_last_error_block = cpu_to_le64(block);
 826         __save_error_info(sb, function, line);
 827
 828         if (ext4_error_ratelimit(sb)) {
 829                 va_start(args, fmt);
 830                 vaf.fmt = fmt;
 831                 vaf.va = &args;
 832                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 833                        sb->s_id, function, line, grp);
 834                 if (ino)
 835                         printk(KERN_CONT "inode %lu: ", ino);
 836                 if (block)
 837                         printk(KERN_CONT "block %llu:",
 838                                (unsigned long long) block);
 839                 printk(KERN_CONT "%pV\n", &vaf);
 840                 va_end(args);
 841         }
 842
 843         if (test_opt(sb, WARN_ON_ERROR))
 844                 WARN_ON_ONCE(1);
 845
 846         if (test_opt(sb, ERRORS_CONT)) {
 847                 ext4_commit_super(sb, 0);
 848                 return;
 849         }
 850
 851         ext4_unlock_group(sb, grp);
 852         ext4_commit_super(sb, 1);
 853         ext4_handle_error(sb);
 854         /*
 855          * We only get here in the ERRORS_RO case; relocking the group
 856          * may be dangerous, but nothing bad will happen since the
 857          * filesystem will have already been marked read/only and the
 858          * journal has been aborted.  We return 1 as a hint to callers
 859          * who might what to use the return value from
 860          * ext4_grp_locked_error() to distinguish between the
 861          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 862          * aggressively from the ext4 function in question, with a
 863          * more appropriate error code.
 864          */
 865         ext4_lock_group(sb, grp);
 866         return;
 867 }
 868
 869 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
 870                                      ext4_group_t group,
 871                                      unsigned int flags)
 872 {
 873         struct ext4_sb_info *sbi = EXT4_SB(sb);
 874         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
 875         struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
 876         int ret;
 877
 878         if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
 879                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
 880                                             &grp->bb_state);
 881                 if (!ret)
 882                         percpu_counter_sub(&sbi->s_freeclusters_counter,
 883                                            grp->bb_free);
 884         }
 885
 886         if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
 887                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
 888                                             &grp->bb_state);
 889                 if (!ret && gdp) {
 890                         int count;
 891
 892                         count = ext4_free_inodes_count(sb, gdp);
 893                         percpu_counter_sub(&sbi->s_freeinodes_counter,
 894                                            count);
 895                 }
 896         }
 897 }
 898
 899 void ext4_update_dynamic_rev(struct super_block *sb)
 900 {
 901         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 902
 903         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 904                 return;
 905
 906         ext4_warning(sb,
 907                      "updating to rev %d because of new feature flag, "
 908                      "running e2fsck is recommended",
 909                      EXT4_DYNAMIC_REV);
 910
 911         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 912         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 913         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 914         /* leave es->s_feature_*compat flags alone */
 915         /* es->s_uuid will be set by e2fsck if empty */
 916
 917         /*
 918          * The rest of the superblock fields should be zero, and if not it
 919          * means they are likely already in use, so leave them alone.  We
 920          * can leave it up to e2fsck to clean up any inconsistencies there.
 921          */
 922 }
 923
 924 /*
 925  * Open the external journal device
 926  */
 927 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 928 {
 929         struct block_device *bdev;
 930
 931         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 932         if (IS_ERR(bdev))
 933                 goto fail;
 934         return bdev;
 935
 936 fail:
 937         ext4_msg(sb, KERN_ERR,
 938                  "failed to open journal device unknown-block(%u,%u) %ld",
 939                  MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
 940         return NULL;
 941 }
 942
 943 /*
 944  * Release the journal device
 945  */
 946 static void ext4_blkdev_put(struct block_device *bdev)
 947 {
 948         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 949 }
 950
 951 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 952 {
 953         struct block_device *bdev;
 954         bdev = sbi->journal_bdev;
 955         if (bdev) {
 956                 ext4_blkdev_put(bdev);
 957                 sbi->journal_bdev = NULL;
 958         }
 959 }
 960
 961 static inline struct inode *orphan_list_entry(struct list_head *l)
 962 {
 963         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 964 }
 965
 966 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 967 {
 968         struct list_head *l;
 969
 970         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 971                  le32_to_cpu(sbi->s_es->s_last_orphan));
 972
 973         printk(KERN_ERR "sb_info orphan list:\n");
 974         list_for_each(l, &sbi->s_orphan) {
 975                 struct inode *inode = orphan_list_entry(l);
 976                 printk(KERN_ERR "  "
 977                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 978                        inode->i_sb->s_id, inode->i_ino, inode,
 979                        inode->i_mode, inode->i_nlink,
 980                        NEXT_ORPHAN(inode));
 981         }
 982 }
 983
 984 #ifdef CONFIG_QUOTA
 985 static int ext4_quota_off(struct super_block *sb, int type);
 986
 987 static inline void ext4_quota_off_umount(struct super_block *sb)
 988 {
 989         int type;
 990
 991         /* Use our quota_off function to clear inode flags etc. */
 992         for (type = 0; type < EXT4_MAXQUOTAS; type++)
 993                 ext4_quota_off(sb, type);
 994 }
 995
 996 /*
 997  * This is a helper function which is used in the mount/remount
 998  * codepaths (which holds s_umount) to fetch the quota file name.
 999  */
1000 static inline char *get_qf_name(struct super_block *sb,
1001                                 struct ext4_sb_info *sbi,
1002                                 int type)
1003 {
1004         return rcu_dereference_protected(sbi->s_qf_names[type],
1005                                          lockdep_is_held(&sb->s_umount));
1006 }
1007 #else
1008 static inline void ext4_quota_off_umount(struct super_block *sb)
1009 {
1010 }
1011 #endif
1012
1013 static void ext4_put_super(struct super_block *sb)
1014 {
1015         struct ext4_sb_info *sbi = EXT4_SB(sb);
1016         struct ext4_super_block *es = sbi->s_es;
1017         struct buffer_head **group_desc;
1018         struct flex_groups **flex_groups;
1019         int aborted = 0;
1020         int i, err;
1021
1022         ext4_unregister_li_request(sb);
1023         ext4_quota_off_umount(sb);
1024
1025         destroy_workqueue(sbi->rsv_conversion_wq);
1026
1027         if (sbi->s_journal) {
1028                 aborted = is_journal_aborted(sbi->s_journal);
1029                 err = jbd2_journal_destroy(sbi->s_journal);
1030                 sbi->s_journal = NULL;
1031                 if ((err < 0) && !aborted) {
1032                         ext4_set_errno(sb, -err);
1033                         ext4_abort(sb, "Couldn't clean up the journal");
1034                 }
1035         }
1036
1037         ext4_unregister_sysfs(sb);
1038         ext4_es_unregister_shrinker(sbi);
1039         del_timer_sync(&sbi->s_err_report);
1040         ext4_release_system_zone(sb);
1041         ext4_mb_release(sb);
1042         ext4_ext_release(sb);
1043
1044         if (!sb_rdonly(sb) && !aborted) {
1045                 ext4_clear_feature_journal_needs_recovery(sb);
1046                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1047         }
1048         if (!sb_rdonly(sb))
1049                 ext4_commit_super(sb, 1);
1050
1051         rcu_read_lock();
1052         group_desc = rcu_dereference(sbi->s_group_desc);
1053         for (i = 0; i < sbi->s_gdb_count; i++)
1054                 brelse(group_desc[i]);
1055         kvfree(group_desc);
1056         flex_groups = rcu_dereference(sbi->s_flex_groups);
1057         if (flex_groups) {
1058                 for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1059                         kvfree(flex_groups[i]);
1060                 kvfree(flex_groups);
1061         }
1062         rcu_read_unlock();
1063         percpu_counter_destroy(&sbi->s_freeclusters_counter);
1064         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1065         percpu_counter_destroy(&sbi->s_dirs_counter);
1066         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1067         percpu_free_rwsem(&sbi->s_writepages_rwsem);
1068 #ifdef CONFIG_QUOTA
1069         for (i = 0; i < EXT4_MAXQUOTAS; i++)
1070                 kfree(get_qf_name(sb, sbi, i));
1071 #endif
1072
1073         /* Debugging code just in case the in-memory inode orphan list
1074          * isn't empty.  The on-disk one can be non-empty if we've
1075          * detected an error and taken the fs readonly, but the
1076          * in-memory list had better be clean by this point. */
1077         if (!list_empty(&sbi->s_orphan))
1078                 dump_orphan_list(sb, sbi);
1079         J_ASSERT(list_empty(&sbi->s_orphan));
1080
1081         sync_blockdev(sb->s_bdev);
1082         invalidate_bdev(sb->s_bdev);
1083         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1084                 /*
1085                  * Invalidate the journal device's buffers.  We don't want them
1086                  * floating about in memory - the physical journal device may
1087                  * hotswapped, and it breaks the `ro-after' testing code.
1088                  */
1089                 sync_blockdev(sbi->journal_bdev);
1090                 invalidate_bdev(sbi->journal_bdev);
1091                 ext4_blkdev_remove(sbi);
1092         }
1093
1094         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1095         sbi->s_ea_inode_cache = NULL;
1096
1097         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1098         sbi->s_ea_block_cache = NULL;
1099
1100         if (sbi->s_mmp_tsk)
1101                 kthread_stop(sbi->s_mmp_tsk);
1102         brelse(sbi->s_sbh);
1103         sb->s_fs_info = NULL;
1104         /*
1105          * Now that we are completely done shutting down the
1106          * superblock, we need to actually destroy the kobject.
1107          */
1108         kobject_put(&sbi->s_kobj);
1109         wait_for_completion(&sbi->s_kobj_unregister);
1110         if (sbi->s_chksum_driver)
1111                 crypto_free_shash(sbi->s_chksum_driver);
1112         kfree(sbi->s_blockgroup_lock);
1113         fs_put_dax(sbi->s_daxdev);
1114 #ifdef CONFIG_UNICODE
1115         utf8_unload(sbi->s_encoding);
1116 #endif
1117         kfree(sbi);
1118 }
1119
1120 static struct kmem_cache *ext4_inode_cachep;
1121
1122 /*
1123  * Called inside transaction, so use GFP_NOFS
1124  */
1125 static struct inode *ext4_alloc_inode(struct super_block *sb)
1126 {
1127         struct ext4_inode_info *ei;
1128
1129         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1130         if (!ei)
1131                 return NULL;
1132
1133         inode_set_iversion(&ei->vfs_inode, 1);
1134         spin_lock_init(&ei->i_raw_lock);
1135         INIT_LIST_HEAD(&ei->i_prealloc_list);
1136         spin_lock_init(&ei->i_prealloc_lock);
1137         ext4_es_init_tree(&ei->i_es_tree);
1138         rwlock_init(&ei->i_es_lock);
1139         INIT_LIST_HEAD(&ei->i_es_list);
1140         ei->i_es_all_nr = 0;
1141         ei->i_es_shk_nr = 0;
1142         ei->i_es_shrink_lblk = 0;
1143         ei->i_reserved_data_blocks = 0;
1144         spin_lock_init(&(ei->i_block_reservation_lock));
1145         ext4_init_pending_tree(&ei->i_pending_tree);
1146 #ifdef CONFIG_QUOTA
1147         ei->i_reserved_quota = 0;
1148         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1149 #endif
1150         ei->jinode = NULL;
1151         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1152         spin_lock_init(&ei->i_completed_io_lock);
1153         ei->i_sync_tid = 0;
1154         ei->i_datasync_tid = 0;
1155         atomic_set(&ei->i_unwritten, 0);
1156         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1157         return &ei->vfs_inode;
1158 }
1159
1160 static int ext4_drop_inode(struct inode *inode)
1161 {
1162         int drop = generic_drop_inode(inode);
1163
1164         if (!drop)
1165                 drop = fscrypt_drop_inode(inode);
1166
1167         trace_ext4_drop_inode(inode, drop);
1168         return drop;
1169 }
1170
1171 static void ext4_free_in_core_inode(struct inode *inode)
1172 {
1173         fscrypt_free_inode(inode);
1174         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1175 }
1176
1177 static void ext4_destroy_inode(struct inode *inode)
1178 {
1179         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1180                 ext4_msg(inode->i_sb, KERN_ERR,
1181                          "Inode %lu (%p): orphan list check failed!",
1182                          inode->i_ino, EXT4_I(inode));
1183                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1184                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1185                                 true);
1186                 dump_stack();
1187         }
1188 }
1189
1190 static void init_once(void *foo)
1191 {
1192         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1193
1194         INIT_LIST_HEAD(&ei->i_orphan);
1195         init_rwsem(&ei->xattr_sem);
1196         init_rwsem(&ei->i_data_sem);
1197         init_rwsem(&ei->i_mmap_sem);
1198         inode_init_once(&ei->vfs_inode);
1199 }
1200
1201 static int __init init_inodecache(void)
1202 {
1203         ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1204                                 sizeof(struct ext4_inode_info), 0,
1205                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1206                                         SLAB_ACCOUNT),
1207                                 offsetof(struct ext4_inode_info, i_data),
1208                                 sizeof_field(struct ext4_inode_info, i_data),
1209                                 init_once);
1210         if (ext4_inode_cachep == NULL)
1211                 return -ENOMEM;
1212         return 0;
1213 }
1214
1215 static void destroy_inodecache(void)
1216 {
1217         /*
1218          * Make sure all delayed rcu free inodes are flushed before we
1219          * destroy cache.
1220          */
1221         rcu_barrier();
1222         kmem_cache_destroy(ext4_inode_cachep);
1223 }
1224
1225 void ext4_clear_inode(struct inode *inode)
1226 {
1227         invalidate_inode_buffers(inode);
1228         clear_inode(inode);
1229         ext4_discard_preallocations(inode);
1230         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1231         dquot_drop(inode);
1232         if (EXT4_I(inode)->jinode) {
1233                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1234                                                EXT4_I(inode)->jinode);
1235                 jbd2_free_inode(EXT4_I(inode)->jinode);
1236                 EXT4_I(inode)->jinode = NULL;
1237         }
1238         fscrypt_put_encryption_info(inode);
1239         fsverity_cleanup_inode(inode);
1240 }
1241
1242 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1243                                         u64 ino, u32 generation)
1244 {
1245         struct inode *inode;
1246
1247         /*
1248          * Currently we don't know the generation for parent directory, so
1249          * a generation of 0 means "accept any"
1250          */
1251         inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1252         if (IS_ERR(inode))
1253                 return ERR_CAST(inode);
1254         if (generation && inode->i_generation != generation) {
1255                 iput(inode);
1256                 return ERR_PTR(-ESTALE);
1257         }
1258
1259         return inode;
1260 }
1261
1262 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1263                                         int fh_len, int fh_type)
1264 {
1265         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1266                                     ext4_nfs_get_inode);
1267 }
1268
1269 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1270                                         int fh_len, int fh_type)
1271 {
1272         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1273                                     ext4_nfs_get_inode);
1274 }
1275
1276 static int ext4_nfs_commit_metadata(struct inode *inode)
1277 {
1278         struct writeback_control wbc = {
1279                 .sync_mode = WB_SYNC_ALL
1280         };
1281
1282         trace_ext4_nfs_commit_metadata(inode);
1283         return ext4_write_inode(inode, &wbc);
1284 }
1285
1286 /*
1287  * Try to release metadata pages (indirect blocks, directories) which are
1288  * mapped via the block device.  Since these pages could have journal heads
1289  * which would prevent try_to_free_buffers() from freeing them, we must use
1290  * jbd2 layer's try_to_free_buffers() function to release them.
1291  */
1292 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1293                                  gfp_t wait)
1294 {
1295         journal_t *journal = EXT4_SB(sb)->s_journal;
1296
1297         WARN_ON(PageChecked(page));
1298         if (!page_has_buffers(page))
1299                 return 0;
1300         if (journal)
1301                 return jbd2_journal_try_to_free_buffers(journal, page,
1302                                                 wait & ~__GFP_DIRECT_RECLAIM);
1303         return try_to_free_buffers(page);
1304 }
1305
1306 #ifdef CONFIG_FS_ENCRYPTION
1307 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1308 {
1309         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1310                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1311 }
1312
1313 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1314                                                         void *fs_data)
1315 {
1316         handle_t *handle = fs_data;
1317         int res, res2, credits, retries = 0;
1318
1319         /*
1320          * Encrypting the root directory is not allowed because e2fsck expects
1321          * lost+found to exist and be unencrypted, and encrypting the root
1322          * directory would imply encrypting the lost+found directory as well as
1323          * the filename "lost+found" itself.
1324          */
1325         if (inode->i_ino == EXT4_ROOT_INO)
1326                 return -EPERM;
1327
1328         if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1329                 return -EINVAL;
1330
1331         res = ext4_convert_inline_data(inode);
1332         if (res)
1333                 return res;
1334
1335         /*
1336          * If a journal handle was specified, then the encryption context is
1337          * being set on a new inode via inheritance and is part of a larger
1338          * transaction to create the inode.  Otherwise the encryption context is
1339          * being set on an existing inode in its own transaction.  Only in the
1340          * latter case should the "retry on ENOSPC" logic be used.
1341          */
1342
1343         if (handle) {
1344                 res = ext4_xattr_set_handle(handle, inode,
1345                                             EXT4_XATTR_INDEX_ENCRYPTION,
1346                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1347                                             ctx, len, 0);
1348                 if (!res) {
1349                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1350                         ext4_clear_inode_state(inode,
1351                                         EXT4_STATE_MAY_INLINE_DATA);
1352                         /*
1353                          * Update inode->i_flags - S_ENCRYPTED will be enabled,
1354                          * S_DAX may be disabled
1355                          */
1356                         ext4_set_inode_flags(inode);
1357                 }
1358                 return res;
1359         }
1360
1361         res = dquot_initialize(inode);
1362         if (res)
1363                 return res;
1364 retry:
1365         res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1366                                      &credits);
1367         if (res)
1368                 return res;
1369
1370         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1371         if (IS_ERR(handle))
1372                 return PTR_ERR(handle);
1373
1374         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1375                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1376                                     ctx, len, 0);
1377         if (!res) {
1378                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1379                 /*
1380                  * Update inode->i_flags - S_ENCRYPTED will be enabled,
1381                  * S_DAX may be disabled
1382                  */
1383                 ext4_set_inode_flags(inode);
1384                 res = ext4_mark_inode_dirty(handle, inode);
1385                 if (res)
1386                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1387         }
1388         res2 = ext4_journal_stop(handle);
1389
1390         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1391                 goto retry;
1392         if (!res)
1393                 res = res2;
1394         return res;
1395 }
1396
1397 static bool ext4_dummy_context(struct inode *inode)
1398 {
1399         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1400 }
1401
1402 static bool ext4_has_stable_inodes(struct super_block *sb)
1403 {
1404         return ext4_has_feature_stable_inodes(sb);
1405 }
1406
1407 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1408                                        int *ino_bits_ret, int *lblk_bits_ret)
1409 {
1410         *ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1411         *lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1412 }
1413
1414 static const struct fscrypt_operations ext4_cryptops = {
1415         .key_prefix             = "ext4:",
1416         .get_context            = ext4_get_context,
1417         .set_context            = ext4_set_context,
1418         .dummy_context          = ext4_dummy_context,
1419         .empty_dir              = ext4_empty_dir,
1420         .max_namelen            = EXT4_NAME_LEN,
1421         .has_stable_inodes      = ext4_has_stable_inodes,
1422         .get_ino_and_lblk_bits  = ext4_get_ino_and_lblk_bits,
1423 };
1424 #endif
1425
1426 #ifdef CONFIG_QUOTA
1427 static const char * const quotatypes[] = INITQFNAMES;
1428 #define QTYPE2NAME(t) (quotatypes[t])
1429
1430 static int ext4_write_dquot(struct dquot *dquot);
1431 static int ext4_acquire_dquot(struct dquot *dquot);
1432 static int ext4_release_dquot(struct dquot *dquot);
1433 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1434 static int ext4_write_info(struct super_block *sb, int type);
1435 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1436                          const struct path *path);
1437 static int ext4_quota_on_mount(struct super_block *sb, int type);
1438 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1439                                size_t len, loff_t off);
1440 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1441                                 const char *data, size_t len, loff_t off);
1442 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1443                              unsigned int flags);
1444 static int ext4_enable_quotas(struct super_block *sb);
1445
1446 static struct dquot **ext4_get_dquots(struct inode *inode)
1447 {
1448         return EXT4_I(inode)->i_dquot;
1449 }
1450
1451 static const struct dquot_operations ext4_quota_operations = {
1452         .get_reserved_space     = ext4_get_reserved_space,
1453         .write_dquot            = ext4_write_dquot,
1454         .acquire_dquot          = ext4_acquire_dquot,
1455         .release_dquot          = ext4_release_dquot,
1456         .mark_dirty             = ext4_mark_dquot_dirty,
1457         .write_info             = ext4_write_info,
1458         .alloc_dquot            = dquot_alloc,
1459         .destroy_dquot          = dquot_destroy,
1460         .get_projid             = ext4_get_projid,
1461         .get_inode_usage        = ext4_get_inode_usage,
1462         .get_next_id            = dquot_get_next_id,
1463 };
1464
1465 static const struct quotactl_ops ext4_qctl_operations = {
1466         .quota_on       = ext4_quota_on,
1467         .quota_off      = ext4_quota_off,
1468         .quota_sync     = dquot_quota_sync,
1469         .get_state      = dquot_get_state,
1470         .set_info       = dquot_set_dqinfo,
1471         .get_dqblk      = dquot_get_dqblk,
1472         .set_dqblk      = dquot_set_dqblk,
1473         .get_nextdqblk  = dquot_get_next_dqblk,
1474 };
1475 #endif
1476
1477 static const struct super_operations ext4_sops = {
1478         .alloc_inode    = ext4_alloc_inode,
1479         .free_inode     = ext4_free_in_core_inode,
1480         .destroy_inode  = ext4_destroy_inode,
1481         .write_inode    = ext4_write_inode,
1482         .dirty_inode    = ext4_dirty_inode,
1483         .drop_inode     = ext4_drop_inode,
1484         .evict_inode    = ext4_evict_inode,
1485         .put_super      = ext4_put_super,
1486         .sync_fs        = ext4_sync_fs,
1487         .freeze_fs      = ext4_freeze,
1488         .unfreeze_fs    = ext4_unfreeze,
1489         .statfs         = ext4_statfs,
1490         .remount_fs     = ext4_remount,
1491         .show_options   = ext4_show_options,
1492 #ifdef CONFIG_QUOTA
1493         .quota_read     = ext4_quota_read,
1494         .quota_write    = ext4_quota_write,
1495         .get_dquots     = ext4_get_dquots,
1496 #endif
1497         .bdev_try_to_free_page = bdev_try_to_free_page,
1498 };
1499
1500 static const struct export_operations ext4_export_ops = {
1501         .fh_to_dentry = ext4_fh_to_dentry,
1502         .fh_to_parent = ext4_fh_to_parent,
1503         .get_parent = ext4_get_parent,
1504         .commit_metadata = ext4_nfs_commit_metadata,
1505 };
1506
1507 enum {
1508         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1509         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1510         Opt_nouid32, Opt_debug, Opt_removed,
1511         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1512         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1513         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1514         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1515         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1516         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1517         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1518         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1519         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1520         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1521         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1522         Opt_nowarn_on_error, Opt_mblk_io_submit,
1523         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1524         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1525         Opt_inode_readahead_blks, Opt_journal_ioprio,
1526         Opt_dioread_nolock, Opt_dioread_lock,
1527         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1528         Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1529 };
1530
1531 static const match_table_t tokens = {
1532         {Opt_bsd_df, "bsddf"},
1533         {Opt_minix_df, "minixdf"},
1534         {Opt_grpid, "grpid"},
1535         {Opt_grpid, "bsdgroups"},
1536         {Opt_nogrpid, "nogrpid"},
1537         {Opt_nogrpid, "sysvgroups"},
1538         {Opt_resgid, "resgid=%u"},
1539         {Opt_resuid, "resuid=%u"},
1540         {Opt_sb, "sb=%u"},
1541         {Opt_err_cont, "errors=continue"},
1542         {Opt_err_panic, "errors=panic"},
1543         {Opt_err_ro, "errors=remount-ro"},
1544         {Opt_nouid32, "nouid32"},
1545         {Opt_debug, "debug"},
1546         {Opt_removed, "oldalloc"},
1547         {Opt_removed, "orlov"},
1548         {Opt_user_xattr, "user_xattr"},
1549         {Opt_nouser_xattr, "nouser_xattr"},
1550         {Opt_acl, "acl"},
1551         {Opt_noacl, "noacl"},
1552         {Opt_noload, "norecovery"},
1553         {Opt_noload, "noload"},
1554         {Opt_removed, "nobh"},
1555         {Opt_removed, "bh"},
1556         {Opt_commit, "commit=%u"},
1557         {Opt_min_batch_time, "min_batch_time=%u"},
1558         {Opt_max_batch_time, "max_batch_time=%u"},
1559         {Opt_journal_dev, "journal_dev=%u"},
1560         {Opt_journal_path, "journal_path=%s"},
1561         {Opt_journal_checksum, "journal_checksum"},
1562         {Opt_nojournal_checksum, "nojournal_checksum"},
1563         {Opt_journal_async_commit, "journal_async_commit"},
1564         {Opt_abort, "abort"},
1565         {Opt_data_journal, "data=journal"},
1566         {Opt_data_ordered, "data=ordered"},
1567         {Opt_data_writeback, "data=writeback"},
1568         {Opt_data_err_abort, "data_err=abort"},
1569         {Opt_data_err_ignore, "data_err=ignore"},
1570         {Opt_offusrjquota, "usrjquota="},
1571         {Opt_usrjquota, "usrjquota=%s"},
1572         {Opt_offgrpjquota, "grpjquota="},
1573         {Opt_grpjquota, "grpjquota=%s"},
1574         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1575         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1576         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1577         {Opt_grpquota, "grpquota"},
1578         {Opt_noquota, "noquota"},
1579         {Opt_quota, "quota"},
1580         {Opt_usrquota, "usrquota"},
1581         {Opt_prjquota, "prjquota"},
1582         {Opt_barrier, "barrier=%u"},
1583         {Opt_barrier, "barrier"},
1584         {Opt_nobarrier, "nobarrier"},
1585         {Opt_i_version, "i_version"},
1586         {Opt_dax, "dax"},
1587         {Opt_stripe, "stripe=%u"},
1588         {Opt_delalloc, "delalloc"},
1589         {Opt_warn_on_error, "warn_on_error"},
1590         {Opt_nowarn_on_error, "nowarn_on_error"},
1591         {Opt_lazytime, "lazytime"},
1592         {Opt_nolazytime, "nolazytime"},
1593         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1594         {Opt_nodelalloc, "nodelalloc"},
1595         {Opt_removed, "mblk_io_submit"},
1596         {Opt_removed, "nomblk_io_submit"},
1597         {Opt_block_validity, "block_validity"},
1598         {Opt_noblock_validity, "noblock_validity"},
1599         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1600         {Opt_journal_ioprio, "journal_ioprio=%u"},
1601         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1602         {Opt_auto_da_alloc, "auto_da_alloc"},
1603         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1604         {Opt_dioread_nolock, "dioread_nolock"},
1605         {Opt_dioread_lock, "nodioread_nolock"},
1606         {Opt_dioread_lock, "dioread_lock"},
1607         {Opt_discard, "discard"},
1608         {Opt_nodiscard, "nodiscard"},
1609         {Opt_init_itable, "init_itable=%u"},
1610         {Opt_init_itable, "init_itable"},
1611         {Opt_noinit_itable, "noinit_itable"},
1612         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1613         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1614         {Opt_nombcache, "nombcache"},
1615         {Opt_nombcache, "no_mbcache"},  /* for backward compatibility */
1616         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1617         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1618         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1619         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1620         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1621         {Opt_err, NULL},
1622 };
1623
1624 static ext4_fsblk_t get_sb_block(void **data)
1625 {
1626         ext4_fsblk_t    sb_block;
1627         char            *options = (char *) *data;
1628
1629         if (!options || strncmp(options, "sb=", 3) != 0)
1630                 return 1;       /* Default location */
1631
1632         options += 3;
1633         /* TODO: use simple_strtoll with >32bit ext4 */
1634         sb_block = simple_strtoul(options, &options, 0);
1635         if (*options && *options != ',') {
1636                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1637                        (char *) *data);
1638                 return 1;
1639         }
1640         if (*options == ',')
1641                 options++;
1642         *data = (void *) options;
1643
1644         return sb_block;
1645 }
1646
1647 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1648 static const char deprecated_msg[] =
1649         "Mount option \"%s\" will be removed by %s\n"
1650         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1651
1652 #ifdef CONFIG_QUOTA
1653 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1654 {
1655         struct ext4_sb_info *sbi = EXT4_SB(sb);
1656         char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1657         int ret = -1;
1658
1659         if (sb_any_quota_loaded(sb) && !old_qname) {
1660                 ext4_msg(sb, KERN_ERR,
1661                         "Cannot change journaled "
1662                         "quota options when quota turned on");
1663                 return -1;
1664         }
1665         if (ext4_has_feature_quota(sb)) {
1666                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1667                          "ignored when QUOTA feature is enabled");
1668                 return 1;
1669         }
1670         qname = match_strdup(args);
1671         if (!qname) {
1672                 ext4_msg(sb, KERN_ERR,
1673                         "Not enough memory for storing quotafile name");
1674                 return -1;
1675         }
1676         if (old_qname) {
1677                 if (strcmp(old_qname, qname) == 0)
1678                         ret = 1;
1679                 else
1680                         ext4_msg(sb, KERN_ERR,
1681                                  "%s quota file already specified",
1682                                  QTYPE2NAME(qtype));
1683                 goto errout;
1684         }
1685         if (strchr(qname, '/')) {
1686                 ext4_msg(sb, KERN_ERR,
1687                         "quotafile must be on filesystem root");
1688                 goto errout;
1689         }
1690         rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1691         set_opt(sb, QUOTA);
1692         return 1;
1693 errout:
1694         kfree(qname);
1695         return ret;
1696 }
1697
1698 static int clear_qf_name(struct super_block *sb, int qtype)
1699 {
1700
1701         struct ext4_sb_info *sbi = EXT4_SB(sb);
1702         char *old_qname = get_qf_name(sb, sbi, qtype);
1703
1704         if (sb_any_quota_loaded(sb) && old_qname) {
1705                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1706                         " when quota turned on");
1707                 return -1;
1708         }
1709         rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1710         synchronize_rcu();
1711         kfree(old_qname);
1712         return 1;
1713 }
1714 #endif
1715
1716 #define MOPT_SET        0x0001
1717 #define MOPT_CLEAR      0x0002
1718 #define MOPT_NOSUPPORT  0x0004
1719 #define MOPT_EXPLICIT   0x0008
1720 #define MOPT_CLEAR_ERR  0x0010
1721 #define MOPT_GTE0       0x0020
1722 #ifdef CONFIG_QUOTA
1723 #define MOPT_Q          0
1724 #define MOPT_QFMT       0x0040
1725 #else
1726 #define MOPT_Q          MOPT_NOSUPPORT
1727 #define MOPT_QFMT       MOPT_NOSUPPORT
1728 #endif
1729 #define MOPT_DATAJ      0x0080
1730 #define MOPT_NO_EXT2    0x0100
1731 #define MOPT_NO_EXT3    0x0200
1732 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1733 #define MOPT_STRING     0x0400
1734
1735 static const struct mount_opts {
1736         int     token;
1737         int     mount_opt;
1738         int     flags;
1739 } ext4_mount_opts[] = {
1740         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1741         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1742         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1743         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1744         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1745         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1746         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1747          MOPT_EXT4_ONLY | MOPT_SET},
1748         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1749          MOPT_EXT4_ONLY | MOPT_CLEAR},
1750         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1751         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1752         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1753          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1754         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1755          MOPT_EXT4_ONLY | MOPT_CLEAR},
1756         {Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1757         {Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1758         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1759          MOPT_EXT4_ONLY | MOPT_CLEAR},
1760         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1761          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1762         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1763                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1764          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1765         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1766         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1767         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1768         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1769         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1770          MOPT_NO_EXT2},
1771         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1772          MOPT_NO_EXT2},
1773         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1774         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1775         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1776         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1777         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1778         {Opt_commit, 0, MOPT_GTE0},
1779         {Opt_max_batch_time, 0, MOPT_GTE0},
1780         {Opt_min_batch_time, 0, MOPT_GTE0},
1781         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1782         {Opt_init_itable, 0, MOPT_GTE0},
1783         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1784         {Opt_stripe, 0, MOPT_GTE0},
1785         {Opt_resuid, 0, MOPT_GTE0},
1786         {Opt_resgid, 0, MOPT_GTE0},
1787         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1788         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1789         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1790         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1791         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1792         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1793          MOPT_NO_EXT2 | MOPT_DATAJ},
1794         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1795         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1796 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1797         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1798         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1799 #else
1800         {Opt_acl, 0, MOPT_NOSUPPORT},
1801         {Opt_noacl, 0, MOPT_NOSUPPORT},
1802 #endif
1803         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1804         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1805         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1806         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1807         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1808                                                         MOPT_SET | MOPT_Q},
1809         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1810                                                         MOPT_SET | MOPT_Q},
1811         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1812                                                         MOPT_SET | MOPT_Q},
1813         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1814                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1815                                                         MOPT_CLEAR | MOPT_Q},
1816         {Opt_usrjquota, 0, MOPT_Q},
1817         {Opt_grpjquota, 0, MOPT_Q},
1818         {Opt_offusrjquota, 0, MOPT_Q},
1819         {Opt_offgrpjquota, 0, MOPT_Q},
1820         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1821         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1822         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1823         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1824         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1825         {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1826         {Opt_err, 0, 0}
1827 };
1828
1829 #ifdef CONFIG_UNICODE
1830 static const struct ext4_sb_encodings {
1831         __u16 magic;
1832         char *name;
1833         char *version;
1834 } ext4_sb_encoding_map[] = {
1835         {EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1836 };
1837
1838 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1839                                  const struct ext4_sb_encodings **encoding,
1840                                  __u16 *flags)
1841 {
1842         __u16 magic = le16_to_cpu(es->s_encoding);
1843         int i;
1844
1845         for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1846                 if (magic == ext4_sb_encoding_map[i].magic)
1847                         break;
1848
1849         if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1850                 return -EINVAL;
1851
1852         *encoding = &ext4_sb_encoding_map[i];
1853         *flags = le16_to_cpu(es->s_encoding_flags);
1854
1855         return 0;
1856 }
1857 #endif
1858
1859 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1860                             substring_t *args, unsigned long *journal_devnum,
1861                             unsigned int *journal_ioprio, int is_remount)
1862 {
1863         struct ext4_sb_info *sbi = EXT4_SB(sb);
1864         const struct mount_opts *m;
1865         kuid_t uid;
1866         kgid_t gid;
1867         int arg = 0;
1868
1869 #ifdef CONFIG_QUOTA
1870         if (token == Opt_usrjquota)
1871                 return set_qf_name(sb, USRQUOTA, &args[0]);
1872         else if (token == Opt_grpjquota)
1873                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1874         else if (token == Opt_offusrjquota)
1875                 return clear_qf_name(sb, USRQUOTA);
1876         else if (token == Opt_offgrpjquota)
1877                 return clear_qf_name(sb, GRPQUOTA);
1878 #endif
1879         switch (token) {
1880         case Opt_noacl:
1881         case Opt_nouser_xattr:
1882                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1883                 break;
1884         case Opt_sb:
1885                 return 1;       /* handled by get_sb_block() */
1886         case Opt_removed:
1887                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1888                 return 1;
1889         case Opt_abort:
1890                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1891                 return 1;
1892         case Opt_i_version:
1893                 sb->s_flags |= SB_I_VERSION;
1894                 return 1;
1895         case Opt_lazytime:
1896                 sb->s_flags |= SB_LAZYTIME;
1897                 return 1;
1898         case Opt_nolazytime:
1899                 sb->s_flags &= ~SB_LAZYTIME;
1900                 return 1;
1901         }
1902
1903         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1904                 if (token == m->token)
1905                         break;
1906
1907         if (m->token == Opt_err) {
1908                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1909                          "or missing value", opt);
1910                 return -1;
1911         }
1912
1913         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1914                 ext4_msg(sb, KERN_ERR,
1915                          "Mount option \"%s\" incompatible with ext2", opt);
1916                 return -1;
1917         }
1918         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1919                 ext4_msg(sb, KERN_ERR,
1920                          "Mount option \"%s\" incompatible with ext3", opt);
1921                 return -1;
1922         }
1923
1924         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1925                 return -1;
1926         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1927                 return -1;
1928         if (m->flags & MOPT_EXPLICIT) {
1929                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1930                         set_opt2(sb, EXPLICIT_DELALLOC);
1931                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1932                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1933                 } else
1934                         return -1;
1935         }
1936         if (m->flags & MOPT_CLEAR_ERR)
1937                 clear_opt(sb, ERRORS_MASK);
1938         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1939                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1940                          "options when quota turned on");
1941                 return -1;
1942         }
1943
1944         if (m->flags & MOPT_NOSUPPORT) {
1945                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1946         } else if (token == Opt_commit) {
1947                 if (arg == 0)
1948                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1949                 else if (arg > INT_MAX / HZ) {
1950                         ext4_msg(sb, KERN_ERR,
1951                                  "Invalid commit interval %d, "
1952                                  "must be smaller than %d",
1953                                  arg, INT_MAX / HZ);
1954                         return -1;
1955                 }
1956                 sbi->s_commit_interval = HZ * arg;
1957         } else if (token == Opt_debug_want_extra_isize) {
1958                 if ((arg & 1) ||
1959                     (arg < 4) ||
1960                     (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
1961                         ext4_msg(sb, KERN_ERR,
1962                                  "Invalid want_extra_isize %d", arg);
1963                         return -1;
1964                 }
1965                 sbi->s_want_extra_isize = arg;
1966         } else if (token == Opt_max_batch_time) {
1967                 sbi->s_max_batch_time = arg;
1968         } else if (token == Opt_min_batch_time) {
1969                 sbi->s_min_batch_time = arg;
1970         } else if (token == Opt_inode_readahead_blks) {
1971                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1972                         ext4_msg(sb, KERN_ERR,
1973                                  "EXT4-fs: inode_readahead_blks must be "
1974                                  "0 or a power of 2 smaller than 2^31");
1975                         return -1;
1976                 }
1977                 sbi->s_inode_readahead_blks = arg;
1978         } else if (token == Opt_init_itable) {
1979                 set_opt(sb, INIT_INODE_TABLE);
1980                 if (!args->from)
1981                         arg = EXT4_DEF_LI_WAIT_MULT;
1982                 sbi->s_li_wait_mult = arg;
1983         } else if (token == Opt_max_dir_size_kb) {
1984                 sbi->s_max_dir_size_kb = arg;
1985         } else if (token == Opt_stripe) {
1986                 sbi->s_stripe = arg;
1987         } else if (token == Opt_resuid) {
1988                 uid = make_kuid(current_user_ns(), arg);
1989                 if (!uid_valid(uid)) {
1990                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1991                         return -1;
1992                 }
1993                 sbi->s_resuid = uid;
1994         } else if (token == Opt_resgid) {
1995                 gid = make_kgid(current_user_ns(), arg);
1996                 if (!gid_valid(gid)) {
1997                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1998                         return -1;
1999                 }
2000                 sbi->s_resgid = gid;
2001         } else if (token == Opt_journal_dev) {
2002                 if (is_remount) {
2003                         ext4_msg(sb, KERN_ERR,
2004                                  "Cannot specify journal on remount");
2005                         return -1;
2006                 }
2007                 *journal_devnum = arg;
2008         } else if (token == Opt_journal_path) {
2009                 char *journal_path;
2010                 struct inode *journal_inode;
2011                 struct path path;
2012                 int error;
2013
2014                 if (is_remount) {
2015                         ext4_msg(sb, KERN_ERR,
2016                                  "Cannot specify journal on remount");
2017                         return -1;
2018                 }
2019                 journal_path = match_strdup(&args[0]);
2020                 if (!journal_path) {
2021                         ext4_msg(sb, KERN_ERR, "error: could not dup "
2022                                 "journal device string");
2023                         return -1;
2024                 }
2025
2026                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2027                 if (error) {
2028                         ext4_msg(sb, KERN_ERR, "error: could not find "
2029                                 "journal device path: error %d", error);
2030                         kfree(journal_path);
2031                         return -1;
2032                 }
2033
2034                 journal_inode = d_inode(path.dentry);
2035                 if (!S_ISBLK(journal_inode->i_mode)) {
2036                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
2037                                 "is not a block device", journal_path);
2038                         path_put(&path);
2039                         kfree(journal_path);
2040                         return -1;
2041                 }
2042
2043                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
2044                 path_put(&path);
2045                 kfree(journal_path);
2046         } else if (token == Opt_journal_ioprio) {
2047                 if (arg > 7) {
2048                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2049                                  " (must be 0-7)");
2050                         return -1;
2051                 }
2052                 *journal_ioprio =
2053                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2054         } else if (token == Opt_test_dummy_encryption) {
2055 #ifdef CONFIG_FS_ENCRYPTION
2056                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
2057                 ext4_msg(sb, KERN_WARNING,
2058                          "Test dummy encryption mode enabled");
2059 #else
2060                 ext4_msg(sb, KERN_WARNING,
2061                          "Test dummy encryption mount option ignored");
2062 #endif
2063         } else if (m->flags & MOPT_DATAJ) {
2064                 if (is_remount) {
2065                         if (!sbi->s_journal)
2066                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2067                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2068                                 ext4_msg(sb, KERN_ERR,
2069                                          "Cannot change data mode on remount");
2070                                 return -1;
2071                         }
2072                 } else {
2073                         clear_opt(sb, DATA_FLAGS);
2074                         sbi->s_mount_opt |= m->mount_opt;
2075                 }
2076 #ifdef CONFIG_QUOTA
2077         } else if (m->flags & MOPT_QFMT) {
2078                 if (sb_any_quota_loaded(sb) &&
2079                     sbi->s_jquota_fmt != m->mount_opt) {
2080                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2081                                  "quota options when quota turned on");
2082                         return -1;
2083                 }
2084                 if (ext4_has_feature_quota(sb)) {
2085                         ext4_msg(sb, KERN_INFO,
2086                                  "Quota format mount options ignored "
2087                                  "when QUOTA feature is enabled");
2088                         return 1;
2089                 }
2090                 sbi->s_jquota_fmt = m->mount_opt;
2091 #endif
2092         } else if (token == Opt_dax) {
2093 #ifdef CONFIG_FS_DAX
2094                 ext4_msg(sb, KERN_WARNING,
2095                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2096                 sbi->s_mount_opt |= m->mount_opt;
2097 #else
2098                 ext4_msg(sb, KERN_INFO, "dax option not supported");
2099                 return -1;
2100 #endif
2101         } else if (token == Opt_data_err_abort) {
2102                 sbi->s_mount_opt |= m->mount_opt;
2103         } else if (token == Opt_data_err_ignore) {
2104                 sbi->s_mount_opt &= ~m->mount_opt;
2105         } else {
2106                 if (!args->from)
2107                         arg = 1;
2108                 if (m->flags & MOPT_CLEAR)
2109                         arg = !arg;
2110                 else if (unlikely(!(m->flags & MOPT_SET))) {
2111                         ext4_msg(sb, KERN_WARNING,
2112                                  "buggy handling of option %s", opt);
2113                         WARN_ON(1);
2114                         return -1;
2115                 }
2116                 if (arg != 0)
2117                         sbi->s_mount_opt |= m->mount_opt;
2118                 else
2119                         sbi->s_mount_opt &= ~m->mount_opt;
2120         }
2121         return 1;
2122 }
2123
2124 static int parse_options(char *options, struct super_block *sb,
2125                          unsigned long *journal_devnum,
2126                          unsigned int *journal_ioprio,
2127                          int is_remount)
2128 {
2129         struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2130         char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2131         substring_t args[MAX_OPT_ARGS];
2132         int token;
2133
2134         if (!options)
2135                 return 1;
2136
2137         while ((p = strsep(&options, ",")) != NULL) {
2138                 if (!*p)
2139                         continue;
2140                 /*
2141                  * Initialize args struct so we know whether arg was
2142                  * found; some options take optional arguments.
2143                  */
2144                 args[0].to = args[0].from = NULL;
2145                 token = match_token(p, tokens, args);
2146                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
2147                                      journal_ioprio, is_remount) < 0)
2148                         return 0;
2149         }
2150 #ifdef CONFIG_QUOTA
2151         /*
2152          * We do the test below only for project quotas. 'usrquota' and
2153          * 'grpquota' mount options are allowed even without quota feature
2154          * to support legacy quotas in quota files.
2155          */
2156         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2157                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2158                          "Cannot enable project quota enforcement.");
2159                 return 0;
2160         }
2161         usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2162         grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2163         if (usr_qf_name || grp_qf_name) {
2164                 if (test_opt(sb, USRQUOTA) && usr_qf_name)
2165                         clear_opt(sb, USRQUOTA);
2166
2167                 if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2168                         clear_opt(sb, GRPQUOTA);
2169
2170                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2171                         ext4_msg(sb, KERN_ERR, "old and new quota "
2172                                         "format mixing");
2173                         return 0;
2174                 }
2175
2176                 if (!sbi->s_jquota_fmt) {
2177                         ext4_msg(sb, KERN_ERR, "journaled quota format "
2178                                         "not specified");
2179                         return 0;
2180                 }
2181         }
2182 #endif
2183         return 1;
2184 }
2185
2186 static inline void ext4_show_quota_options(struct seq_file *seq,
2187                                            struct super_block *sb)
2188 {
2189 #if defined(CONFIG_QUOTA)
2190         struct ext4_sb_info *sbi = EXT4_SB(sb);
2191         char *usr_qf_name, *grp_qf_name;
2192
2193         if (sbi->s_jquota_fmt) {
2194                 char *fmtname = "";
2195
2196                 switch (sbi->s_jquota_fmt) {
2197                 case QFMT_VFS_OLD:
2198                         fmtname = "vfsold";
2199                         break;
2200                 case QFMT_VFS_V0:
2201                         fmtname = "vfsv0";
2202                         break;
2203                 case QFMT_VFS_V1:
2204                         fmtname = "vfsv1";
2205                         break;
2206                 }
2207                 seq_printf(seq, ",jqfmt=%s", fmtname);
2208         }
2209
2210         rcu_read_lock();
2211         usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2212         grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2213         if (usr_qf_name)
2214                 seq_show_option(seq, "usrjquota", usr_qf_name);
2215         if (grp_qf_name)
2216                 seq_show_option(seq, "grpjquota", grp_qf_name);
2217         rcu_read_unlock();
2218 #endif
2219 }
2220
2221 static const char *token2str(int token)
2222 {
2223         const struct match_token *t;
2224
2225         for (t = tokens; t->token != Opt_err; t++)
2226                 if (t->token == token && !strchr(t->pattern, '='))
2227                         break;
2228         return t->pattern;
2229 }
2230
2231 /*
2232  * Show an option if
2233  *  - it's set to a non-default value OR
2234  *  - if the per-sb default is different from the global default
2235  */
2236 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2237                               int nodefs)
2238 {
2239         struct ext4_sb_info *sbi = EXT4_SB(sb);
2240         struct ext4_super_block *es = sbi->s_es;
2241         int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2242         const struct mount_opts *m;
2243         char sep = nodefs ? '\n' : ',';
2244
2245 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2246 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2247
2248         if (sbi->s_sb_block != 1)
2249                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2250
2251         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2252                 int want_set = m->flags & MOPT_SET;
2253                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2254                     (m->flags & MOPT_CLEAR_ERR))
2255                         continue;
2256                 if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2257                         continue; /* skip if same as the default */
2258                 if ((want_set &&
2259                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2260                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2261                         continue; /* select Opt_noFoo vs Opt_Foo */
2262                 SEQ_OPTS_PRINT("%s", token2str(m->token));
2263         }
2264
2265         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2266             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2267                 SEQ_OPTS_PRINT("resuid=%u",
2268                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2269         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2270             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2271                 SEQ_OPTS_PRINT("resgid=%u",
2272                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2273         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2274         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2275                 SEQ_OPTS_PUTS("errors=remount-ro");
2276         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2277                 SEQ_OPTS_PUTS("errors=continue");
2278         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2279                 SEQ_OPTS_PUTS("errors=panic");
2280         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2281                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2282         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2283                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2284         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2285                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2286         if (sb->s_flags & SB_I_VERSION)
2287                 SEQ_OPTS_PUTS("i_version");
2288         if (nodefs || sbi->s_stripe)
2289                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2290         if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2291                         (sbi->s_mount_opt ^ def_mount_opt)) {
2292                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2293                         SEQ_OPTS_PUTS("data=journal");
2294                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2295                         SEQ_OPTS_PUTS("data=ordered");
2296                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2297                         SEQ_OPTS_PUTS("data=writeback");
2298         }
2299         if (nodefs ||
2300             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2301                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2302                                sbi->s_inode_readahead_blks);
2303
2304         if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2305                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2306                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2307         if (nodefs || sbi->s_max_dir_size_kb)
2308                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2309         if (test_opt(sb, DATA_ERR_ABORT))
2310                 SEQ_OPTS_PUTS("data_err=abort");
2311         if (DUMMY_ENCRYPTION_ENABLED(sbi))
2312                 SEQ_OPTS_PUTS("test_dummy_encryption");
2313
2314         ext4_show_quota_options(seq, sb);
2315         return 0;
2316 }
2317
2318 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2319 {
2320         return _ext4_show_options(seq, root->d_sb, 0);
2321 }
2322
2323 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2324 {
2325         struct super_block *sb = seq->private;
2326         int rc;
2327
2328         seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2329         rc = _ext4_show_options(seq, sb, 1);
2330         seq_puts(seq, "\n");
2331         return rc;
2332 }
2333
2334 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2335                             int read_only)
2336 {
2337         struct ext4_sb_info *sbi = EXT4_SB(sb);
2338         int err = 0;
2339
2340         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2341                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2342                          "forcing read-only mode");
2343                 err = -EROFS;
2344         }
2345         if (read_only)
2346                 goto done;
2347         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2348                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2349                          "running e2fsck is recommended");
2350         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2351                 ext4_msg(sb, KERN_WARNING,
2352                          "warning: mounting fs with errors, "
2353                          "running e2fsck is recommended");
2354         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2355                  le16_to_cpu(es->s_mnt_count) >=
2356                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2357                 ext4_msg(sb, KERN_WARNING,
2358                          "warning: maximal mount count reached, "
2359                          "running e2fsck is recommended");
2360         else if (le32_to_cpu(es->s_checkinterval) &&
2361                  (ext4_get_tstamp(es, s_lastcheck) +
2362                   le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2363                 ext4_msg(sb, KERN_WARNING,
2364                          "warning: checktime reached, "
2365                          "running e2fsck is recommended");
2366         if (!sbi->s_journal)
2367                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2368         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2369                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2370         le16_add_cpu(&es->s_mnt_count, 1);
2371         ext4_update_tstamp(es, s_mtime);
2372         if (sbi->s_journal)
2373                 ext4_set_feature_journal_needs_recovery(sb);
2374
2375         err = ext4_commit_super(sb, 1);
2376 done:
2377         if (test_opt(sb, DEBUG))
2378                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2379                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2380                         sb->s_blocksize,
2381                         sbi->s_groups_count,
2382                         EXT4_BLOCKS_PER_GROUP(sb),
2383                         EXT4_INODES_PER_GROUP(sb),
2384                         sbi->s_mount_opt, sbi->s_mount_opt2);
2385
2386         cleancache_init_fs(sb);
2387         return err;
2388 }
2389
2390 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2391 {
2392         struct ext4_sb_info *sbi = EXT4_SB(sb);
2393         struct flex_groups **old_groups, **new_groups;
2394         int size, i, j;
2395
2396         if (!sbi->s_log_groups_per_flex)
2397                 return 0;
2398
2399         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2400         if (size <= sbi->s_flex_groups_allocated)
2401                 return 0;
2402
2403         new_groups = kvzalloc(roundup_pow_of_two(size *
2404                               sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2405         if (!new_groups) {
2406                 ext4_msg(sb, KERN_ERR,
2407                          "not enough memory for %d flex group pointers", size);
2408                 return -ENOMEM;
2409         }
2410         for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2411                 new_groups[i] = kvzalloc(roundup_pow_of_two(
2412                                          sizeof(struct flex_groups)),
2413                                          GFP_KERNEL);
2414                 if (!new_groups[i]) {
2415                         for (j = sbi->s_flex_groups_allocated; j < i; j++)
2416                                 kvfree(new_groups[j]);
2417                         kvfree(new_groups);
2418                         ext4_msg(sb, KERN_ERR,
2419                                  "not enough memory for %d flex groups", size);
2420                         return -ENOMEM;
2421                 }
2422         }
2423         rcu_read_lock();
2424         old_groups = rcu_dereference(sbi->s_flex_groups);
2425         if (old_groups)
2426                 memcpy(new_groups, old_groups,
2427                        (sbi->s_flex_groups_allocated *
2428                         sizeof(struct flex_groups *)));
2429         rcu_read_unlock();
2430         rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2431         sbi->s_flex_groups_allocated = size;
2432         if (old_groups)
2433                 ext4_kvfree_array_rcu(old_groups);
2434         return 0;
2435 }
2436
2437 static int ext4_fill_flex_info(struct super_block *sb)
2438 {
2439         struct ext4_sb_info *sbi = EXT4_SB(sb);
2440         struct ext4_group_desc *gdp = NULL;
2441         struct flex_groups *fg;
2442         ext4_group_t flex_group;
2443         int i, err;
2444
2445         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2446         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2447                 sbi->s_log_groups_per_flex = 0;
2448                 return 1;
2449         }
2450
2451         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2452         if (err)
2453                 goto failed;
2454
2455         for (i = 0; i < sbi->s_groups_count; i++) {
2456                 gdp = ext4_get_group_desc(sb, i, NULL);
2457
2458                 flex_group = ext4_flex_group(sbi, i);
2459                 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2460                 atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2461                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2462                              &fg->free_clusters);
2463                 atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2464         }
2465
2466         return 1;
2467 failed:
2468         return 0;
2469 }
2470
2471 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2472                                    struct ext4_group_desc *gdp)
2473 {
2474         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2475         __u16 crc = 0;
2476         __le32 le_group = cpu_to_le32(block_group);
2477         struct ext4_sb_info *sbi = EXT4_SB(sb);
2478
2479         if (ext4_has_metadata_csum(sbi->s_sb)) {
2480                 /* Use new metadata_csum algorithm */
2481                 __u32 csum32;
2482                 __u16 dummy_csum = 0;
2483
2484                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2485                                      sizeof(le_group));
2486                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2487                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2488                                      sizeof(dummy_csum));
2489                 offset += sizeof(dummy_csum);
2490                 if (offset < sbi->s_desc_size)
2491                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2492                                              sbi->s_desc_size - offset);
2493
2494                 crc = csum32 & 0xFFFF;
2495                 goto out;
2496         }
2497
2498         /* old crc16 code */
2499         if (!ext4_has_feature_gdt_csum(sb))
2500                 return 0;
2501
2502         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2503         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2504         crc = crc16(crc, (__u8 *)gdp, offset);
2505         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2506         /* for checksum of struct ext4_group_desc do the rest...*/
2507         if (ext4_has_feature_64bit(sb) &&
2508             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2509                 crc = crc16(crc, (__u8 *)gdp + offset,
2510                             le16_to_cpu(sbi->s_es->s_desc_size) -
2511                                 offset);
2512
2513 out:
2514         return cpu_to_le16(crc);
2515 }
2516
2517 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2518                                 struct ext4_group_desc *gdp)
2519 {
2520         if (ext4_has_group_desc_csum(sb) &&
2521             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2522                 return 0;
2523
2524         return 1;
2525 }
2526
2527 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2528                               struct ext4_group_desc *gdp)
2529 {
2530         if (!ext4_has_group_desc_csum(sb))
2531                 return;
2532         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2533 }
2534
2535 /* Called at mount-time, super-block is locked */
2536 static int ext4_check_descriptors(struct super_block *sb,
2537                                   ext4_fsblk_t sb_block,
2538                                   ext4_group_t *first_not_zeroed)
2539 {
2540         struct ext4_sb_info *sbi = EXT4_SB(sb);
2541         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2542         ext4_fsblk_t last_block;
2543         ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2544         ext4_fsblk_t block_bitmap;
2545         ext4_fsblk_t inode_bitmap;
2546         ext4_fsblk_t inode_table;
2547         int flexbg_flag = 0;
2548         ext4_group_t i, grp = sbi->s_groups_count;
2549
2550         if (ext4_has_feature_flex_bg(sb))
2551                 flexbg_flag = 1;
2552
2553         ext4_debug("Checking group descriptors");
2554
2555         for (i = 0; i < sbi->s_groups_count; i++) {
2556                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2557
2558                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2559                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2560                 else
2561                         last_block = first_block +
2562                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2563
2564                 if ((grp == sbi->s_groups_count) &&
2565                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2566                         grp = i;
2567
2568                 block_bitmap = ext4_block_bitmap(sb, gdp);
2569                 if (block_bitmap == sb_block) {
2570                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2571                                  "Block bitmap for group %u overlaps "
2572                                  "superblock", i);
2573                         if (!sb_rdonly(sb))
2574                                 return 0;
2575                 }
2576                 if (block_bitmap >= sb_block + 1 &&
2577                     block_bitmap <= last_bg_block) {
2578                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2579                                  "Block bitmap for group %u overlaps "
2580                                  "block group descriptors", i);
2581                         if (!sb_rdonly(sb))
2582                                 return 0;
2583                 }
2584                 if (block_bitmap < first_block || block_bitmap > last_block) {
2585                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2586                                "Block bitmap for group %u not in group "
2587                                "(block %llu)!", i, block_bitmap);
2588                         return 0;
2589                 }
2590                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2591                 if (inode_bitmap == sb_block) {
2592                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2593                                  "Inode bitmap for group %u overlaps "
2594                                  "superblock", i);
2595                         if (!sb_rdonly(sb))
2596                                 return 0;
2597                 }
2598                 if (inode_bitmap >= sb_block + 1 &&
2599                     inode_bitmap <= last_bg_block) {
2600                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2601                                  "Inode bitmap for group %u overlaps "
2602                                  "block group descriptors", i);
2603                         if (!sb_rdonly(sb))
2604                                 return 0;
2605                 }
2606                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2607                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2608                                "Inode bitmap for group %u not in group "
2609                                "(block %llu)!", i, inode_bitmap);
2610                         return 0;
2611                 }
2612                 inode_table = ext4_inode_table(sb, gdp);
2613                 if (inode_table == sb_block) {
2614                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2615                                  "Inode table for group %u overlaps "
2616                                  "superblock", i);
2617                         if (!sb_rdonly(sb))
2618                                 return 0;
2619                 }
2620                 if (inode_table >= sb_block + 1 &&
2621                     inode_table <= last_bg_block) {
2622                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2623                                  "Inode table for group %u overlaps "
2624                                  "block group descriptors", i);
2625                         if (!sb_rdonly(sb))
2626                                 return 0;
2627                 }
2628                 if (inode_table < first_block ||
2629                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2630                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2631                                "Inode table for group %u not in group "
2632                                "(block %llu)!", i, inode_table);
2633                         return 0;
2634                 }
2635                 ext4_lock_group(sb, i);
2636                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2637                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2638                                  "Checksum for group %u failed (%u!=%u)",
2639                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2640                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2641                         if (!sb_rdonly(sb)) {
2642                                 ext4_unlock_group(sb, i);
2643                                 return 0;
2644                         }
2645                 }
2646                 ext4_unlock_group(sb, i);
2647                 if (!flexbg_flag)
2648                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2649         }
2650         if (NULL != first_not_zeroed)
2651                 *first_not_zeroed = grp;
2652         return 1;
2653 }
2654
2655 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2656  * the superblock) which were deleted from all directories, but held open by
2657  * a process at the time of a crash.  We walk the list and try to delete these
2658  * inodes at recovery time (only with a read-write filesystem).
2659  *
2660  * In order to keep the orphan inode chain consistent during traversal (in
2661  * case of crash during recovery), we link each inode into the superblock
2662  * orphan list_head and handle it the same way as an inode deletion during
2663  * normal operation (which journals the operations for us).
2664  *
2665  * We only do an iget() and an iput() on each inode, which is very safe if we
2666  * accidentally point at an in-use or already deleted inode.  The worst that
2667  * can happen in this case is that we get a "bit already cleared" message from
2668  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2669  * e2fsck was run on this filesystem, and it must have already done the orphan
2670  * inode cleanup for us, so we can safely abort without any further action.
2671  */
2672 static void ext4_orphan_cleanup(struct super_block *sb,
2673                                 struct ext4_super_block *es)
2674 {
2675         unsigned int s_flags = sb->s_flags;
2676         int ret, nr_orphans = 0, nr_truncates = 0;
2677 #ifdef CONFIG_QUOTA
2678         int quota_update = 0;
2679         int i;
2680 #endif
2681         if (!es->s_last_orphan) {
2682                 jbd_debug(4, "no orphan inodes to clean up\n");
2683                 return;
2684         }
2685
2686         if (bdev_read_only(sb->s_bdev)) {
2687                 ext4_msg(sb, KERN_ERR, "write access "
2688                         "unavailable, skipping orphan cleanup");
2689                 return;
2690         }
2691
2692         /* Check if feature set would not allow a r/w mount */
2693         if (!ext4_feature_set_ok(sb, 0)) {
2694                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2695                          "unknown ROCOMPAT features");
2696                 return;
2697         }
2698
2699         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2700                 /* don't clear list on RO mount w/ errors */
2701                 if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2702                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2703                                   "clearing orphan list.\n");
2704                         es->s_last_orphan = 0;
2705                 }
2706                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2707                 return;
2708         }
2709
2710         if (s_flags & SB_RDONLY) {
2711                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2712                 sb->s_flags &= ~SB_RDONLY;
2713         }
2714 #ifdef CONFIG_QUOTA
2715         /* Needed for iput() to work correctly and not trash data */
2716         sb->s_flags |= SB_ACTIVE;
2717
2718         /*
2719          * Turn on quotas which were not enabled for read-only mounts if
2720          * filesystem has quota feature, so that they are updated correctly.
2721          */
2722         if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2723                 int ret = ext4_enable_quotas(sb);
2724
2725                 if (!ret)
2726                         quota_update = 1;
2727                 else
2728                         ext4_msg(sb, KERN_ERR,
2729                                 "Cannot turn on quotas: error %d", ret);
2730         }
2731
2732         /* Turn on journaled quotas used for old sytle */
2733         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2734                 if (EXT4_SB(sb)->s_qf_names[i]) {
2735                         int ret = ext4_quota_on_mount(sb, i);
2736
2737                         if (!ret)
2738                                 quota_update = 1;
2739                         else
2740                                 ext4_msg(sb, KERN_ERR,
2741                                         "Cannot turn on journaled "
2742                                         "quota: type %d: error %d", i, ret);
2743                 }
2744         }
2745 #endif
2746
2747         while (es->s_last_orphan) {
2748                 struct inode *inode;
2749
2750                 /*
2751                  * We may have encountered an error during cleanup; if
2752                  * so, skip the rest.
2753                  */
2754                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2755                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2756                         es->s_last_orphan = 0;
2757                         break;
2758                 }
2759
2760                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2761                 if (IS_ERR(inode)) {
2762                         es->s_last_orphan = 0;
2763                         break;
2764                 }
2765
2766                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2767                 dquot_initialize(inode);
2768                 if (inode->i_nlink) {
2769                         if (test_opt(sb, DEBUG))
2770                                 ext4_msg(sb, KERN_DEBUG,
2771                                         "%s: truncating inode %lu to %lld bytes",
2772                                         __func__, inode->i_ino, inode->i_size);
2773                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2774                                   inode->i_ino, inode->i_size);
2775                         inode_lock(inode);
2776                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2777                         ret = ext4_truncate(inode);
2778                         if (ret)
2779                                 ext4_std_error(inode->i_sb, ret);
2780                         inode_unlock(inode);
2781                         nr_truncates++;
2782                 } else {
2783                         if (test_opt(sb, DEBUG))
2784                                 ext4_msg(sb, KERN_DEBUG,
2785                                         "%s: deleting unreferenced inode %lu",
2786                                         __func__, inode->i_ino);
2787                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2788                                   inode->i_ino);
2789                         nr_orphans++;
2790                 }
2791                 iput(inode);  /* The delete magic happens here! */
2792         }
2793
2794 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2795
2796         if (nr_orphans)
2797                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2798                        PLURAL(nr_orphans));
2799         if (nr_truncates)
2800                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2801                        PLURAL(nr_truncates));
2802 #ifdef CONFIG_QUOTA
2803         /* Turn off quotas if they were enabled for orphan cleanup */
2804         if (quota_update) {
2805                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2806                         if (sb_dqopt(sb)->files[i])
2807                                 dquot_quota_off(sb, i);
2808                 }
2809         }
2810 #endif
2811         sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2812 }
2813
2814 /*
2815  * Maximal extent format file size.
2816  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2817  * extent format containers, within a sector_t, and within i_blocks
2818  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2819  * so that won't be a limiting factor.
2820  *
2821  * However there is other limiting factor. We do store extents in the form
2822  * of starting block and length, hence the resulting length of the extent
2823  * covering maximum file size must fit into on-disk format containers as
2824  * well. Given that length is always by 1 unit bigger than max unit (because
2825  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2826  *
2827  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2828  */
2829 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2830 {
2831         loff_t res;
2832         loff_t upper_limit = MAX_LFS_FILESIZE;
2833
2834         BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2835
2836         if (!has_huge_files) {
2837                 upper_limit = (1LL << 32) - 1;
2838
2839                 /* total blocks in file system block size */
2840                 upper_limit >>= (blkbits - 9);
2841                 upper_limit <<= blkbits;
2842         }
2843
2844         /*
2845          * 32-bit extent-start container, ee_block. We lower the maxbytes
2846          * by one fs block, so ee_len can cover the extent of maximum file
2847          * size
2848          */
2849         res = (1LL << 32) - 1;
2850         res <<= blkbits;
2851
2852         /* Sanity check against vm- & vfs- imposed limits */
2853         if (res > upper_limit)
2854                 res = upper_limit;
2855
2856         return res;
2857 }
2858
2859 /*
2860  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2861  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2862  * We need to be 1 filesystem block less than the 2^48 sector limit.
2863  */
2864 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2865 {
2866         loff_t res = EXT4_NDIR_BLOCKS;
2867         int meta_blocks;
2868         loff_t upper_limit;
2869         /* This is calculated to be the largest file size for a dense, block
2870          * mapped file such that the file's total number of 512-byte sectors,
2871          * including data and all indirect blocks, does not exceed (2^48 - 1).
2872          *
2873          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2874          * number of 512-byte sectors of the file.
2875          */
2876
2877         if (!has_huge_files) {
2878                 /*
2879                  * !has_huge_files or implies that the inode i_block field
2880                  * represents total file blocks in 2^32 512-byte sectors ==
2881                  * size of vfs inode i_blocks * 8
2882                  */
2883                 upper_limit = (1LL << 32) - 1;
2884
2885                 /* total blocks in file system block size */
2886                 upper_limit >>= (bits - 9);
2887
2888         } else {
2889                 /*
2890                  * We use 48 bit ext4_inode i_blocks
2891                  * With EXT4_HUGE_FILE_FL set the i_blocks
2892                  * represent total number of blocks in
2893                  * file system block size
2894                  */
2895                 upper_limit = (1LL << 48) - 1;
2896
2897         }
2898
2899         /* indirect blocks */
2900         meta_blocks = 1;
2901         /* double indirect blocks */
2902         meta_blocks += 1 + (1LL << (bits-2));
2903         /* tripple indirect blocks */
2904         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2905
2906         upper_limit -= meta_blocks;
2907         upper_limit <<= bits;
2908
2909         res += 1LL << (bits-2);
2910         res += 1LL << (2*(bits-2));
2911         res += 1LL << (3*(bits-2));
2912         res <<= bits;
2913         if (res > upper_limit)
2914                 res = upper_limit;
2915
2916         if (res > MAX_LFS_FILESIZE)
2917                 res = MAX_LFS_FILESIZE;
2918
2919         return res;
2920 }
2921
2922 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2923                                    ext4_fsblk_t logical_sb_block, int nr)
2924 {
2925         struct ext4_sb_info *sbi = EXT4_SB(sb);
2926         ext4_group_t bg, first_meta_bg;
2927         int has_super = 0;
2928
2929         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2930
2931         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2932                 return logical_sb_block + nr + 1;
2933         bg = sbi->s_desc_per_block * nr;
2934         if (ext4_bg_has_super(sb, bg))
2935                 has_super = 1;
2936
2937         /*
2938          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2939          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2940          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2941          * compensate.
2942          */
2943         if (sb->s_blocksize == 1024 && nr == 0 &&
2944             le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2945                 has_super++;
2946
2947         return (has_super + ext4_group_first_block_no(sb, bg));
2948 }
2949
2950 /**
2951  * ext4_get_stripe_size: Get the stripe size.
2952  * @sbi: In memory super block info
2953  *
2954  * If we have specified it via mount option, then
2955  * use the mount option value. If the value specified at mount time is
2956  * greater than the blocks per group use the super block value.
2957  * If the super block value is greater than blocks per group return 0.
2958  * Allocator needs it be less than blocks per group.
2959  *
2960  */
2961 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2962 {
2963         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2964         unsigned long stripe_width =
2965                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2966         int ret;
2967
2968         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2969                 ret = sbi->s_stripe;
2970         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2971                 ret = stripe_width;
2972         else if (stride && stride <= sbi->s_blocks_per_group)
2973                 ret = stride;
2974         else
2975                 ret = 0;
2976
2977         /*
2978          * If the stripe width is 1, this makes no sense and
2979          * we set it to 0 to turn off stripe handling code.
2980          */
2981         if (ret <= 1)
2982                 ret = 0;
2983
2984         return ret;
2985 }
2986
2987 /*
2988  * Check whether this filesystem can be mounted based on
2989  * the features present and the RDONLY/RDWR mount requested.
2990  * Returns 1 if this filesystem can be mounted as requested,
2991  * 0 if it cannot be.
2992  */
2993 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2994 {
2995         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2996                 ext4_msg(sb, KERN_ERR,
2997                         "Couldn't mount because of "
2998                         "unsupported optional features (%x)",
2999                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3000                         ~EXT4_FEATURE_INCOMPAT_SUPP));
3001                 return 0;
3002         }
3003
3004 #ifndef CONFIG_UNICODE
3005         if (ext4_has_feature_casefold(sb)) {
3006                 ext4_msg(sb, KERN_ERR,
3007                          "Filesystem with casefold feature cannot be "
3008                          "mounted without CONFIG_UNICODE");
3009                 return 0;
3010         }
3011 #endif
3012
3013         if (readonly)
3014                 return 1;
3015
3016         if (ext4_has_feature_readonly(sb)) {
3017                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3018                 sb->s_flags |= SB_RDONLY;
3019                 return 1;
3020         }
3021
3022         /* Check that feature set is OK for a read-write mount */
3023         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3024                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3025                          "unsupported optional features (%x)",
3026                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3027                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
3028                 return 0;
3029         }
3030         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3031                 ext4_msg(sb, KERN_ERR,
3032                          "Can't support bigalloc feature without "
3033                          "extents feature\n");
3034                 return 0;
3035         }
3036
3037 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3038         if (!readonly && (ext4_has_feature_quota(sb) ||
3039                           ext4_has_feature_project(sb))) {
3040                 ext4_msg(sb, KERN_ERR,
3041                          "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3042                 return 0;
3043         }
3044 #endif  /* CONFIG_QUOTA */
3045         return 1;
3046 }
3047
3048 /*
3049  * This function is called once a day if we have errors logged
3050  * on the file system
3051  */
3052 static void print_daily_error_info(struct timer_list *t)
3053 {
3054         struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3055         struct super_block *sb = sbi->s_sb;
3056         struct ext4_super_block *es = sbi->s_es;
3057
3058         if (es->s_error_count)
3059                 /* fsck newer than v1.41.13 is needed to clean this condition. */
3060                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3061                          le32_to_cpu(es->s_error_count));
3062         if (es->s_first_error_time) {
3063                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3064                        sb->s_id,
3065                        ext4_get_tstamp(es, s_first_error_time),
3066                        (int) sizeof(es->s_first_error_func),
3067                        es->s_first_error_func,
3068                        le32_to_cpu(es->s_first_error_line));
3069                 if (es->s_first_error_ino)
3070                         printk(KERN_CONT ": inode %u",
3071                                le32_to_cpu(es->s_first_error_ino));
3072                 if (es->s_first_error_block)
3073                         printk(KERN_CONT ": block %llu", (unsigned long long)
3074                                le64_to_cpu(es->s_first_error_block));
3075                 printk(KERN_CONT "\n");
3076         }
3077         if (es->s_last_error_time) {
3078                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3079                        sb->s_id,
3080                        ext4_get_tstamp(es, s_last_error_time),
3081                        (int) sizeof(es->s_last_error_func),
3082                        es->s_last_error_func,
3083                        le32_to_cpu(es->s_last_error_line));
3084                 if (es->s_last_error_ino)
3085                         printk(KERN_CONT ": inode %u",
3086                                le32_to_cpu(es->s_last_error_ino));
3087                 if (es->s_last_error_block)
3088                         printk(KERN_CONT ": block %llu", (unsigned long long)
3089                                le64_to_cpu(es->s_last_error_block));
3090                 printk(KERN_CONT "\n");
3091         }
3092         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3093 }
3094
3095 /* Find next suitable group and run ext4_init_inode_table */
3096 static int ext4_run_li_request(struct ext4_li_request *elr)
3097 {
3098         struct ext4_group_desc *gdp = NULL;
3099         ext4_group_t group, ngroups;
3100         struct super_block *sb;
3101         unsigned long timeout = 0;
3102         int ret = 0;
3103
3104         sb = elr->lr_super;
3105         ngroups = EXT4_SB(sb)->s_groups_count;
3106
3107         for (group = elr->lr_next_group; group < ngroups; group++) {
3108                 gdp = ext4_get_group_desc(sb, group, NULL);
3109                 if (!gdp) {
3110                         ret = 1;
3111                         break;
3112                 }
3113
3114                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3115                         break;
3116         }
3117
3118         if (group >= ngroups)
3119                 ret = 1;
3120
3121         if (!ret) {
3122                 timeout = jiffies;
3123                 ret = ext4_init_inode_table(sb, group,
3124                                             elr->lr_timeout ? 0 : 1);
3125                 if (elr->lr_timeout == 0) {
3126                         timeout = (jiffies - timeout) *
3127                                   elr->lr_sbi->s_li_wait_mult;
3128                         elr->lr_timeout = timeout;
3129                 }
3130                 elr->lr_next_sched = jiffies + elr->lr_timeout;
3131                 elr->lr_next_group = group + 1;
3132         }
3133         return ret;
3134 }
3135
3136 /*
3137  * Remove lr_request from the list_request and free the
3138  * request structure. Should be called with li_list_mtx held
3139  */
3140 static void ext4_remove_li_request(struct ext4_li_request *elr)
3141 {
3142         struct ext4_sb_info *sbi;
3143
3144         if (!elr)
3145                 return;
3146
3147         sbi = elr->lr_sbi;
3148
3149         list_del(&elr->lr_request);
3150         sbi->s_li_request = NULL;
3151         kfree(elr);
3152 }
3153
3154 static void ext4_unregister_li_request(struct super_block *sb)
3155 {
3156         mutex_lock(&ext4_li_mtx);
3157         if (!ext4_li_info) {
3158                 mutex_unlock(&ext4_li_mtx);
3159                 return;
3160         }
3161
3162         mutex_lock(&ext4_li_info->li_list_mtx);
3163         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3164         mutex_unlock(&ext4_li_info->li_list_mtx);
3165         mutex_unlock(&ext4_li_mtx);
3166 }
3167
3168 static struct task_struct *ext4_lazyinit_task;
3169
3170 /*
3171  * This is the function where ext4lazyinit thread lives. It walks
3172  * through the request list searching for next scheduled filesystem.
3173  * When such a fs is found, run the lazy initialization request
3174  * (ext4_rn_li_request) and keep track of the time spend in this
3175  * function. Based on that time we compute next schedule time of
3176  * the request. When walking through the list is complete, compute
3177  * next waking time and put itself into sleep.
3178  */
3179 static int ext4_lazyinit_thread(void *arg)
3180 {
3181         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3182         struct list_head *pos, *n;
3183         struct ext4_li_request *elr;
3184         unsigned long next_wakeup, cur;
3185
3186         BUG_ON(NULL == eli);
3187
3188 cont_thread:
3189         while (true) {
3190                 next_wakeup = MAX_JIFFY_OFFSET;
3191
3192                 mutex_lock(&eli->li_list_mtx);
3193                 if (list_empty(&eli->li_request_list)) {
3194                         mutex_unlock(&eli->li_list_mtx);
3195                         goto exit_thread;
3196                 }
3197                 list_for_each_safe(pos, n, &eli->li_request_list) {
3198                         int err = 0;
3199                         int progress = 0;
3200                         elr = list_entry(pos, struct ext4_li_request,
3201                                          lr_request);
3202
3203                         if (time_before(jiffies, elr->lr_next_sched)) {
3204                                 if (time_before(elr->lr_next_sched, next_wakeup))
3205                                         next_wakeup = elr->lr_next_sched;
3206                                 continue;
3207                         }
3208                         if (down_read_trylock(&elr->lr_super->s_umount)) {
3209                                 if (sb_start_write_trylock(elr->lr_super)) {
3210                                         progress = 1;
3211                                         /*
3212                                          * We hold sb->s_umount, sb can not
3213                                          * be removed from the list, it is
3214                                          * now safe to drop li_list_mtx
3215                                          */
3216                                         mutex_unlock(&eli->li_list_mtx);
3217                                         err = ext4_run_li_request(elr);
3218                                         sb_end_write(elr->lr_super);
3219                                         mutex_lock(&eli->li_list_mtx);
3220                                         n = pos->next;
3221                                 }
3222                                 up_read((&elr->lr_super->s_umount));
3223                         }
3224                         /* error, remove the lazy_init job */
3225                         if (err) {
3226                                 ext4_remove_li_request(elr);
3227                                 continue;
3228                         }
3229                         if (!progress) {
3230                                 elr->lr_next_sched = jiffies +
3231                                         (prandom_u32()
3232                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3233                         }
3234                         if (time_before(elr->lr_next_sched, next_wakeup))
3235                                 next_wakeup = elr->lr_next_sched;
3236                 }
3237                 mutex_unlock(&eli->li_list_mtx);
3238
3239                 try_to_freeze();
3240
3241                 cur = jiffies;
3242                 if ((time_after_eq(cur, next_wakeup)) ||
3243                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3244                         cond_resched();
3245                         continue;
3246                 }
3247
3248                 schedule_timeout_interruptible(next_wakeup - cur);
3249
3250                 if (kthread_should_stop()) {
3251                         ext4_clear_request_list();
3252                         goto exit_thread;
3253                 }
3254         }
3255
3256 exit_thread:
3257         /*
3258          * It looks like the request list is empty, but we need
3259          * to check it under the li_list_mtx lock, to prevent any
3260          * additions into it, and of course we should lock ext4_li_mtx
3261          * to atomically free the list and ext4_li_info, because at
3262          * this point another ext4 filesystem could be registering
3263          * new one.
3264          */
3265         mutex_lock(&ext4_li_mtx);
3266         mutex_lock(&eli->li_list_mtx);
3267         if (!list_empty(&eli->li_request_list)) {
3268                 mutex_unlock(&eli->li_list_mtx);
3269                 mutex_unlock(&ext4_li_mtx);
3270                 goto cont_thread;
3271         }
3272         mutex_unlock(&eli->li_list_mtx);
3273         kfree(ext4_li_info);
3274         ext4_li_info = NULL;
3275         mutex_unlock(&ext4_li_mtx);
3276
3277         return 0;
3278 }
3279
3280 static void ext4_clear_request_list(void)
3281 {
3282         struct list_head *pos, *n;
3283         struct ext4_li_request *elr;
3284
3285         mutex_lock(&ext4_li_info->li_list_mtx);
3286         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3287                 elr = list_entry(pos, struct ext4_li_request,
3288                                  lr_request);
3289                 ext4_remove_li_request(elr);
3290         }
3291         mutex_unlock(&ext4_li_info->li_list_mtx);
3292 }
3293
3294 static int ext4_run_lazyinit_thread(void)
3295 {
3296         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3297                                          ext4_li_info, "ext4lazyinit");
3298         if (IS_ERR(ext4_lazyinit_task)) {
3299                 int err = PTR_ERR(ext4_lazyinit_task);
3300                 ext4_clear_request_list();
3301                 kfree(ext4_li_info);
3302                 ext4_li_info = NULL;
3303                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3304                                  "initialization thread\n",
3305                                  err);
3306                 return err;
3307         }
3308         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3309         return 0;
3310 }
3311
3312 /*
3313  * Check whether it make sense to run itable init. thread or not.
3314  * If there is at least one uninitialized inode table, return
3315  * corresponding group number, else the loop goes through all
3316  * groups and return total number of groups.
3317  */
3318 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3319 {
3320         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3321         struct ext4_group_desc *gdp = NULL;
3322
3323         if (!ext4_has_group_desc_csum(sb))
3324                 return ngroups;
3325
3326         for (group = 0; group < ngroups; group++) {
3327                 gdp = ext4_get_group_desc(sb, group, NULL);
3328                 if (!gdp)
3329                         continue;
3330
3331                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3332                         break;
3333         }
3334
3335         return group;
3336 }
3337
3338 static int ext4_li_info_new(void)
3339 {
3340         struct ext4_lazy_init *eli = NULL;
3341
3342         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3343         if (!eli)
3344                 return -ENOMEM;
3345
3346         INIT_LIST_HEAD(&eli->li_request_list);
3347         mutex_init(&eli->li_list_mtx);
3348
3349         eli->li_state |= EXT4_LAZYINIT_QUIT;
3350
3351         ext4_li_info = eli;
3352
3353         return 0;
3354 }
3355
3356 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3357                                             ext4_group_t start)
3358 {
3359         struct ext4_sb_info *sbi = EXT4_SB(sb);
3360         struct ext4_li_request *elr;
3361
3362         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3363         if (!elr)
3364                 return NULL;
3365
3366         elr->lr_super = sb;
3367         elr->lr_sbi = sbi;
3368         elr->lr_next_group = start;
3369
3370         /*
3371          * Randomize first schedule time of the request to
3372          * spread the inode table initialization requests
3373          * better.
3374          */
3375         elr->lr_next_sched = jiffies + (prandom_u32() %
3376                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3377         return elr;
3378 }
3379
3380 int ext4_register_li_request(struct super_block *sb,
3381                              ext4_group_t first_not_zeroed)
3382 {
3383         struct ext4_sb_info *sbi = EXT4_SB(sb);
3384         struct ext4_li_request *elr = NULL;
3385         ext4_group_t ngroups = sbi->s_groups_count;
3386         int ret = 0;
3387
3388         mutex_lock(&ext4_li_mtx);
3389         if (sbi->s_li_request != NULL) {
3390                 /*
3391                  * Reset timeout so it can be computed again, because
3392                  * s_li_wait_mult might have changed.
3393                  */
3394                 sbi->s_li_request->lr_timeout = 0;
3395                 goto out;
3396         }
3397
3398         if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3399             !test_opt(sb, INIT_INODE_TABLE))
3400                 goto out;
3401
3402         elr = ext4_li_request_new(sb, first_not_zeroed);
3403         if (!elr) {
3404                 ret = -ENOMEM;
3405                 goto out;
3406         }
3407
3408         if (NULL == ext4_li_info) {
3409                 ret = ext4_li_info_new();
3410                 if (ret)
3411                         goto out;
3412         }
3413
3414         mutex_lock(&ext4_li_info->li_list_mtx);
3415         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3416         mutex_unlock(&ext4_li_info->li_list_mtx);
3417
3418         sbi->s_li_request = elr;
3419         /*
3420          * set elr to NULL here since it has been inserted to
3421          * the request_list and the removal and free of it is
3422          * handled by ext4_clear_request_list from now on.
3423          */
3424         elr = NULL;
3425
3426         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3427                 ret = ext4_run_lazyinit_thread();
3428                 if (ret)
3429                         goto out;
3430         }
3431 out:
3432         mutex_unlock(&ext4_li_mtx);
3433         if (ret)
3434                 kfree(elr);
3435         return ret;
3436 }
3437
3438 /*
3439  * We do not need to lock anything since this is called on
3440  * module unload.
3441  */
3442 static void ext4_destroy_lazyinit_thread(void)
3443 {
3444         /*
3445          * If thread exited earlier
3446          * there's nothing to be done.
3447          */
3448         if (!ext4_li_info || !ext4_lazyinit_task)
3449                 return;
3450
3451         kthread_stop(ext4_lazyinit_task);
3452 }
3453
3454 static int set_journal_csum_feature_set(struct super_block *sb)
3455 {
3456         int ret = 1;
3457         int compat, incompat;
3458         struct ext4_sb_info *sbi = EXT4_SB(sb);
3459
3460         if (ext4_has_metadata_csum(sb)) {
3461                 /* journal checksum v3 */
3462                 compat = 0;
3463                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3464         } else {
3465                 /* journal checksum v1 */
3466                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3467                 incompat = 0;
3468         }
3469
3470         jbd2_journal_clear_features(sbi->s_journal,
3471                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3472                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3473                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3474         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3475                 ret = jbd2_journal_set_features(sbi->s_journal,
3476                                 compat, 0,
3477                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3478                                 incompat);
3479         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3480                 ret = jbd2_journal_set_features(sbi->s_journal,
3481                                 compat, 0,
3482                                 incompat);
3483                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3484                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3485         } else {
3486                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3487                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3488         }
3489
3490         return ret;
3491 }
3492
3493 /*
3494  * Note: calculating the overhead so we can be compatible with
3495  * historical BSD practice is quite difficult in the face of
3496  * clusters/bigalloc.  This is because multiple metadata blocks from
3497  * different block group can end up in the same allocation cluster.
3498  * Calculating the exact overhead in the face of clustered allocation
3499  * requires either O(all block bitmaps) in memory or O(number of block
3500  * groups**2) in time.  We will still calculate the superblock for
3501  * older file systems --- and if we come across with a bigalloc file
3502  * system with zero in s_overhead_clusters the estimate will be close to
3503  * correct especially for very large cluster sizes --- but for newer
3504  * file systems, it's better to calculate this figure once at mkfs
3505  * time, and store it in the superblock.  If the superblock value is
3506  * present (even for non-bigalloc file systems), we will use it.
3507  */
3508 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3509                           char *buf)
3510 {
3511         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3512         struct ext4_group_desc  *gdp;
3513         ext4_fsblk_t            first_block, last_block, b;
3514         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3515         int                     s, j, count = 0;
3516
3517         if (!ext4_has_feature_bigalloc(sb))
3518                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3519                         sbi->s_itb_per_group + 2);
3520
3521         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3522                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3523         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3524         for (i = 0; i < ngroups; i++) {
3525                 gdp = ext4_get_group_desc(sb, i, NULL);
3526                 b = ext4_block_bitmap(sb, gdp);
3527                 if (b >= first_block && b <= last_block) {
3528                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3529                         count++;
3530                 }
3531                 b = ext4_inode_bitmap(sb, gdp);
3532                 if (b >= first_block && b <= last_block) {
3533                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3534                         count++;
3535                 }
3536                 b = ext4_inode_table(sb, gdp);
3537                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3538                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3539                                 int c = EXT4_B2C(sbi, b - first_block);
3540                                 ext4_set_bit(c, buf);
3541                                 count++;
3542                         }
3543                 if (i != grp)
3544                         continue;
3545                 s = 0;
3546                 if (ext4_bg_has_super(sb, grp)) {
3547                         ext4_set_bit(s++, buf);
3548                         count++;
3549                 }
3550                 j = ext4_bg_num_gdb(sb, grp);
3551                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3552                         ext4_error(sb, "Invalid number of block group "
3553                                    "descriptor blocks: %d", j);
3554                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3555                 }
3556                 count += j;
3557                 for (; j > 0; j--)
3558                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3559         }
3560         if (!count)
3561                 return 0;
3562         return EXT4_CLUSTERS_PER_GROUP(sb) -
3563                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3564 }
3565
3566 /*
3567  * Compute the overhead and stash it in sbi->s_overhead
3568  */
3569 int ext4_calculate_overhead(struct super_block *sb)
3570 {
3571         struct ext4_sb_info *sbi = EXT4_SB(sb);
3572         struct ext4_super_block *es = sbi->s_es;
3573         struct inode *j_inode;
3574         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3575         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3576         ext4_fsblk_t overhead = 0;
3577         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3578
3579         if (!buf)
3580                 return -ENOMEM;
3581
3582         /*
3583          * Compute the overhead (FS structures).  This is constant
3584          * for a given filesystem unless the number of block groups
3585          * changes so we cache the previous value until it does.
3586          */
3587
3588         /*
3589          * All of the blocks before first_data_block are overhead
3590          */
3591         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3592
3593         /*
3594          * Add the overhead found in each block group
3595          */
3596         for (i = 0; i < ngroups; i++) {
3597                 int blks;
3598
3599                 blks = count_overhead(sb, i, buf);
3600                 overhead += blks;
3601                 if (blks)
3602                         memset(buf, 0, PAGE_SIZE);
3603                 cond_resched();
3604         }
3605
3606         /*
3607          * Add the internal journal blocks whether the journal has been
3608          * loaded or not
3609          */
3610         if (sbi->s_journal && !sbi->journal_bdev)
3611                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3612         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3613                 j_inode = ext4_get_journal_inode(sb, j_inum);
3614                 if (j_inode) {
3615                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3616                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3617                         iput(j_inode);
3618                 } else {
3619                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3620                 }
3621         }
3622         sbi->s_overhead = overhead;
3623         smp_wmb();
3624         free_page((unsigned long) buf);
3625         return 0;
3626 }
3627
3628 static void ext4_set_resv_clusters(struct super_block *sb)
3629 {
3630         ext4_fsblk_t resv_clusters;
3631         struct ext4_sb_info *sbi = EXT4_SB(sb);
3632
3633         /*
3634          * There's no need to reserve anything when we aren't using extents.
3635          * The space estimates are exact, there are no unwritten extents,
3636          * hole punching doesn't need new metadata... This is needed especially
3637          * to keep ext2/3 backward compatibility.
3638          */
3639         if (!ext4_has_feature_extents(sb))
3640                 return;
3641         /*
3642          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3643          * This should cover the situations where we can not afford to run
3644          * out of space like for example punch hole, or converting
3645          * unwritten extents in delalloc path. In most cases such
3646          * allocation would require 1, or 2 blocks, higher numbers are
3647          * very rare.
3648          */
3649         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3650                          sbi->s_cluster_bits);
3651
3652         do_div(resv_clusters, 50);
3653         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3654
3655         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3656 }
3657
3658 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3659 {
3660         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3661         char *orig_data = kstrdup(data, GFP_KERNEL);
3662         struct buffer_head *bh, **group_desc;
3663         struct ext4_super_block *es = NULL;
3664         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3665         struct flex_groups **flex_groups;
3666         ext4_fsblk_t block;
3667         ext4_fsblk_t sb_block = get_sb_block(&data);
3668         ext4_fsblk_t logical_sb_block;
3669         unsigned long offset = 0;
3670         unsigned long journal_devnum = 0;
3671         unsigned long def_mount_opts;
3672         struct inode *root;
3673         const char *descr;
3674         int ret = -ENOMEM;
3675         int blocksize, clustersize;
3676         unsigned int db_count;
3677         unsigned int i;
3678         int needs_recovery, has_huge_files, has_bigalloc;
3679         __u64 blocks_count;
3680         int err = 0;
3681         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3682         ext4_group_t first_not_zeroed;
3683
3684         if ((data && !orig_data) || !sbi)
3685                 goto out_free_base;
3686
3687         sbi->s_daxdev = dax_dev;
3688         sbi->s_blockgroup_lock =
3689                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3690         if (!sbi->s_blockgroup_lock)
3691                 goto out_free_base;
3692
3693         sb->s_fs_info = sbi;
3694         sbi->s_sb = sb;
3695         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3696         sbi->s_sb_block = sb_block;
3697         if (sb->s_bdev->bd_part)
3698                 sbi->s_sectors_written_start =
3699                         part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3700
3701         /* Cleanup superblock name */
3702         strreplace(sb->s_id, '/', '!');
3703
3704         /* -EINVAL is default */
3705         ret = -EINVAL;
3706         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3707         if (!blocksize) {
3708                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3709                 goto out_fail;
3710         }
3711
3712         /*
3713          * The ext4 superblock will not be buffer aligned for other than 1kB
3714          * block sizes.  We need to calculate the offset from buffer start.
3715          */
3716         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3717                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3718                 offset = do_div(logical_sb_block, blocksize);
3719         } else {
3720                 logical_sb_block = sb_block;
3721         }
3722
3723         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3724                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3725                 goto out_fail;
3726         }
3727         /*
3728          * Note: s_es must be initialized as soon as possible because
3729          *       some ext4 macro-instructions depend on its value
3730          */
3731         es = (struct ext4_super_block *) (bh->b_data + offset);
3732         sbi->s_es = es;
3733         sb->s_magic = le16_to_cpu(es->s_magic);
3734         if (sb->s_magic != EXT4_SUPER_MAGIC)
3735                 goto cantfind_ext4;
3736         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3737
3738         /* Warn if metadata_csum and gdt_csum are both set. */
3739         if (ext4_has_feature_metadata_csum(sb) &&
3740             ext4_has_feature_gdt_csum(sb))
3741                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3742                              "redundant flags; please run fsck.");
3743
3744         /* Check for a known checksum algorithm */
3745         if (!ext4_verify_csum_type(sb, es)) {
3746                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3747                          "unknown checksum algorithm.");
3748                 silent = 1;
3749                 goto cantfind_ext4;
3750         }
3751
3752         /* Load the checksum driver */
3753         sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3754         if (IS_ERR(sbi->s_chksum_driver)) {
3755                 ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3756                 ret = PTR_ERR(sbi->s_chksum_driver);
3757                 sbi->s_chksum_driver = NULL;
3758                 goto failed_mount;
3759         }
3760
3761         /* Check superblock checksum */
3762         if (!ext4_superblock_csum_verify(sb, es)) {
3763                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3764                          "invalid superblock checksum.  Run e2fsck?");
3765                 silent = 1;
3766                 ret = -EFSBADCRC;
3767                 goto cantfind_ext4;
3768         }
3769
3770         /* Precompute checksum seed for all metadata */
3771         if (ext4_has_feature_csum_seed(sb))
3772                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3773         else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3774                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3775                                                sizeof(es->s_uuid));
3776
3777         /* Set defaults before we parse the mount options */
3778         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3779         set_opt(sb, INIT_INODE_TABLE);
3780         if (def_mount_opts & EXT4_DEFM_DEBUG)
3781                 set_opt(sb, DEBUG);
3782         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3783                 set_opt(sb, GRPID);
3784         if (def_mount_opts & EXT4_DEFM_UID16)
3785                 set_opt(sb, NO_UID32);
3786         /* xattr user namespace & acls are now defaulted on */
3787         set_opt(sb, XATTR_USER);
3788         set_opt(sb, DIOREAD_NOLOCK);
3789 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3790         set_opt(sb, POSIX_ACL);
3791 #endif
3792         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3793         if (ext4_has_metadata_csum(sb))
3794                 set_opt(sb, JOURNAL_CHECKSUM);
3795
3796         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3797                 set_opt(sb, JOURNAL_DATA);
3798         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3799                 set_opt(sb, ORDERED_DATA);
3800         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3801                 set_opt(sb, WRITEBACK_DATA);
3802
3803         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3804                 set_opt(sb, ERRORS_PANIC);
3805         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3806                 set_opt(sb, ERRORS_CONT);
3807         else
3808                 set_opt(sb, ERRORS_RO);
3809         /* block_validity enabled by default; disable with noblock_validity */
3810         set_opt(sb, BLOCK_VALIDITY);
3811         if (def_mount_opts & EXT4_DEFM_DISCARD)
3812                 set_opt(sb, DISCARD);
3813
3814         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3815         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3816         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3817         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3818         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3819
3820         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3821                 set_opt(sb, BARRIER);
3822
3823         /*
3824          * enable delayed allocation by default
3825          * Use -o nodelalloc to turn it off
3826          */
3827         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3828             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3829                 set_opt(sb, DELALLOC);
3830
3831         /*
3832          * set default s_li_wait_mult for lazyinit, for the case there is
3833          * no mount option specified.
3834          */
3835         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3836
3837         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3838         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3839             blocksize > EXT4_MAX_BLOCK_SIZE) {
3840                 ext4_msg(sb, KERN_ERR,
3841                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3842                          blocksize, le32_to_cpu(es->s_log_block_size));
3843                 goto failed_mount;
3844         }
3845
3846         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3847                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3848                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3849         } else {
3850                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3851                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3852                 if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3853                         ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3854                                  sbi->s_first_ino);
3855                         goto failed_mount;
3856                 }
3857                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3858                     (!is_power_of_2(sbi->s_inode_size)) ||
3859                     (sbi->s_inode_size > blocksize)) {
3860                         ext4_msg(sb, KERN_ERR,
3861                                "unsupported inode size: %d",
3862                                sbi->s_inode_size);
3863                         ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
3864                         goto failed_mount;
3865                 }
3866                 /*
3867                  * i_atime_extra is the last extra field available for
3868                  * [acm]times in struct ext4_inode. Checking for that
3869                  * field should suffice to ensure we have extra space
3870                  * for all three.
3871                  */
3872                 if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
3873                         sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
3874                         sb->s_time_gran = 1;
3875                         sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
3876                 } else {
3877                         sb->s_time_gran = NSEC_PER_SEC;
3878                         sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
3879                 }
3880                 sb->s_time_min = EXT4_TIMESTAMP_MIN;
3881         }
3882         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3883                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3884                         EXT4_GOOD_OLD_INODE_SIZE;
3885                 if (ext4_has_feature_extra_isize(sb)) {
3886                         unsigned v, max = (sbi->s_inode_size -
3887                                            EXT4_GOOD_OLD_INODE_SIZE);
3888
3889                         v = le16_to_cpu(es->s_want_extra_isize);
3890                         if (v > max) {
3891                                 ext4_msg(sb, KERN_ERR,
3892                                          "bad s_want_extra_isize: %d", v);
3893                                 goto failed_mount;
3894                         }
3895                         if (sbi->s_want_extra_isize < v)
3896                                 sbi->s_want_extra_isize = v;
3897
3898                         v = le16_to_cpu(es->s_min_extra_isize);
3899                         if (v > max) {
3900                                 ext4_msg(sb, KERN_ERR,
3901                                          "bad s_min_extra_isize: %d", v);
3902                                 goto failed_mount;
3903                         }
3904                         if (sbi->s_want_extra_isize < v)
3905                                 sbi->s_want_extra_isize = v;
3906                 }
3907         }
3908
3909         if (sbi->s_es->s_mount_opts[0]) {
3910                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3911                                               sizeof(sbi->s_es->s_mount_opts),
3912                                               GFP_KERNEL);
3913                 if (!s_mount_opts)
3914                         goto failed_mount;
3915                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3916                                    &journal_ioprio, 0)) {
3917                         ext4_msg(sb, KERN_WARNING,
3918                                  "failed to parse options in superblock: %s",
3919                                  s_mount_opts);
3920                 }
3921                 kfree(s_mount_opts);
3922         }
3923         sbi->s_def_mount_opt = sbi->s_mount_opt;
3924         if (!parse_options((char *) data, sb, &journal_devnum,
3925                            &journal_ioprio, 0))
3926                 goto failed_mount;
3927
3928 #ifdef CONFIG_UNICODE
3929         if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3930                 const struct ext4_sb_encodings *encoding_info;
3931                 struct unicode_map *encoding;
3932                 __u16 encoding_flags;
3933
3934                 if (ext4_has_feature_encrypt(sb)) {
3935                         ext4_msg(sb, KERN_ERR,
3936                                  "Can't mount with encoding and encryption");
3937                         goto failed_mount;
3938                 }
3939
3940                 if (ext4_sb_read_encoding(es, &encoding_info,
3941                                           &encoding_flags)) {
3942                         ext4_msg(sb, KERN_ERR,
3943                                  "Encoding requested by superblock is unknown");
3944                         goto failed_mount;
3945                 }
3946
3947                 encoding = utf8_load(encoding_info->version);
3948                 if (IS_ERR(encoding)) {
3949                         ext4_msg(sb, KERN_ERR,
3950                                  "can't mount with superblock charset: %s-%s "
3951                                  "not supported by the kernel. flags: 0x%x.",
3952                                  encoding_info->name, encoding_info->version,
3953                                  encoding_flags);
3954                         goto failed_mount;
3955                 }
3956                 ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3957                          "%s-%s with flags 0x%hx", encoding_info->name,
3958                          encoding_info->version?:"\b", encoding_flags);
3959
3960                 sbi->s_encoding = encoding;
3961                 sbi->s_encoding_flags = encoding_flags;
3962         }
3963 #endif
3964
3965         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3966                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
3967                 clear_opt(sb, DIOREAD_NOLOCK);
3968                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3969                         ext4_msg(sb, KERN_ERR, "can't mount with "
3970                                  "both data=journal and delalloc");
3971                         goto failed_mount;
3972                 }
3973                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3974                         ext4_msg(sb, KERN_ERR, "can't mount with "
3975                                  "both data=journal and dioread_nolock");
3976                         goto failed_mount;
3977                 }
3978                 if (test_opt(sb, DAX)) {
3979                         ext4_msg(sb, KERN_ERR, "can't mount with "
3980                                  "both data=journal and dax");
3981                         goto failed_mount;
3982                 }
3983                 if (ext4_has_feature_encrypt(sb)) {
3984                         ext4_msg(sb, KERN_WARNING,
3985                                  "encrypted files will use data=ordered "
3986                                  "instead of data journaling mode");
3987                 }
3988                 if (test_opt(sb, DELALLOC))
3989                         clear_opt(sb, DELALLOC);
3990         } else {
3991                 sb->s_iflags |= SB_I_CGROUPWB;
3992         }
3993
3994         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3995                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3996
3997         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3998             (ext4_has_compat_features(sb) ||
3999              ext4_has_ro_compat_features(sb) ||
4000              ext4_has_incompat_features(sb)))
4001                 ext4_msg(sb, KERN_WARNING,
4002                        "feature flags set on rev 0 fs, "
4003                        "running e2fsck is recommended");
4004
4005         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4006                 set_opt2(sb, HURD_COMPAT);
4007                 if (ext4_has_feature_64bit(sb)) {
4008                         ext4_msg(sb, KERN_ERR,
4009                                  "The Hurd can't support 64-bit file systems");
4010                         goto failed_mount;
4011                 }
4012
4013                 /*
4014                  * ea_inode feature uses l_i_version field which is not
4015                  * available in HURD_COMPAT mode.
4016                  */
4017                 if (ext4_has_feature_ea_inode(sb)) {
4018                         ext4_msg(sb, KERN_ERR,
4019                                  "ea_inode feature is not supported for Hurd");
4020                         goto failed_mount;
4021                 }
4022         }
4023
4024         if (IS_EXT2_SB(sb)) {
4025                 if (ext2_feature_set_ok(sb))
4026                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4027                                  "using the ext4 subsystem");
4028                 else {
4029                         /*
4030                          * If we're probing be silent, if this looks like
4031                          * it's actually an ext[34] filesystem.
4032                          */
4033                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4034                                 goto failed_mount;
4035                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4036                                  "to feature incompatibilities");
4037                         goto failed_mount;
4038                 }
4039         }
4040
4041         if (IS_EXT3_SB(sb)) {
4042                 if (ext3_feature_set_ok(sb))
4043                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4044                                  "using the ext4 subsystem");
4045                 else {
4046                         /*
4047                          * If we're probing be silent, if this looks like
4048                          * it's actually an ext4 filesystem.
4049                          */
4050                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4051                                 goto failed_mount;
4052                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4053                                  "to feature incompatibilities");
4054                         goto failed_mount;
4055                 }
4056         }
4057
4058         /*
4059          * Check feature flags regardless of the revision level, since we
4060          * previously didn't change the revision level when setting the flags,
4061          * so there is a chance incompat flags are set on a rev 0 filesystem.
4062          */
4063         if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4064                 goto failed_mount;
4065
4066         if (le32_to_cpu(es->s_log_block_size) >
4067             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4068                 ext4_msg(sb, KERN_ERR,
4069                          "Invalid log block size: %u",
4070                          le32_to_cpu(es->s_log_block_size));
4071                 goto failed_mount;
4072         }
4073         if (le32_to_cpu(es->s_log_cluster_size) >
4074             (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4075                 ext4_msg(sb, KERN_ERR,
4076                          "Invalid log cluster size: %u",
4077                          le32_to_cpu(es->s_log_cluster_size));
4078                 goto failed_mount;
4079         }
4080
4081         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4082                 ext4_msg(sb, KERN_ERR,
4083                          "Number of reserved GDT blocks insanely large: %d",
4084                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4085                 goto failed_mount;
4086         }
4087
4088         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
4089                 if (ext4_has_feature_inline_data(sb)) {
4090                         ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4091                                         " that may contain inline data");
4092                         goto failed_mount;
4093                 }
4094                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
4095                         ext4_msg(sb, KERN_ERR,
4096                                 "DAX unsupported by block device.");
4097                         goto failed_mount;
4098                 }
4099         }
4100
4101         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4102                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4103                          es->s_encryption_level);
4104                 goto failed_mount;
4105         }
4106
4107         if (sb->s_blocksize != blocksize) {
4108                 /* Validate the filesystem blocksize */
4109                 if (!sb_set_blocksize(sb, blocksize)) {
4110                         ext4_msg(sb, KERN_ERR, "bad block size %d",
4111                                         blocksize);
4112                         goto failed_mount;
4113                 }
4114
4115                 brelse(bh);
4116                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4117                 offset = do_div(logical_sb_block, blocksize);
4118                 bh = sb_bread_unmovable(sb, logical_sb_block);
4119                 if (!bh) {
4120                         ext4_msg(sb, KERN_ERR,
4121                                "Can't read superblock on 2nd try");
4122                         goto failed_mount;
4123                 }
4124                 es = (struct ext4_super_block *)(bh->b_data + offset);
4125                 sbi->s_es = es;
4126                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4127                         ext4_msg(sb, KERN_ERR,
4128                                "Magic mismatch, very weird!");
4129                         goto failed_mount;
4130                 }
4131         }
4132
4133         has_huge_files = ext4_has_feature_huge_file(sb);
4134         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4135                                                       has_huge_files);
4136         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4137
4138         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4139         if (ext4_has_feature_64bit(sb)) {
4140                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4141                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4142                     !is_power_of_2(sbi->s_desc_size)) {
4143                         ext4_msg(sb, KERN_ERR,
4144                                "unsupported descriptor size %lu",
4145                                sbi->s_desc_size);
4146                         goto failed_mount;
4147                 }
4148         } else
4149                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4150
4151         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4152         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4153
4154         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4155         if (sbi->s_inodes_per_block == 0)
4156                 goto cantfind_ext4;
4157         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4158             sbi->s_inodes_per_group > blocksize * 8) {
4159                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4160                          sbi->s_blocks_per_group);
4161                 goto failed_mount;
4162         }
4163         sbi->s_itb_per_group = sbi->s_inodes_per_group /
4164                                         sbi->s_inodes_per_block;
4165         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4166         sbi->s_sbh = bh;
4167         sbi->s_mount_state = le16_to_cpu(es->s_state);
4168         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4169         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4170
4171         for (i = 0; i < 4; i++)
4172                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4173         sbi->s_def_hash_version = es->s_def_hash_version;
4174         if (ext4_has_feature_dir_index(sb)) {
4175                 i = le32_to_cpu(es->s_flags);
4176                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
4177                         sbi->s_hash_unsigned = 3;
4178                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4179 #ifdef __CHAR_UNSIGNED__
4180                         if (!sb_rdonly(sb))
4181                                 es->s_flags |=
4182                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4183                         sbi->s_hash_unsigned = 3;
4184 #else
4185                         if (!sb_rdonly(sb))
4186                                 es->s_flags |=
4187                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4188 #endif
4189                 }
4190         }
4191
4192         /* Handle clustersize */
4193         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4194         has_bigalloc = ext4_has_feature_bigalloc(sb);
4195         if (has_bigalloc) {
4196                 if (clustersize < blocksize) {
4197                         ext4_msg(sb, KERN_ERR,
4198                                  "cluster size (%d) smaller than "
4199                                  "block size (%d)", clustersize, blocksize);
4200                         goto failed_mount;
4201                 }
4202                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4203                         le32_to_cpu(es->s_log_block_size);
4204                 sbi->s_clusters_per_group =
4205                         le32_to_cpu(es->s_clusters_per_group);
4206                 if (sbi->s_clusters_per_group > blocksize * 8) {
4207                         ext4_msg(sb, KERN_ERR,
4208                                  "#clusters per group too big: %lu",
4209                                  sbi->s_clusters_per_group);
4210                         goto failed_mount;
4211                 }
4212                 if (sbi->s_blocks_per_group !=
4213                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4214                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4215                                  "clusters per group (%lu) inconsistent",
4216                                  sbi->s_blocks_per_group,
4217                                  sbi->s_clusters_per_group);
4218                         goto failed_mount;
4219                 }
4220         } else {
4221                 if (clustersize != blocksize) {
4222                         ext4_msg(sb, KERN_ERR,
4223                                  "fragment/cluster size (%d) != "
4224                                  "block size (%d)", clustersize, blocksize);
4225                         goto failed_mount;
4226                 }
4227                 if (sbi->s_blocks_per_group > blocksize * 8) {
4228                         ext4_msg(sb, KERN_ERR,
4229                                  "#blocks per group too big: %lu",
4230                                  sbi->s_blocks_per_group);
4231                         goto failed_mount;
4232                 }
4233                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4234                 sbi->s_cluster_bits = 0;
4235         }
4236         sbi->s_cluster_ratio = clustersize / blocksize;
4237
4238         /* Do we have standard group size of clustersize * 8 blocks ? */
4239         if (sbi->s_blocks_per_group == clustersize << 3)
4240                 set_opt2(sb, STD_GROUP_SIZE);
4241
4242         /*
4243          * Test whether we have more sectors than will fit in sector_t,
4244          * and whether the max offset is addressable by the page cache.
4245          */
4246         err = generic_check_addressable(sb->s_blocksize_bits,
4247                                         ext4_blocks_count(es));
4248         if (err) {
4249                 ext4_msg(sb, KERN_ERR, "filesystem"
4250                          " too large to mount safely on this system");
4251                 goto failed_mount;
4252         }
4253
4254         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4255                 goto cantfind_ext4;
4256
4257         /* check blocks count against device size */
4258         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4259         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4260                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4261                        "exceeds size of device (%llu blocks)",
4262                        ext4_blocks_count(es), blocks_count);
4263                 goto failed_mount;
4264         }
4265
4266         /*
4267          * It makes no sense for the first data block to be beyond the end
4268          * of the filesystem.
4269          */
4270         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4271                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4272                          "block %u is beyond end of filesystem (%llu)",
4273                          le32_to_cpu(es->s_first_data_block),
4274                          ext4_blocks_count(es));
4275                 goto failed_mount;
4276         }
4277         if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4278             (sbi->s_cluster_ratio == 1)) {
4279                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4280                          "block is 0 with a 1k block and cluster size");
4281                 goto failed_mount;
4282         }
4283
4284         blocks_count = (ext4_blocks_count(es) -
4285                         le32_to_cpu(es->s_first_data_block) +
4286                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
4287         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4288         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4289                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4290                        "(block count %llu, first data block %u, "
4291                        "blocks per group %lu)", sbi->s_groups_count,
4292                        ext4_blocks_count(es),
4293                        le32_to_cpu(es->s_first_data_block),
4294                        EXT4_BLOCKS_PER_GROUP(sb));
4295                 goto failed_mount;
4296         }
4297         sbi->s_groups_count = blocks_count;
4298         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4299                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4300         if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4301             le32_to_cpu(es->s_inodes_count)) {
4302                 ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4303                          le32_to_cpu(es->s_inodes_count),
4304                          ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4305                 ret = -EINVAL;
4306                 goto failed_mount;
4307         }
4308         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4309                    EXT4_DESC_PER_BLOCK(sb);
4310         if (ext4_has_feature_meta_bg(sb)) {
4311                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4312                         ext4_msg(sb, KERN_WARNING,
4313                                  "first meta block group too large: %u "
4314                                  "(group descriptor block count %u)",
4315                                  le32_to_cpu(es->s_first_meta_bg), db_count);
4316                         goto failed_mount;
4317                 }
4318         }
4319         rcu_assign_pointer(sbi->s_group_desc,
4320                            kvmalloc_array(db_count,
4321                                           sizeof(struct buffer_head *),
4322                                           GFP_KERNEL));
4323         if (sbi->s_group_desc == NULL) {
4324                 ext4_msg(sb, KERN_ERR, "not enough memory");
4325                 ret = -ENOMEM;
4326                 goto failed_mount;
4327         }
4328
4329         bgl_lock_init(sbi->s_blockgroup_lock);
4330
4331         /* Pre-read the descriptors into the buffer cache */
4332         for (i = 0; i < db_count; i++) {
4333                 block = descriptor_loc(sb, logical_sb_block, i);
4334                 sb_breadahead(sb, block);
4335         }
4336
4337         for (i = 0; i < db_count; i++) {
4338                 struct buffer_head *bh;
4339
4340                 block = descriptor_loc(sb, logical_sb_block, i);
4341                 bh = sb_bread_unmovable(sb, block);
4342                 if (!bh) {
4343                         ext4_msg(sb, KERN_ERR,
4344                                "can't read group descriptor %d", i);
4345                         db_count = i;
4346                         goto failed_mount2;
4347                 }
4348                 rcu_read_lock();
4349                 rcu_dereference(sbi->s_group_desc)[i] = bh;
4350                 rcu_read_unlock();
4351         }
4352         sbi->s_gdb_count = db_count;
4353         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4354                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4355                 ret = -EFSCORRUPTED;
4356                 goto failed_mount2;
4357         }
4358
4359         timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4360
4361         /* Register extent status tree shrinker */
4362         if (ext4_es_register_shrinker(sbi))
4363                 goto failed_mount3;
4364
4365         sbi->s_stripe = ext4_get_stripe_size(sbi);
4366         sbi->s_extent_max_zeroout_kb = 32;
4367
4368         /*
4369          * set up enough so that it can read an inode
4370          */
4371         sb->s_op = &ext4_sops;
4372         sb->s_export_op = &ext4_export_ops;
4373         sb->s_xattr = ext4_xattr_handlers;
4374 #ifdef CONFIG_FS_ENCRYPTION
4375         sb->s_cop = &ext4_cryptops;
4376 #endif
4377 #ifdef CONFIG_FS_VERITY
4378         sb->s_vop = &ext4_verityops;
4379 #endif
4380 #ifdef CONFIG_QUOTA
4381         sb->dq_op = &ext4_quota_operations;
4382         if (ext4_has_feature_quota(sb))
4383                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
4384         else
4385                 sb->s_qcop = &ext4_qctl_operations;
4386         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4387 #endif
4388         memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4389
4390         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4391         mutex_init(&sbi->s_orphan_lock);
4392
4393         sb->s_root = NULL;
4394
4395         needs_recovery = (es->s_last_orphan != 0 ||
4396                           ext4_has_feature_journal_needs_recovery(sb));
4397
4398         if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4399                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4400                         goto failed_mount3a;
4401
4402         /*
4403          * The first inode we look at is the journal inode.  Don't try
4404          * root first: it may be modified in the journal!
4405          */
4406         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4407                 err = ext4_load_journal(sb, es, journal_devnum);
4408                 if (err)
4409                         goto failed_mount3a;
4410         } else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4411                    ext4_has_feature_journal_needs_recovery(sb)) {
4412                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4413                        "suppressed and not mounted read-only");
4414                 goto failed_mount_wq;
4415         } else {
4416                 /* Nojournal mode, all journal mount options are illegal */
4417                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4418                         ext4_msg(sb, KERN_ERR, "can't mount with "
4419                                  "journal_checksum, fs mounted w/o journal");
4420                         goto failed_mount_wq;
4421                 }
4422                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4423                         ext4_msg(sb, KERN_ERR, "can't mount with "
4424                                  "journal_async_commit, fs mounted w/o journal");
4425                         goto failed_mount_wq;
4426                 }
4427                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4428                         ext4_msg(sb, KERN_ERR, "can't mount with "
4429                                  "commit=%lu, fs mounted w/o journal",
4430                                  sbi->s_commit_interval / HZ);
4431                         goto failed_mount_wq;
4432                 }
4433                 if (EXT4_MOUNT_DATA_FLAGS &
4434                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4435                         ext4_msg(sb, KERN_ERR, "can't mount with "
4436                                  "data=, fs mounted w/o journal");
4437                         goto failed_mount_wq;
4438                 }
4439                 sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4440                 clear_opt(sb, JOURNAL_CHECKSUM);
4441                 clear_opt(sb, DATA_FLAGS);
4442                 sbi->s_journal = NULL;
4443                 needs_recovery = 0;
4444                 goto no_journal;
4445         }
4446
4447         if (ext4_has_feature_64bit(sb) &&
4448             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4449                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4450                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4451                 goto failed_mount_wq;
4452         }
4453
4454         if (!set_journal_csum_feature_set(sb)) {
4455                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4456                          "feature set");
4457                 goto failed_mount_wq;
4458         }
4459
4460         /* We have now updated the journal if required, so we can
4461          * validate the data journaling mode. */
4462         switch (test_opt(sb, DATA_FLAGS)) {
4463         case 0:
4464                 /* No mode set, assume a default based on the journal
4465                  * capabilities: ORDERED_DATA if the journal can
4466                  * cope, else JOURNAL_DATA
4467                  */
4468                 if (jbd2_journal_check_available_features
4469                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4470                         set_opt(sb, ORDERED_DATA);
4471                         sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4472                 } else {
4473                         set_opt(sb, JOURNAL_DATA);
4474                         sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4475                 }
4476                 break;
4477
4478         case EXT4_MOUNT_ORDERED_DATA:
4479         case EXT4_MOUNT_WRITEBACK_DATA:
4480                 if (!jbd2_journal_check_available_features
4481                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4482                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4483                                "requested data journaling mode");
4484                         goto failed_mount_wq;
4485                 }
4486         default:
4487                 break;
4488         }
4489
4490         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4491             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4492                 ext4_msg(sb, KERN_ERR, "can't mount with "
4493                         "journal_async_commit in data=ordered mode");
4494                 goto failed_mount_wq;
4495         }
4496
4497         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4498
4499         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4500
4501 no_journal:
4502         if (!test_opt(sb, NO_MBCACHE)) {
4503                 sbi->s_ea_block_cache = ext4_xattr_create_cache();
4504                 if (!sbi->s_ea_block_cache) {
4505                         ext4_msg(sb, KERN_ERR,
4506                                  "Failed to create ea_block_cache");
4507                         goto failed_mount_wq;
4508                 }
4509
4510                 if (ext4_has_feature_ea_inode(sb)) {
4511                         sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4512                         if (!sbi->s_ea_inode_cache) {
4513                                 ext4_msg(sb, KERN_ERR,
4514                                          "Failed to create ea_inode_cache");
4515                                 goto failed_mount_wq;
4516                         }
4517                 }
4518         }
4519
4520         if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4521                 ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4522                 goto failed_mount_wq;
4523         }
4524
4525         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4526             !ext4_has_feature_encrypt(sb)) {
4527                 ext4_set_feature_encrypt(sb);
4528                 ext4_commit_super(sb, 1);
4529         }
4530
4531         /*
4532          * Get the # of file system overhead blocks from the
4533          * superblock if present.
4534          */
4535         if (es->s_overhead_clusters)
4536                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4537         else {
4538                 err = ext4_calculate_overhead(sb);
4539                 if (err)
4540                         goto failed_mount_wq;
4541         }
4542
4543         /*
4544          * The maximum number of concurrent works can be high and
4545          * concurrency isn't really necessary.  Limit it to 1.
4546          */
4547         EXT4_SB(sb)->rsv_conversion_wq =
4548                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4549         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4550                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4551                 ret = -ENOMEM;
4552                 goto failed_mount4;
4553         }
4554
4555         /*
4556          * The jbd2_journal_load will have done any necessary log recovery,
4557          * so we can safely mount the rest of the filesystem now.
4558          */
4559
4560         root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4561         if (IS_ERR(root)) {
4562                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4563                 ret = PTR_ERR(root);
4564                 root = NULL;
4565                 goto failed_mount4;
4566         }
4567         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4568                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4569                 iput(root);
4570                 goto failed_mount4;
4571         }
4572
4573 #ifdef CONFIG_UNICODE
4574         if (sbi->s_encoding)
4575                 sb->s_d_op = &ext4_dentry_ops;
4576 #endif
4577
4578         sb->s_root = d_make_root(root);
4579         if (!sb->s_root) {
4580                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4581                 ret = -ENOMEM;
4582                 goto failed_mount4;
4583         }
4584
4585         ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4586         if (ret == -EROFS) {
4587                 sb->s_flags |= SB_RDONLY;
4588                 ret = 0;
4589         } else if (ret)
4590                 goto failed_mount4a;
4591
4592         ext4_set_resv_clusters(sb);
4593
4594         err = ext4_setup_system_zone(sb);
4595         if (err) {
4596                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4597                          "zone (%d)", err);
4598                 goto failed_mount4a;
4599         }
4600
4601         ext4_ext_init(sb);
4602         err = ext4_mb_init(sb);
4603         if (err) {
4604                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4605                          err);
4606                 goto failed_mount5;
4607         }
4608
4609         block = ext4_count_free_clusters(sb);
4610         ext4_free_blocks_count_set(sbi->s_es,
4611                                    EXT4_C2B(sbi, block));
4612         ext4_superblock_csum_set(sb);
4613         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4614                                   GFP_KERNEL);
4615         if (!err) {
4616                 unsigned long freei = ext4_count_free_inodes(sb);
4617                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4618                 ext4_superblock_csum_set(sb);
4619                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4620                                           GFP_KERNEL);
4621         }
4622         if (!err)
4623                 err = percpu_counter_init(&sbi->s_dirs_counter,
4624                                           ext4_count_dirs(sb), GFP_KERNEL);
4625         if (!err)
4626                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4627                                           GFP_KERNEL);
4628         if (!err)
4629                 err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
4630
4631         if (err) {
4632                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4633                 goto failed_mount6;
4634         }
4635
4636         if (ext4_has_feature_flex_bg(sb))
4637                 if (!ext4_fill_flex_info(sb)) {
4638                         ext4_msg(sb, KERN_ERR,
4639                                "unable to initialize "
4640                                "flex_bg meta info!");
4641                         goto failed_mount6;
4642                 }
4643
4644         err = ext4_register_li_request(sb, first_not_zeroed);
4645         if (err)
4646                 goto failed_mount6;
4647
4648         err = ext4_register_sysfs(sb);
4649         if (err)
4650                 goto failed_mount7;
4651
4652 #ifdef CONFIG_QUOTA
4653         /* Enable quota usage during mount. */
4654         if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4655                 err = ext4_enable_quotas(sb);
4656                 if (err)
4657                         goto failed_mount8;
4658         }
4659 #endif  /* CONFIG_QUOTA */
4660
4661         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4662         ext4_orphan_cleanup(sb, es);
4663         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4664         if (needs_recovery) {
4665                 ext4_msg(sb, KERN_INFO, "recovery complete");
4666                 ext4_mark_recovery_complete(sb, es);
4667         }
4668         if (EXT4_SB(sb)->s_journal) {
4669                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4670                         descr = " journalled data mode";
4671                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4672                         descr = " ordered data mode";
4673                 else
4674                         descr = " writeback data mode";
4675         } else
4676                 descr = "out journal";
4677
4678         if (test_opt(sb, DISCARD)) {
4679                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4680                 if (!blk_queue_discard(q))
4681                         ext4_msg(sb, KERN_WARNING,
4682                                  "mounting with \"discard\" option, but "
4683                                  "the device does not support discard");
4684         }
4685
4686         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4687                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4688                          "Opts: %.*s%s%s", descr,
4689                          (int) sizeof(sbi->s_es->s_mount_opts),
4690                          sbi->s_es->s_mount_opts,
4691                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4692
4693         if (es->s_error_count)
4694                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4695
4696         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4697         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4698         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4699         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4700
4701         kfree(orig_data);
4702         return 0;
4703
4704 cantfind_ext4:
4705         if (!silent)
4706                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4707         goto failed_mount;
4708
4709 #ifdef CONFIG_QUOTA
4710 failed_mount8:
4711         ext4_unregister_sysfs(sb);
4712 #endif
4713 failed_mount7:
4714         ext4_unregister_li_request(sb);
4715 failed_mount6:
4716         ext4_mb_release(sb);
4717         rcu_read_lock();
4718         flex_groups = rcu_dereference(sbi->s_flex_groups);
4719         if (flex_groups) {
4720                 for (i = 0; i < sbi->s_flex_groups_allocated; i++)
4721                         kvfree(flex_groups[i]);
4722                 kvfree(flex_groups);
4723         }
4724         rcu_read_unlock();
4725         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4726         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4727         percpu_counter_destroy(&sbi->s_dirs_counter);
4728         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4729         percpu_free_rwsem(&sbi->s_writepages_rwsem);
4730 failed_mount5:
4731         ext4_ext_release(sb);
4732         ext4_release_system_zone(sb);
4733 failed_mount4a:
4734         dput(sb->s_root);
4735         sb->s_root = NULL;
4736 failed_mount4:
4737         ext4_msg(sb, KERN_ERR, "mount failed");
4738         if (EXT4_SB(sb)->rsv_conversion_wq)
4739                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4740 failed_mount_wq:
4741         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4742         sbi->s_ea_inode_cache = NULL;
4743
4744         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4745         sbi->s_ea_block_cache = NULL;
4746
4747         if (sbi->s_journal) {
4748                 jbd2_journal_destroy(sbi->s_journal);
4749                 sbi->s_journal = NULL;
4750         }
4751 failed_mount3a:
4752         ext4_es_unregister_shrinker(sbi);
4753 failed_mount3:
4754         del_timer_sync(&sbi->s_err_report);
4755         if (sbi->s_mmp_tsk)
4756                 kthread_stop(sbi->s_mmp_tsk);
4757 failed_mount2:
4758         rcu_read_lock();
4759         group_desc = rcu_dereference(sbi->s_group_desc);
4760         for (i = 0; i < db_count; i++)
4761                 brelse(group_desc[i]);
4762         kvfree(group_desc);
4763         rcu_read_unlock();
4764 failed_mount:
4765         if (sbi->s_chksum_driver)
4766                 crypto_free_shash(sbi->s_chksum_driver);
4767
4768 #ifdef CONFIG_UNICODE
4769         utf8_unload(sbi->s_encoding);
4770 #endif
4771
4772 #ifdef CONFIG_QUOTA
4773         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4774                 kfree(get_qf_name(sb, sbi, i));
4775 #endif
4776         ext4_blkdev_remove(sbi);
4777         brelse(bh);
4778 out_fail:
4779         sb->s_fs_info = NULL;
4780         kfree(sbi->s_blockgroup_lock);
4781 out_free_base:
4782         kfree(sbi);
4783         kfree(orig_data);
4784         fs_put_dax(dax_dev);
4785         return err ? err : ret;
4786 }
4787
4788 /*
4789  * Setup any per-fs journal parameters now.  We'll do this both on
4790  * initial mount, once the journal has been initialised but before we've
4791  * done any recovery; and again on any subsequent remount.
4792  */
4793 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4794 {
4795         struct ext4_sb_info *sbi = EXT4_SB(sb);
4796
4797         journal->j_commit_interval = sbi->s_commit_interval;
4798         journal->j_min_batch_time = sbi->s_min_batch_time;
4799         journal->j_max_batch_time = sbi->s_max_batch_time;
4800
4801         write_lock(&journal->j_state_lock);
4802         if (test_opt(sb, BARRIER))
4803                 journal->j_flags |= JBD2_BARRIER;
4804         else
4805                 journal->j_flags &= ~JBD2_BARRIER;
4806         if (test_opt(sb, DATA_ERR_ABORT))
4807                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4808         else
4809                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4810         write_unlock(&journal->j_state_lock);
4811 }
4812
4813 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4814                                              unsigned int journal_inum)
4815 {
4816         struct inode *journal_inode;
4817
4818         /*
4819          * Test for the existence of a valid inode on disk.  Bad things
4820          * happen if we iget() an unused inode, as the subsequent iput()
4821          * will try to delete it.
4822          */
4823         journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4824         if (IS_ERR(journal_inode)) {
4825                 ext4_msg(sb, KERN_ERR, "no journal found");
4826                 return NULL;
4827         }
4828         if (!journal_inode->i_nlink) {
4829                 make_bad_inode(journal_inode);
4830                 iput(journal_inode);
4831                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4832                 return NULL;
4833         }
4834
4835         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4836                   journal_inode, journal_inode->i_size);
4837         if (!S_ISREG(journal_inode->i_mode)) {
4838                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4839                 iput(journal_inode);
4840                 return NULL;
4841         }
4842         return journal_inode;
4843 }
4844
4845 static journal_t *ext4_get_journal(struct super_block *sb,
4846                                    unsigned int journal_inum)
4847 {
4848         struct inode *journal_inode;
4849         journal_t *journal;
4850
4851         BUG_ON(!ext4_has_feature_journal(sb));
4852
4853         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4854         if (!journal_inode)
4855                 return NULL;
4856
4857         journal = jbd2_journal_init_inode(journal_inode);
4858         if (!journal) {
4859                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4860                 iput(journal_inode);
4861                 return NULL;
4862         }
4863         journal->j_private = sb;
4864         ext4_init_journal_params(sb, journal);
4865         return journal;
4866 }
4867
4868 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4869                                        dev_t j_dev)
4870 {
4871         struct buffer_head *bh;
4872         journal_t *journal;
4873         ext4_fsblk_t start;
4874         ext4_fsblk_t len;
4875         int hblock, blocksize;
4876         ext4_fsblk_t sb_block;
4877         unsigned long offset;
4878         struct ext4_super_block *es;
4879         struct block_device *bdev;
4880
4881         BUG_ON(!ext4_has_feature_journal(sb));
4882
4883         bdev = ext4_blkdev_get(j_dev, sb);
4884         if (bdev == NULL)
4885                 return NULL;
4886
4887         blocksize = sb->s_blocksize;
4888         hblock = bdev_logical_block_size(bdev);
4889         if (blocksize < hblock) {
4890                 ext4_msg(sb, KERN_ERR,
4891                         "blocksize too small for journal device");
4892                 goto out_bdev;
4893         }
4894
4895         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4896         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4897         set_blocksize(bdev, blocksize);
4898         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4899                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4900                        "external journal");
4901                 goto out_bdev;
4902         }
4903
4904         es = (struct ext4_super_block *) (bh->b_data + offset);
4905         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4906             !(le32_to_cpu(es->s_feature_incompat) &
4907               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4908                 ext4_msg(sb, KERN_ERR, "external journal has "
4909                                         "bad superblock");
4910                 brelse(bh);
4911                 goto out_bdev;
4912         }
4913
4914         if ((le32_to_cpu(es->s_feature_ro_compat) &
4915              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4916             es->s_checksum != ext4_superblock_csum(sb, es)) {
4917                 ext4_msg(sb, KERN_ERR, "external journal has "
4918                                        "corrupt superblock");
4919                 brelse(bh);
4920                 goto out_bdev;
4921         }
4922
4923         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4924                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4925                 brelse(bh);
4926                 goto out_bdev;
4927         }
4928
4929         len = ext4_blocks_count(es);
4930         start = sb_block + 1;
4931         brelse(bh);     /* we're done with the superblock */
4932
4933         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4934                                         start, len, blocksize);
4935         if (!journal) {
4936                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4937                 goto out_bdev;
4938         }
4939         journal->j_private = sb;
4940         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4941         wait_on_buffer(journal->j_sb_buffer);
4942         if (!buffer_uptodate(journal->j_sb_buffer)) {
4943                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4944                 goto out_journal;
4945         }
4946         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4947                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4948                                         "user (unsupported) - %d",
4949                         be32_to_cpu(journal->j_superblock->s_nr_users));
4950                 goto out_journal;
4951         }
4952         EXT4_SB(sb)->journal_bdev = bdev;
4953         ext4_init_journal_params(sb, journal);
4954         return journal;
4955
4956 out_journal:
4957         jbd2_journal_destroy(journal);
4958 out_bdev:
4959         ext4_blkdev_put(bdev);
4960         return NULL;
4961 }
4962
4963 static int ext4_load_journal(struct super_block *sb,
4964                              struct ext4_super_block *es,
4965                              unsigned long journal_devnum)
4966 {
4967         journal_t *journal;
4968         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4969         dev_t journal_dev;
4970         int err = 0;
4971         int really_read_only;
4972
4973         BUG_ON(!ext4_has_feature_journal(sb));
4974
4975         if (journal_devnum &&
4976             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4977                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4978                         "numbers have changed");
4979                 journal_dev = new_decode_dev(journal_devnum);
4980         } else
4981                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4982
4983         really_read_only = bdev_read_only(sb->s_bdev);
4984
4985         /*
4986          * Are we loading a blank journal or performing recovery after a
4987          * crash?  For recovery, we need to check in advance whether we
4988          * can get read-write access to the device.
4989          */
4990         if (ext4_has_feature_journal_needs_recovery(sb)) {
4991                 if (sb_rdonly(sb)) {
4992                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4993                                         "required on readonly filesystem");
4994                         if (really_read_only) {
4995                                 ext4_msg(sb, KERN_ERR, "write access "
4996                                         "unavailable, cannot proceed "
4997                                         "(try mounting with noload)");
4998                                 return -EROFS;
4999                         }
5000                         ext4_msg(sb, KERN_INFO, "write access will "
5001                                "be enabled during recovery");
5002                 }
5003         }
5004
5005         if (journal_inum && journal_dev) {
5006                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
5007                        "and inode journals!");
5008                 return -EINVAL;
5009         }
5010
5011         if (journal_inum) {
5012                 if (!(journal = ext4_get_journal(sb, journal_inum)))
5013                         return -EINVAL;
5014         } else {
5015                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
5016                         return -EINVAL;
5017         }
5018
5019         if (!(journal->j_flags & JBD2_BARRIER))
5020                 ext4_msg(sb, KERN_INFO, "barriers disabled");
5021
5022         if (!ext4_has_feature_journal_needs_recovery(sb))
5023                 err = jbd2_journal_wipe(journal, !really_read_only);
5024         if (!err) {
5025                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5026                 if (save)
5027                         memcpy(save, ((char *) es) +
5028                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5029                 err = jbd2_journal_load(journal);
5030                 if (save)
5031                         memcpy(((char *) es) + EXT4_S_ERR_START,
5032                                save, EXT4_S_ERR_LEN);
5033                 kfree(save);
5034         }
5035
5036         if (err) {
5037                 ext4_msg(sb, KERN_ERR, "error loading journal");
5038                 jbd2_journal_destroy(journal);
5039                 return err;
5040         }
5041
5042         EXT4_SB(sb)->s_journal = journal;
5043         ext4_clear_journal_err(sb, es);
5044
5045         if (!really_read_only && journal_devnum &&
5046             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5047                 es->s_journal_dev = cpu_to_le32(journal_devnum);
5048
5049                 /* Make sure we flush the recovery flag to disk. */
5050                 ext4_commit_super(sb, 1);
5051         }
5052
5053         return 0;
5054 }
5055
5056 static int ext4_commit_super(struct super_block *sb, int sync)
5057 {
5058         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5059         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5060         int error = 0;
5061
5062         if (!sbh || block_device_ejected(sb))
5063                 return error;
5064
5065         /*
5066          * The superblock bh should be mapped, but it might not be if the
5067          * device was hot-removed. Not much we can do but fail the I/O.
5068          */
5069         if (!buffer_mapped(sbh))
5070                 return error;
5071
5072         /*
5073          * If the file system is mounted read-only, don't update the
5074          * superblock write time.  This avoids updating the superblock
5075          * write time when we are mounting the root file system
5076          * read/only but we need to replay the journal; at that point,
5077          * for people who are east of GMT and who make their clock
5078          * tick in localtime for Windows bug-for-bug compatibility,
5079          * the clock is set in the future, and this will cause e2fsck
5080          * to complain and force a full file system check.
5081          */
5082         if (!(sb->s_flags & SB_RDONLY))
5083                 ext4_update_tstamp(es, s_wtime);
5084         if (sb->s_bdev->bd_part)
5085                 es->s_kbytes_written =
5086                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5087                             ((part_stat_read(sb->s_bdev->bd_part,
5088                                              sectors[STAT_WRITE]) -
5089                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
5090         else
5091                 es->s_kbytes_written =
5092                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5093         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5094                 ext4_free_blocks_count_set(es,
5095                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5096                                 &EXT4_SB(sb)->s_freeclusters_counter)));
5097         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5098                 es->s_free_inodes_count =
5099                         cpu_to_le32(percpu_counter_sum_positive(
5100                                 &EXT4_SB(sb)->s_freeinodes_counter));
5101         BUFFER_TRACE(sbh, "marking dirty");
5102         ext4_superblock_csum_set(sb);
5103         if (sync)
5104                 lock_buffer(sbh);
5105         if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5106                 /*
5107                  * Oh, dear.  A previous attempt to write the
5108                  * superblock failed.  This could happen because the
5109                  * USB device was yanked out.  Or it could happen to
5110                  * be a transient write error and maybe the block will
5111                  * be remapped.  Nothing we can do but to retry the
5112                  * write and hope for the best.
5113                  */
5114                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
5115                        "superblock detected");
5116                 clear_buffer_write_io_error(sbh);
5117                 set_buffer_uptodate(sbh);
5118         }
5119         mark_buffer_dirty(sbh);
5120         if (sync) {
5121                 unlock_buffer(sbh);
5122                 error = __sync_dirty_buffer(sbh,
5123                         REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5124                 if (buffer_write_io_error(sbh)) {
5125                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
5126                                "superblock");
5127                         clear_buffer_write_io_error(sbh);
5128                         set_buffer_uptodate(sbh);
5129                 }
5130         }
5131         return error;
5132 }
5133
5134 /*
5135  * Have we just finished recovery?  If so, and if we are mounting (or
5136  * remounting) the filesystem readonly, then we will end up with a
5137  * consistent fs on disk.  Record that fact.
5138  */
5139 static void ext4_mark_recovery_complete(struct super_block *sb,
5140                                         struct ext4_super_block *es)
5141 {
5142         journal_t *journal = EXT4_SB(sb)->s_journal;
5143
5144         if (!ext4_has_feature_journal(sb)) {
5145                 BUG_ON(journal != NULL);
5146                 return;
5147         }
5148         jbd2_journal_lock_updates(journal);
5149         if (jbd2_journal_flush(journal) < 0)
5150                 goto out;
5151
5152         if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5153                 ext4_clear_feature_journal_needs_recovery(sb);
5154                 ext4_commit_super(sb, 1);
5155         }
5156
5157 out:
5158         jbd2_journal_unlock_updates(journal);
5159 }
5160
5161 /*
5162  * If we are mounting (or read-write remounting) a filesystem whose journal
5163  * has recorded an error from a previous lifetime, move that error to the
5164  * main filesystem now.
5165  */
5166 static void ext4_clear_journal_err(struct super_block *sb,
5167                                    struct ext4_super_block *es)
5168 {
5169         journal_t *journal;
5170         int j_errno;
5171         const char *errstr;
5172
5173         BUG_ON(!ext4_has_feature_journal(sb));
5174
5175         journal = EXT4_SB(sb)->s_journal;
5176
5177         /*
5178          * Now check for any error status which may have been recorded in the
5179          * journal by a prior ext4_error() or ext4_abort()
5180          */
5181
5182         j_errno = jbd2_journal_errno(journal);
5183         if (j_errno) {
5184                 char nbuf[16];
5185
5186                 errstr = ext4_decode_error(sb, j_errno, nbuf);
5187                 ext4_warning(sb, "Filesystem error recorded "
5188                              "from previous mount: %s", errstr);
5189                 ext4_warning(sb, "Marking fs in need of filesystem check.");
5190
5191                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5192                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5193                 ext4_commit_super(sb, 1);
5194
5195                 jbd2_journal_clear_err(journal);
5196                 jbd2_journal_update_sb_errno(journal);
5197         }
5198 }
5199
5200 /*
5201  * Force the running and committing transactions to commit,
5202  * and wait on the commit.
5203  */
5204 int ext4_force_commit(struct super_block *sb)
5205 {
5206         journal_t *journal;
5207
5208         if (sb_rdonly(sb))
5209                 return 0;
5210
5211         journal = EXT4_SB(sb)->s_journal;
5212         return ext4_journal_force_commit(journal);
5213 }
5214
5215 static int ext4_sync_fs(struct super_block *sb, int wait)
5216 {
5217         int ret = 0;
5218         tid_t target;
5219         bool needs_barrier = false;
5220         struct ext4_sb_info *sbi = EXT4_SB(sb);
5221
5222         if (unlikely(ext4_forced_shutdown(sbi)))
5223                 return 0;
5224
5225         trace_ext4_sync_fs(sb, wait);
5226         flush_workqueue(sbi->rsv_conversion_wq);
5227         /*
5228          * Writeback quota in non-journalled quota case - journalled quota has
5229          * no dirty dquots
5230          */
5231         dquot_writeback_dquots(sb, -1);
5232         /*
5233          * Data writeback is possible w/o journal transaction, so barrier must
5234          * being sent at the end of the function. But we can skip it if
5235          * transaction_commit will do it for us.
5236          */
5237         if (sbi->s_journal) {
5238                 target = jbd2_get_latest_transaction(sbi->s_journal);
5239                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5240                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5241                         needs_barrier = true;
5242
5243                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5244                         if (wait)
5245                                 ret = jbd2_log_wait_commit(sbi->s_journal,
5246                                                            target);
5247                 }
5248         } else if (wait && test_opt(sb, BARRIER))
5249                 needs_barrier = true;
5250         if (needs_barrier) {
5251                 int err;
5252                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5253                 if (!ret)
5254                         ret = err;
5255         }
5256
5257         return ret;
5258 }
5259
5260 /*
5261  * LVM calls this function before a (read-only) snapshot is created.  This
5262  * gives us a chance to flush the journal completely and mark the fs clean.
5263  *
5264  * Note that only this function cannot bring a filesystem to be in a clean
5265  * state independently. It relies on upper layer to stop all data & metadata
5266  * modifications.
5267  */
5268 static int ext4_freeze(struct super_block *sb)
5269 {
5270         int error = 0;
5271         journal_t *journal;
5272
5273         if (sb_rdonly(sb))
5274                 return 0;
5275
5276         journal = EXT4_SB(sb)->s_journal;
5277
5278         if (journal) {
5279                 /* Now we set up the journal barrier. */
5280                 jbd2_journal_lock_updates(journal);
5281
5282                 /*
5283                  * Don't clear the needs_recovery flag if we failed to
5284                  * flush the journal.
5285                  */
5286                 error = jbd2_journal_flush(journal);
5287                 if (error < 0)
5288                         goto out;
5289
5290                 /* Journal blocked and flushed, clear needs_recovery flag. */
5291                 ext4_clear_feature_journal_needs_recovery(sb);
5292         }
5293
5294         error = ext4_commit_super(sb, 1);
5295 out:
5296         if (journal)
5297                 /* we rely on upper layer to stop further updates */
5298                 jbd2_journal_unlock_updates(journal);
5299         return error;
5300 }
5301
5302 /*
5303  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5304  * flag here, even though the filesystem is not technically dirty yet.
5305  */
5306 static int ext4_unfreeze(struct super_block *sb)
5307 {
5308         if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5309                 return 0;
5310
5311         if (EXT4_SB(sb)->s_journal) {
5312                 /* Reset the needs_recovery flag before the fs is unlocked. */
5313                 ext4_set_feature_journal_needs_recovery(sb);
5314         }
5315
5316         ext4_commit_super(sb, 1);
5317         return 0;
5318 }
5319
5320 /*
5321  * Structure to save mount options for ext4_remount's benefit
5322  */
5323 struct ext4_mount_options {
5324         unsigned long s_mount_opt;
5325         unsigned long s_mount_opt2;
5326         kuid_t s_resuid;
5327         kgid_t s_resgid;
5328         unsigned long s_commit_interval;
5329         u32 s_min_batch_time, s_max_batch_time;
5330 #ifdef CONFIG_QUOTA
5331         int s_jquota_fmt;
5332         char *s_qf_names[EXT4_MAXQUOTAS];
5333 #endif
5334 };
5335
5336 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5337 {
5338         struct ext4_super_block *es;
5339         struct ext4_sb_info *sbi = EXT4_SB(sb);
5340         unsigned long old_sb_flags;
5341         struct ext4_mount_options old_opts;
5342         int enable_quota = 0;
5343         ext4_group_t g;
5344         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5345         int err = 0;
5346 #ifdef CONFIG_QUOTA
5347         int i, j;
5348         char *to_free[EXT4_MAXQUOTAS];
5349 #endif
5350         char *orig_data = kstrdup(data, GFP_KERNEL);
5351
5352         if (data && !orig_data)
5353                 return -ENOMEM;
5354
5355         /* Store the original options */
5356         old_sb_flags = sb->s_flags;
5357         old_opts.s_mount_opt = sbi->s_mount_opt;
5358         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5359         old_opts.s_resuid = sbi->s_resuid;
5360         old_opts.s_resgid = sbi->s_resgid;
5361         old_opts.s_commit_interval = sbi->s_commit_interval;
5362         old_opts.s_min_batch_time = sbi->s_min_batch_time;
5363         old_opts.s_max_batch_time = sbi->s_max_batch_time;
5364 #ifdef CONFIG_QUOTA
5365         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5366         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5367                 if (sbi->s_qf_names[i]) {
5368                         char *qf_name = get_qf_name(sb, sbi, i);
5369
5370                         old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5371                         if (!old_opts.s_qf_names[i]) {
5372                                 for (j = 0; j < i; j++)
5373                                         kfree(old_opts.s_qf_names[j]);
5374                                 kfree(orig_data);
5375                                 return -ENOMEM;
5376                         }
5377                 } else
5378                         old_opts.s_qf_names[i] = NULL;
5379 #endif
5380         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5381                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5382
5383         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5384                 err = -EINVAL;
5385                 goto restore_opts;
5386         }
5387
5388         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5389             test_opt(sb, JOURNAL_CHECKSUM)) {
5390                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5391                          "during remount not supported; ignoring");
5392                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5393         }
5394
5395         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5396                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5397                         ext4_msg(sb, KERN_ERR, "can't mount with "
5398                                  "both data=journal and delalloc");
5399                         err = -EINVAL;
5400                         goto restore_opts;
5401                 }
5402                 if (test_opt(sb, DIOREAD_NOLOCK)) {
5403                         ext4_msg(sb, KERN_ERR, "can't mount with "
5404                                  "both data=journal and dioread_nolock");
5405                         err = -EINVAL;
5406                         goto restore_opts;
5407                 }
5408                 if (test_opt(sb, DAX)) {
5409                         ext4_msg(sb, KERN_ERR, "can't mount with "
5410                                  "both data=journal and dax");
5411                         err = -EINVAL;
5412                         goto restore_opts;
5413                 }
5414         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5415                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5416                         ext4_msg(sb, KERN_ERR, "can't mount with "
5417                                 "journal_async_commit in data=ordered mode");
5418                         err = -EINVAL;
5419                         goto restore_opts;
5420                 }
5421         }
5422
5423         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5424                 ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5425                 err = -EINVAL;
5426                 goto restore_opts;
5427         }
5428
5429         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5430                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5431                         "dax flag with busy inodes while remounting");
5432                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5433         }
5434
5435         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5436                 ext4_abort(sb, "Abort forced by user");
5437
5438         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5439                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5440
5441         es = sbi->s_es;
5442
5443         if (sbi->s_journal) {
5444                 ext4_init_journal_params(sb, sbi->s_journal);
5445                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5446         }
5447
5448         if (*flags & SB_LAZYTIME)
5449                 sb->s_flags |= SB_LAZYTIME;
5450
5451         if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5452                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5453                         err = -EROFS;
5454                         goto restore_opts;
5455                 }
5456
5457                 if (*flags & SB_RDONLY) {
5458                         err = sync_filesystem(sb);
5459                         if (err < 0)
5460                                 goto restore_opts;
5461                         err = dquot_suspend(sb, -1);
5462                         if (err < 0)
5463                                 goto restore_opts;
5464
5465                         /*
5466                          * First of all, the unconditional stuff we have to do
5467                          * to disable replay of the journal when we next remount
5468                          */
5469                         sb->s_flags |= SB_RDONLY;
5470
5471                         /*
5472                          * OK, test if we are remounting a valid rw partition
5473                          * readonly, and if so set the rdonly flag and then
5474                          * mark the partition as valid again.
5475                          */
5476                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5477                             (sbi->s_mount_state & EXT4_VALID_FS))
5478                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5479
5480                         if (sbi->s_journal)
5481                                 ext4_mark_recovery_complete(sb, es);
5482                         if (sbi->s_mmp_tsk)
5483                                 kthread_stop(sbi->s_mmp_tsk);
5484                 } else {
5485                         /* Make sure we can mount this feature set readwrite */
5486                         if (ext4_has_feature_readonly(sb) ||
5487                             !ext4_feature_set_ok(sb, 0)) {
5488                                 err = -EROFS;
5489                                 goto restore_opts;
5490                         }
5491                         /*
5492                          * Make sure the group descriptor checksums
5493                          * are sane.  If they aren't, refuse to remount r/w.
5494                          */
5495                         for (g = 0; g < sbi->s_groups_count; g++) {
5496                                 struct ext4_group_desc *gdp =
5497                                         ext4_get_group_desc(sb, g, NULL);
5498
5499                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5500                                         ext4_msg(sb, KERN_ERR,
5501                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5502                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5503                                                le16_to_cpu(gdp->bg_checksum));
5504                                         err = -EFSBADCRC;
5505                                         goto restore_opts;
5506                                 }
5507                         }
5508
5509                         /*
5510                          * If we have an unprocessed orphan list hanging
5511                          * around from a previously readonly bdev mount,
5512                          * require a full umount/remount for now.
5513                          */
5514                         if (es->s_last_orphan) {
5515                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5516                                        "remount RDWR because of unprocessed "
5517                                        "orphan inode list.  Please "
5518                                        "umount/remount instead");
5519                                 err = -EINVAL;
5520                                 goto restore_opts;
5521                         }
5522
5523                         /*
5524                          * Mounting a RDONLY partition read-write, so reread
5525                          * and store the current valid flag.  (It may have
5526                          * been changed by e2fsck since we originally mounted
5527                          * the partition.)
5528                          */
5529                         if (sbi->s_journal)
5530                                 ext4_clear_journal_err(sb, es);
5531                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5532
5533                         err = ext4_setup_super(sb, es, 0);
5534                         if (err)
5535                                 goto restore_opts;
5536
5537                         sb->s_flags &= ~SB_RDONLY;
5538                         if (ext4_has_feature_mmp(sb))
5539                                 if (ext4_multi_mount_protect(sb,
5540                                                 le64_to_cpu(es->s_mmp_block))) {
5541                                         err = -EROFS;
5542                                         goto restore_opts;
5543                                 }
5544                         enable_quota = 1;
5545                 }
5546         }
5547
5548         /*
5549          * Reinitialize lazy itable initialization thread based on
5550          * current settings
5551          */
5552         if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5553                 ext4_unregister_li_request(sb);
5554         else {
5555                 ext4_group_t first_not_zeroed;
5556                 first_not_zeroed = ext4_has_uninit_itable(sb);
5557                 ext4_register_li_request(sb, first_not_zeroed);
5558         }
5559
5560         ext4_setup_system_zone(sb);
5561         if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5562                 err = ext4_commit_super(sb, 1);
5563                 if (err)
5564                         goto restore_opts;
5565         }
5566
5567 #ifdef CONFIG_QUOTA
5568         /* Release old quota file names */
5569         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5570                 kfree(old_opts.s_qf_names[i]);
5571         if (enable_quota) {
5572                 if (sb_any_quota_suspended(sb))
5573                         dquot_resume(sb, -1);
5574                 else if (ext4_has_feature_quota(sb)) {
5575                         err = ext4_enable_quotas(sb);
5576                         if (err)
5577                                 goto restore_opts;
5578                 }
5579         }
5580 #endif
5581
5582         *flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5583         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5584         kfree(orig_data);
5585         return 0;
5586
5587 restore_opts:
5588         sb->s_flags = old_sb_flags;
5589         sbi->s_mount_opt = old_opts.s_mount_opt;
5590         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5591         sbi->s_resuid = old_opts.s_resuid;
5592         sbi->s_resgid = old_opts.s_resgid;
5593         sbi->s_commit_interval = old_opts.s_commit_interval;
5594         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5595         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5596 #ifdef CONFIG_QUOTA
5597         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5598         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5599                 to_free[i] = get_qf_name(sb, sbi, i);
5600                 rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5601         }
5602         synchronize_rcu();
5603         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5604                 kfree(to_free[i]);
5605 #endif
5606         kfree(orig_data);
5607         return err;
5608 }
5609
5610 #ifdef CONFIG_QUOTA
5611 static int ext4_statfs_project(struct super_block *sb,
5612                                kprojid_t projid, struct kstatfs *buf)
5613 {
5614         struct kqid qid;
5615         struct dquot *dquot;
5616         u64 limit;
5617         u64 curblock;
5618
5619         qid = make_kqid_projid(projid);
5620         dquot = dqget(sb, qid);
5621         if (IS_ERR(dquot))
5622                 return PTR_ERR(dquot);
5623         spin_lock(&dquot->dq_dqb_lock);
5624
5625         limit = dquot->dq_dqb.dqb_bsoftlimit;
5626         if (dquot->dq_dqb.dqb_bhardlimit &&
5627             (!limit || dquot->dq_dqb.dqb_bhardlimit < limit))
5628                 limit = dquot->dq_dqb.dqb_bhardlimit;
5629         limit >>= sb->s_blocksize_bits;
5630
5631         if (limit && buf->f_blocks > limit) {
5632                 curblock = (dquot->dq_dqb.dqb_curspace +
5633                             dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5634                 buf->f_blocks = limit;
5635                 buf->f_bfree = buf->f_bavail =
5636                         (buf->f_blocks > curblock) ?
5637                          (buf->f_blocks - curblock) : 0;
5638         }
5639
5640         limit = dquot->dq_dqb.dqb_isoftlimit;
5641         if (dquot->dq_dqb.dqb_ihardlimit &&
5642             (!limit || dquot->dq_dqb.dqb_ihardlimit < limit))
5643                 limit = dquot->dq_dqb.dqb_ihardlimit;
5644
5645         if (limit && buf->f_files > limit) {
5646                 buf->f_files = limit;
5647                 buf->f_ffree =
5648                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5649                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5650         }
5651
5652         spin_unlock(&dquot->dq_dqb_lock);
5653         dqput(dquot);
5654         return 0;
5655 }
5656 #endif
5657
5658 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5659 {
5660         struct super_block *sb = dentry->d_sb;
5661         struct ext4_sb_info *sbi = EXT4_SB(sb);
5662         struct ext4_super_block *es = sbi->s_es;
5663         ext4_fsblk_t overhead = 0, resv_blocks;
5664         u64 fsid;
5665         s64 bfree;
5666         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5667
5668         if (!test_opt(sb, MINIX_DF))
5669                 overhead = sbi->s_overhead;
5670
5671         buf->f_type = EXT4_SUPER_MAGIC;
5672         buf->f_bsize = sb->s_blocksize;
5673         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5674         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5675                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5676         /* prevent underflow in case that few free space is available */
5677         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5678         buf->f_bavail = buf->f_bfree -
5679                         (ext4_r_blocks_count(es) + resv_blocks);
5680         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5681                 buf->f_bavail = 0;
5682         buf->f_files = le32_to_cpu(es->s_inodes_count);
5683         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5684         buf->f_namelen = EXT4_NAME_LEN;
5685         fsid = le64_to_cpup((void *)es->s_uuid) ^
5686                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5687         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5688         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5689
5690 #ifdef CONFIG_QUOTA
5691         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5692             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5693                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5694 #endif
5695         return 0;
5696 }
5697
5698
5699 #ifdef CONFIG_QUOTA
5700
5701 /*
5702  * Helper functions so that transaction is started before we acquire dqio_sem
5703  * to keep correct lock ordering of transaction > dqio_sem
5704  */
5705 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5706 {
5707         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5708 }
5709
5710 static int ext4_write_dquot(struct dquot *dquot)
5711 {
5712         int ret, err;
5713         handle_t *handle;
5714         struct inode *inode;
5715
5716         inode = dquot_to_inode(dquot);
5717         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5718                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5719         if (IS_ERR(handle))
5720                 return PTR_ERR(handle);
5721         ret = dquot_commit(dquot);
5722         err = ext4_journal_stop(handle);
5723         if (!ret)
5724                 ret = err;
5725         return ret;
5726 }
5727
5728 static int ext4_acquire_dquot(struct dquot *dquot)
5729 {
5730         int ret, err;
5731         handle_t *handle;
5732
5733         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5734                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5735         if (IS_ERR(handle))
5736                 return PTR_ERR(handle);
5737         ret = dquot_acquire(dquot);
5738         err = ext4_journal_stop(handle);
5739         if (!ret)
5740                 ret = err;
5741         return ret;
5742 }
5743
5744 static int ext4_release_dquot(struct dquot *dquot)
5745 {
5746         int ret, err;
5747         handle_t *handle;
5748
5749         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5750                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5751         if (IS_ERR(handle)) {
5752                 /* Release dquot anyway to avoid endless cycle in dqput() */
5753                 dquot_release(dquot);
5754                 return PTR_ERR(handle);
5755         }
5756         ret = dquot_release(dquot);
5757         err = ext4_journal_stop(handle);
5758         if (!ret)
5759                 ret = err;
5760         return ret;
5761 }
5762
5763 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5764 {
5765         struct super_block *sb = dquot->dq_sb;
5766         struct ext4_sb_info *sbi = EXT4_SB(sb);
5767
5768         /* Are we journaling quotas? */
5769         if (ext4_has_feature_quota(sb) ||
5770             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5771                 dquot_mark_dquot_dirty(dquot);
5772                 return ext4_write_dquot(dquot);
5773         } else {
5774                 return dquot_mark_dquot_dirty(dquot);
5775         }
5776 }
5777
5778 static int ext4_write_info(struct super_block *sb, int type)
5779 {
5780         int ret, err;
5781         handle_t *handle;
5782
5783         /* Data block + inode block */
5784         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5785         if (IS_ERR(handle))
5786                 return PTR_ERR(handle);
5787         ret = dquot_commit_info(sb, type);
5788         err = ext4_journal_stop(handle);
5789         if (!ret)
5790                 ret = err;
5791         return ret;
5792 }
5793
5794 /*
5795  * Turn on quotas during mount time - we need to find
5796  * the quota file and such...
5797  */
5798 static int ext4_quota_on_mount(struct super_block *sb, int type)
5799 {
5800         return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5801                                         EXT4_SB(sb)->s_jquota_fmt, type);
5802 }
5803
5804 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5805 {
5806         struct ext4_inode_info *ei = EXT4_I(inode);
5807
5808         /* The first argument of lockdep_set_subclass has to be
5809          * *exactly* the same as the argument to init_rwsem() --- in
5810          * this case, in init_once() --- or lockdep gets unhappy
5811          * because the name of the lock is set using the
5812          * stringification of the argument to init_rwsem().
5813          */
5814         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5815         lockdep_set_subclass(&ei->i_data_sem, subclass);
5816 }
5817
5818 /*
5819  * Standard function to be called on quota_on
5820  */
5821 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5822                          const struct path *path)
5823 {
5824         int err;
5825
5826         if (!test_opt(sb, QUOTA))
5827                 return -EINVAL;
5828
5829         /* Quotafile not on the same filesystem? */
5830         if (path->dentry->d_sb != sb)
5831                 return -EXDEV;
5832         /* Journaling quota? */
5833         if (EXT4_SB(sb)->s_qf_names[type]) {
5834                 /* Quotafile not in fs root? */
5835                 if (path->dentry->d_parent != sb->s_root)
5836                         ext4_msg(sb, KERN_WARNING,
5837                                 "Quota file not on filesystem root. "
5838                                 "Journaled quota will not work");
5839                 sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5840         } else {
5841                 /*
5842                  * Clear the flag just in case mount options changed since
5843                  * last time.
5844                  */
5845                 sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5846         }
5847
5848         /*
5849          * When we journal data on quota file, we have to flush journal to see
5850          * all updates to the file when we bypass pagecache...
5851          */
5852         if (EXT4_SB(sb)->s_journal &&
5853             ext4_should_journal_data(d_inode(path->dentry))) {
5854                 /*
5855                  * We don't need to lock updates but journal_flush() could
5856                  * otherwise be livelocked...
5857                  */
5858                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5859                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5860                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5861                 if (err)
5862                         return err;
5863         }
5864
5865         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5866         err = dquot_quota_on(sb, type, format_id, path);
5867         if (err) {
5868                 lockdep_set_quota_inode(path->dentry->d_inode,
5869                                              I_DATA_SEM_NORMAL);
5870         } else {
5871                 struct inode *inode = d_inode(path->dentry);
5872                 handle_t *handle;
5873
5874                 /*
5875                  * Set inode flags to prevent userspace from messing with quota
5876                  * files. If this fails, we return success anyway since quotas
5877                  * are already enabled and this is not a hard failure.
5878                  */
5879                 inode_lock(inode);
5880                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5881                 if (IS_ERR(handle))
5882                         goto unlock_inode;
5883                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5884                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5885                                 S_NOATIME | S_IMMUTABLE);
5886                 ext4_mark_inode_dirty(handle, inode);
5887                 ext4_journal_stop(handle);
5888         unlock_inode:
5889                 inode_unlock(inode);
5890         }
5891         return err;
5892 }
5893
5894 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5895                              unsigned int flags)
5896 {
5897         int err;
5898         struct inode *qf_inode;
5899         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5900                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5901                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5902                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5903         };
5904
5905         BUG_ON(!ext4_has_feature_quota(sb));
5906
5907         if (!qf_inums[type])
5908                 return -EPERM;
5909
5910         qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5911         if (IS_ERR(qf_inode)) {
5912                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5913                 return PTR_ERR(qf_inode);
5914         }
5915
5916         /* Don't account quota for quota files to avoid recursion */
5917         qf_inode->i_flags |= S_NOQUOTA;
5918         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5919         err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
5920         if (err)
5921                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5922         iput(qf_inode);
5923
5924         return err;
5925 }
5926
5927 /* Enable usage tracking for all quota types. */
5928 static int ext4_enable_quotas(struct super_block *sb)
5929 {
5930         int type, err = 0;
5931         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5932                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5933                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5934                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5935         };
5936         bool quota_mopt[EXT4_MAXQUOTAS] = {
5937                 test_opt(sb, USRQUOTA),
5938                 test_opt(sb, GRPQUOTA),
5939                 test_opt(sb, PRJQUOTA),
5940         };
5941
5942         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5943         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5944                 if (qf_inums[type]) {
5945                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5946                                 DQUOT_USAGE_ENABLED |
5947                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5948                         if (err) {
5949                                 ext4_warning(sb,
5950                                         "Failed to enable quota tracking "
5951                                         "(type=%d, err=%d). Please run "
5952                                         "e2fsck to fix.", type, err);
5953                                 for (type--; type >= 0; type--)
5954                                         dquot_quota_off(sb, type);
5955
5956                                 return err;
5957                         }
5958                 }
5959         }
5960         return 0;
5961 }
5962
5963 static int ext4_quota_off(struct super_block *sb, int type)
5964 {
5965         struct inode *inode = sb_dqopt(sb)->files[type];
5966         handle_t *handle;
5967         int err;
5968
5969         /* Force all delayed allocation blocks to be allocated.
5970          * Caller already holds s_umount sem */
5971         if (test_opt(sb, DELALLOC))
5972                 sync_filesystem(sb);
5973
5974         if (!inode || !igrab(inode))
5975                 goto out;
5976
5977         err = dquot_quota_off(sb, type);
5978         if (err || ext4_has_feature_quota(sb))
5979                 goto out_put;
5980
5981         inode_lock(inode);
5982         /*
5983          * Update modification times of quota files when userspace can
5984          * start looking at them. If we fail, we return success anyway since
5985          * this is not a hard failure and quotas are already disabled.
5986          */
5987         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5988         if (IS_ERR(handle))
5989                 goto out_unlock;
5990         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5991         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5992         inode->i_mtime = inode->i_ctime = current_time(inode);
5993         ext4_mark_inode_dirty(handle, inode);
5994         ext4_journal_stop(handle);
5995 out_unlock:
5996         inode_unlock(inode);
5997 out_put:
5998         lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5999         iput(inode);
6000         return err;
6001 out:
6002         return dquot_quota_off(sb, type);
6003 }
6004
6005 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6006  * acquiring the locks... As quota files are never truncated and quota code
6007  * itself serializes the operations (and no one else should touch the files)
6008  * we don't have to be afraid of races */
6009 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6010                                size_t len, loff_t off)
6011 {
6012         struct inode *inode = sb_dqopt(sb)->files[type];
6013         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6014         int offset = off & (sb->s_blocksize - 1);
6015         int tocopy;
6016         size_t toread;
6017         struct buffer_head *bh;
6018         loff_t i_size = i_size_read(inode);
6019
6020         if (off > i_size)
6021                 return 0;
6022         if (off+len > i_size)
6023                 len = i_size-off;
6024         toread = len;
6025         while (toread > 0) {
6026                 tocopy = sb->s_blocksize - offset < toread ?
6027                                 sb->s_blocksize - offset : toread;
6028                 bh = ext4_bread(NULL, inode, blk, 0);
6029                 if (IS_ERR(bh))
6030                         return PTR_ERR(bh);
6031                 if (!bh)        /* A hole? */
6032                         memset(data, 0, tocopy);
6033                 else
6034                         memcpy(data, bh->b_data+offset, tocopy);
6035                 brelse(bh);
6036                 offset = 0;
6037                 toread -= tocopy;
6038                 data += tocopy;
6039                 blk++;
6040         }
6041         return len;
6042 }
6043
6044 /* Write to quotafile (we know the transaction is already started and has
6045  * enough credits) */
6046 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6047                                 const char *data, size_t len, loff_t off)
6048 {
6049         struct inode *inode = sb_dqopt(sb)->files[type];
6050         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6051         int err, offset = off & (sb->s_blocksize - 1);
6052         int retries = 0;
6053         struct buffer_head *bh;
6054         handle_t *handle = journal_current_handle();
6055
6056         if (EXT4_SB(sb)->s_journal && !handle) {
6057                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6058                         " cancelled because transaction is not started",
6059                         (unsigned long long)off, (unsigned long long)len);
6060                 return -EIO;
6061         }
6062         /*
6063          * Since we account only one data block in transaction credits,
6064          * then it is impossible to cross a block boundary.
6065          */
6066         if (sb->s_blocksize - offset < len) {
6067                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6068                         " cancelled because not block aligned",
6069                         (unsigned long long)off, (unsigned long long)len);
6070                 return -EIO;
6071         }
6072
6073         do {
6074                 bh = ext4_bread(handle, inode, blk,
6075                                 EXT4_GET_BLOCKS_CREATE |
6076                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
6077         } while (PTR_ERR(bh) == -ENOSPC &&
6078                  ext4_should_retry_alloc(inode->i_sb, &retries));
6079         if (IS_ERR(bh))
6080                 return PTR_ERR(bh);
6081         if (!bh)
6082                 goto out;
6083         BUFFER_TRACE(bh, "get write access");
6084         err = ext4_journal_get_write_access(handle, bh);
6085         if (err) {
6086                 brelse(bh);
6087                 return err;
6088         }
6089         lock_buffer(bh);
6090         memcpy(bh->b_data+offset, data, len);
6091         flush_dcache_page(bh->b_page);
6092         unlock_buffer(bh);
6093         err = ext4_handle_dirty_metadata(handle, NULL, bh);
6094         brelse(bh);
6095 out:
6096         if (inode->i_size < off + len) {
6097                 i_size_write(inode, off + len);
6098                 EXT4_I(inode)->i_disksize = inode->i_size;
6099                 ext4_mark_inode_dirty(handle, inode);
6100         }
6101         return len;
6102 }
6103 #endif
6104
6105 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6106                        const char *dev_name, void *data)
6107 {
6108         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6109 }
6110
6111 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6112 static inline void register_as_ext2(void)
6113 {
6114         int err = register_filesystem(&ext2_fs_type);
6115         if (err)
6116                 printk(KERN_WARNING
6117                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6118 }
6119
6120 static inline void unregister_as_ext2(void)
6121 {
6122         unregister_filesystem(&ext2_fs_type);
6123 }
6124
6125 static inline int ext2_feature_set_ok(struct super_block *sb)
6126 {
6127         if (ext4_has_unknown_ext2_incompat_features(sb))
6128                 return 0;
6129         if (sb_rdonly(sb))
6130                 return 1;
6131         if (ext4_has_unknown_ext2_ro_compat_features(sb))
6132                 return 0;
6133         return 1;
6134 }
6135 #else
6136 static inline void register_as_ext2(void) { }
6137 static inline void unregister_as_ext2(void) { }
6138 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6139 #endif
6140
6141 static inline void register_as_ext3(void)
6142 {
6143         int err = register_filesystem(&ext3_fs_type);
6144         if (err)
6145                 printk(KERN_WARNING
6146                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6147 }
6148
6149 static inline void unregister_as_ext3(void)
6150 {
6151         unregister_filesystem(&ext3_fs_type);
6152 }
6153
6154 static inline int ext3_feature_set_ok(struct super_block *sb)
6155 {
6156         if (ext4_has_unknown_ext3_incompat_features(sb))
6157                 return 0;
6158         if (!ext4_has_feature_journal(sb))
6159                 return 0;
6160         if (sb_rdonly(sb))
6161                 return 1;
6162         if (ext4_has_unknown_ext3_ro_compat_features(sb))
6163                 return 0;
6164         return 1;
6165 }
6166
6167 static struct file_system_type ext4_fs_type = {
6168         .owner          = THIS_MODULE,
6169         .name           = "ext4",
6170         .mount          = ext4_mount,
6171         .kill_sb        = kill_block_super,
6172         .fs_flags       = FS_REQUIRES_DEV,
6173 };
6174 MODULE_ALIAS_FS("ext4");
6175
6176 /* Shared across all ext4 file systems */
6177 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6178
6179 static int __init ext4_init_fs(void)
6180 {
6181         int i, err;
6182
6183         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6184         ext4_li_info = NULL;
6185         mutex_init(&ext4_li_mtx);
6186
6187         /* Build-time check for flags consistency */
6188         ext4_check_flag_values();
6189
6190         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6191                 init_waitqueue_head(&ext4__ioend_wq[i]);
6192
6193         err = ext4_init_es();
6194         if (err)
6195                 return err;
6196
6197         err = ext4_init_pending();
6198         if (err)
6199                 goto out7;
6200
6201         err = ext4_init_post_read_processing();
6202         if (err)
6203                 goto out6;
6204
6205         err = ext4_init_pageio();
6206         if (err)
6207                 goto out5;
6208
6209         err = ext4_init_system_zone();
6210         if (err)
6211                 goto out4;
6212
6213         err = ext4_init_sysfs();
6214         if (err)
6215                 goto out3;
6216
6217         err = ext4_init_mballoc();
6218         if (err)
6219                 goto out2;
6220         err = init_inodecache();
6221         if (err)
6222                 goto out1;
6223         register_as_ext3();
6224         register_as_ext2();
6225         err = register_filesystem(&ext4_fs_type);
6226         if (err)
6227                 goto out;
6228
6229         return 0;
6230 out:
6231         unregister_as_ext2();
6232         unregister_as_ext3();
6233         destroy_inodecache();
6234 out1:
6235         ext4_exit_mballoc();
6236 out2:
6237         ext4_exit_sysfs();
6238 out3:
6239         ext4_exit_system_zone();
6240 out4:
6241         ext4_exit_pageio();
6242 out5:
6243         ext4_exit_post_read_processing();
6244 out6:
6245         ext4_exit_pending();
6246 out7:
6247         ext4_exit_es();
6248
6249         return err;
6250 }
6251
6252 static void __exit ext4_exit_fs(void)
6253 {
6254         ext4_destroy_lazyinit_thread();
6255         unregister_as_ext2();
6256         unregister_as_ext3();
6257         unregister_filesystem(&ext4_fs_type);
6258         destroy_inodecache();
6259         ext4_exit_mballoc();
6260         ext4_exit_sysfs();
6261         ext4_exit_system_zone();
6262         ext4_exit_pageio();
6263         ext4_exit_post_read_processing();
6264         ext4_exit_es();
6265         ext4_exit_pending();
6266 }
6267
6268 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6269 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6270 MODULE_LICENSE("GPL");
6271 MODULE_SOFTDEP("pre: crc32c");
6272 module_init(ext4_init_fs)
6273 module_exit(ext4_exit_fs)