fs/gfs2/ops_fstype.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/sched.h>
  13 #include <linux/slab.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/completion.h>
  16 #include <linux/buffer_head.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/kthread.h>
  19 #include <linux/export.h>
  20 #include <linux/namei.h>
  21 #include <linux/mount.h>
  22 #include <linux/gfs2_ondisk.h>
  23 #include <linux/quotaops.h>
  24 #include <linux/lockdep.h>
  25 #include <linux/module.h>
  26 #include <linux/backing-dev.h>
  27
  28 #include "gfs2.h"
  29 #include "incore.h"
  30 #include "bmap.h"
  31 #include "glock.h"
  32 #include "glops.h"
  33 #include "inode.h"
  34 #include "recovery.h"
  35 #include "rgrp.h"
  36 #include "super.h"
  37 #include "sys.h"
  38 #include "util.h"
  39 #include "log.h"
  40 #include "quota.h"
  41 #include "dir.h"
  42 #include "meta_io.h"
  43 #include "trace_gfs2.h"
  44
  45 #define DO 0
  46 #define UNDO 1
  47
  48 /**
  49  * gfs2_tune_init - Fill a gfs2_tune structure with default values
  50  * @gt: tune
  51  *
  52  */
  53
  54 static void gfs2_tune_init(struct gfs2_tune *gt)
  55 {
  56         spin_lock_init(&gt->gt_spin);
  57
  58         gt->gt_quota_warn_period = 10;
  59         gt->gt_quota_scale_num = 1;
  60         gt->gt_quota_scale_den = 1;
  61         gt->gt_new_files_jdata = 0;
  62         gt->gt_max_readahead = BIT(18);
  63         gt->gt_complain_secs = 10;
  64 }
  65
  66 static struct gfs2_sbd *init_sbd(struct super_block *sb)
  67 {
  68         struct gfs2_sbd *sdp;
  69         struct address_space *mapping;
  70
  71         sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
  72         if (!sdp)
  73                 return NULL;
  74
  75         sdp->sd_vfs = sb;
  76         sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
  77         if (!sdp->sd_lkstats) {
  78                 kfree(sdp);
  79                 return NULL;
  80         }
  81         sb->s_fs_info = sdp;
  82
  83         set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
  84         gfs2_tune_init(&sdp->sd_tune);
  85
  86         init_waitqueue_head(&sdp->sd_glock_wait);
  87         atomic_set(&sdp->sd_glock_disposal, 0);
  88         init_completion(&sdp->sd_locking_init);
  89         init_completion(&sdp->sd_wdack);
  90         spin_lock_init(&sdp->sd_statfs_spin);
  91
  92         spin_lock_init(&sdp->sd_rindex_spin);
  93         sdp->sd_rindex_tree.rb_node = NULL;
  94
  95         INIT_LIST_HEAD(&sdp->sd_jindex_list);
  96         spin_lock_init(&sdp->sd_jindex_spin);
  97         mutex_init(&sdp->sd_jindex_mutex);
  98         init_completion(&sdp->sd_journal_ready);
  99
 100         INIT_LIST_HEAD(&sdp->sd_quota_list);
 101         mutex_init(&sdp->sd_quota_mutex);
 102         mutex_init(&sdp->sd_quota_sync_mutex);
 103         init_waitqueue_head(&sdp->sd_quota_wait);
 104         INIT_LIST_HEAD(&sdp->sd_trunc_list);
 105         spin_lock_init(&sdp->sd_trunc_lock);
 106         spin_lock_init(&sdp->sd_bitmap_lock);
 107
 108         mapping = &sdp->sd_aspace;
 109
 110         address_space_init_once(mapping);
 111         mapping->a_ops = &gfs2_rgrp_aops;
 112         mapping->host = sb->s_bdev->bd_inode;
 113         mapping->flags = 0;
 114         mapping_set_gfp_mask(mapping, GFP_NOFS);
 115         mapping->private_data = NULL;
 116         mapping->writeback_index = 0;
 117
 118         spin_lock_init(&sdp->sd_log_lock);
 119         atomic_set(&sdp->sd_log_pinned, 0);
 120         INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
 121         INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
 122         spin_lock_init(&sdp->sd_ordered_lock);
 123
 124         init_waitqueue_head(&sdp->sd_log_waitq);
 125         init_waitqueue_head(&sdp->sd_logd_waitq);
 126         spin_lock_init(&sdp->sd_ail_lock);
 127         INIT_LIST_HEAD(&sdp->sd_ail1_list);
 128         INIT_LIST_HEAD(&sdp->sd_ail2_list);
 129
 130         init_rwsem(&sdp->sd_log_flush_lock);
 131         atomic_set(&sdp->sd_log_in_flight, 0);
 132         atomic_set(&sdp->sd_reserving_log, 0);
 133         init_waitqueue_head(&sdp->sd_reserving_log_wait);
 134         init_waitqueue_head(&sdp->sd_log_flush_wait);
 135         atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
 136         mutex_init(&sdp->sd_freeze_mutex);
 137
 138         return sdp;
 139 }
 140
 141
 142 /**
 143  * gfs2_check_sb - Check superblock
 144  * @sdp: the filesystem
 145  * @sb: The superblock
 146  * @silent: Don't print a message if the check fails
 147  *
 148  * Checks the version code of the FS is one that we understand how to
 149  * read and that the sizes of the various on-disk structures have not
 150  * changed.
 151  */
 152
 153 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 154 {
 155         struct gfs2_sb_host *sb = &sdp->sd_sb;
 156
 157         if (sb->sb_magic != GFS2_MAGIC ||
 158             sb->sb_type != GFS2_METATYPE_SB) {
 159                 if (!silent)
 160                         pr_warn("not a GFS2 filesystem\n");
 161                 return -EINVAL;
 162         }
 163
 164         /*  If format numbers match exactly, we're done.  */
 165
 166         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
 167             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
 168                 return 0;
 169
 170         fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
 171
 172         return -EINVAL;
 173 }
 174
 175 static void end_bio_io_page(struct bio *bio)
 176 {
 177         struct page *page = bio->bi_private;
 178
 179         if (!bio->bi_status)
 180                 SetPageUptodate(page);
 181         else
 182                 pr_warn("error %d reading superblock\n", bio->bi_status);
 183         unlock_page(page);
 184 }
 185
 186 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
 187 {
 188         struct gfs2_sb_host *sb = &sdp->sd_sb;
 189         struct super_block *s = sdp->sd_vfs;
 190         const struct gfs2_sb *str = buf;
 191
 192         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
 193         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
 194         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
 195         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
 196         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
 197         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
 198         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
 199         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
 200         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
 201         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
 202         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
 203
 204         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
 205         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
 206         memcpy(&s->s_uuid, str->sb_uuid, 16);
 207 }
 208
 209 /**
 210  * gfs2_read_super - Read the gfs2 super block from disk
 211  * @sdp: The GFS2 super block
 212  * @sector: The location of the super block
 213  * @error: The error code to return
 214  *
 215  * This uses the bio functions to read the super block from disk
 216  * because we want to be 100% sure that we never read cached data.
 217  * A super block is read twice only during each GFS2 mount and is
 218  * never written to by the filesystem. The first time its read no
 219  * locks are held, and the only details which are looked at are those
 220  * relating to the locking protocol. Once locking is up and working,
 221  * the sb is read again under the lock to establish the location of
 222  * the master directory (contains pointers to journals etc) and the
 223  * root directory.
 224  *
 225  * Returns: 0 on success or error
 226  */
 227
 228 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
 229 {
 230         struct super_block *sb = sdp->sd_vfs;
 231         struct gfs2_sb *p;
 232         struct page *page;
 233         struct bio *bio;
 234
 235         page = alloc_page(GFP_NOFS);
 236         if (unlikely(!page))
 237                 return -ENOMEM;
 238
 239         ClearPageUptodate(page);
 240         ClearPageDirty(page);
 241         lock_page(page);
 242
 243         bio = bio_alloc(GFP_NOFS, 1);
 244         bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
 245         bio_set_dev(bio, sb->s_bdev);
 246         bio_add_page(bio, page, PAGE_SIZE, 0);
 247
 248         bio->bi_end_io = end_bio_io_page;
 249         bio->bi_private = page;
 250         bio_set_op_attrs(bio, REQ_OP_READ, REQ_META);
 251         submit_bio(bio);
 252         wait_on_page_locked(page);
 253         bio_put(bio);
 254         if (!PageUptodate(page)) {
 255                 __free_page(page);
 256                 return -EIO;
 257         }
 258         p = kmap(page);
 259         gfs2_sb_in(sdp, p);
 260         kunmap(page);
 261         __free_page(page);
 262         return gfs2_check_sb(sdp, silent);
 263 }
 264
 265 /**
 266  * gfs2_read_sb - Read super block
 267  * @sdp: The GFS2 superblock
 268  * @silent: Don't print message if mount fails
 269  *
 270  */
 271
 272 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
 273 {
 274         u32 hash_blocks, ind_blocks, leaf_blocks;
 275         u32 tmp_blocks;
 276         unsigned int x;
 277         int error;
 278
 279         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 280         if (error) {
 281                 if (!silent)
 282                         fs_err(sdp, "can't read superblock\n");
 283                 return error;
 284         }
 285
 286         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 287                                GFS2_BASIC_BLOCK_SHIFT;
 288         sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
 289         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 290                           sizeof(struct gfs2_dinode)) / sizeof(u64);
 291         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 292                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
 293         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 294         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 295         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 296         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
 297         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 298                                 sizeof(struct gfs2_meta_header)) /
 299                                 sizeof(struct gfs2_quota_change);
 300         sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
 301                                      sizeof(struct gfs2_meta_header))
 302                 * GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
 303
 304         /* Compute maximum reservation required to add a entry to a directory */
 305
 306         hash_blocks = DIV_ROUND_UP(sizeof(u64) * BIT(GFS2_DIR_MAX_DEPTH),
 307                              sdp->sd_jbsize);
 308
 309         ind_blocks = 0;
 310         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 311                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
 312                 ind_blocks += tmp_blocks;
 313         }
 314
 315         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 316
 317         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 318
 319         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 320                                 sizeof(struct gfs2_dinode);
 321         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 322         for (x = 2;; x++) {
 323                 u64 space, d;
 324                 u32 m;
 325
 326                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 327                 d = space;
 328                 m = do_div(d, sdp->sd_inptrs);
 329
 330                 if (d != sdp->sd_heightsize[x - 1] || m)
 331                         break;
 332                 sdp->sd_heightsize[x] = space;
 333         }
 334         sdp->sd_max_height = x;
 335         sdp->sd_heightsize[x] = ~0;
 336         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 337
 338         sdp->sd_max_dents_per_leaf = (sdp->sd_sb.sb_bsize -
 339                                       sizeof(struct gfs2_leaf)) /
 340                                      GFS2_MIN_DIRENT_SIZE;
 341         return 0;
 342 }
 343
 344 static int init_names(struct gfs2_sbd *sdp, int silent)
 345 {
 346         char *proto, *table;
 347         int error = 0;
 348
 349         proto = sdp->sd_args.ar_lockproto;
 350         table = sdp->sd_args.ar_locktable;
 351
 352         /*  Try to autodetect  */
 353
 354         if (!proto[0] || !table[0]) {
 355                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 356                 if (error)
 357                         return error;
 358
 359                 if (!proto[0])
 360                         proto = sdp->sd_sb.sb_lockproto;
 361                 if (!table[0])
 362                         table = sdp->sd_sb.sb_locktable;
 363         }
 364
 365         if (!table[0])
 366                 table = sdp->sd_vfs->s_id;
 367
 368         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
 369         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
 370
 371         table = sdp->sd_table_name;
 372         while ((table = strchr(table, '/')))
 373                 *table = '_';
 374
 375         return error;
 376 }
 377
 378 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
 379                         int undo)
 380 {
 381         int error = 0;
 382
 383         if (undo)
 384                 goto fail_trans;
 385
 386         error = gfs2_glock_nq_num(sdp,
 387                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
 388                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
 389                                   mount_gh);
 390         if (error) {
 391                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
 392                 goto fail;
 393         }
 394
 395         error = gfs2_glock_nq_num(sdp,
 396                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
 397                                   LM_ST_SHARED,
 398                                   LM_FLAG_NOEXP | GL_EXACT,
 399                                   &sdp->sd_live_gh);
 400         if (error) {
 401                 fs_err(sdp, "can't acquire live glock: %d\n", error);
 402                 goto fail_mount;
 403         }
 404
 405         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
 406                                CREATE, &sdp->sd_rename_gl);
 407         if (error) {
 408                 fs_err(sdp, "can't create rename glock: %d\n", error);
 409                 goto fail_live;
 410         }
 411
 412         error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
 413                                CREATE, &sdp->sd_freeze_gl);
 414         if (error) {
 415                 fs_err(sdp, "can't create transaction glock: %d\n", error);
 416                 goto fail_rename;
 417         }
 418
 419         return 0;
 420
 421 fail_trans:
 422         gfs2_glock_put(sdp->sd_freeze_gl);
 423 fail_rename:
 424         gfs2_glock_put(sdp->sd_rename_gl);
 425 fail_live:
 426         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
 427 fail_mount:
 428         gfs2_glock_dq_uninit(mount_gh);
 429 fail:
 430         return error;
 431 }
 432
 433 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
 434                             u64 no_addr, const char *name)
 435 {
 436         struct gfs2_sbd *sdp = sb->s_fs_info;
 437         struct dentry *dentry;
 438         struct inode *inode;
 439
 440         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0,
 441                                   GFS2_BLKST_FREE /* ignore */);
 442         if (IS_ERR(inode)) {
 443                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
 444                 return PTR_ERR(inode);
 445         }
 446         dentry = d_make_root(inode);
 447         if (!dentry) {
 448                 fs_err(sdp, "can't alloc %s dentry\n", name);
 449                 return -ENOMEM;
 450         }
 451         *dptr = dentry;
 452         return 0;
 453 }
 454
 455 static int init_sb(struct gfs2_sbd *sdp, int silent)
 456 {
 457         struct super_block *sb = sdp->sd_vfs;
 458         struct gfs2_holder sb_gh;
 459         u64 no_addr;
 460         int ret;
 461
 462         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
 463                                 LM_ST_SHARED, 0, &sb_gh);
 464         if (ret) {
 465                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
 466                 return ret;
 467         }
 468
 469         ret = gfs2_read_sb(sdp, silent);
 470         if (ret) {
 471                 fs_err(sdp, "can't read superblock: %d\n", ret);
 472                 goto out;
 473         }
 474
 475         /* Set up the buffer cache and SB for real */
 476         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
 477                 ret = -EINVAL;
 478                 fs_err(sdp, "FS block size (%u) is too small for device "
 479                        "block size (%u)\n",
 480                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
 481                 goto out;
 482         }
 483         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
 484                 ret = -EINVAL;
 485                 fs_err(sdp, "FS block size (%u) is too big for machine "
 486                        "page size (%u)\n",
 487                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
 488                 goto out;
 489         }
 490         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
 491
 492         /* Get the root inode */
 493         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
 494         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
 495         if (ret)
 496                 goto out;
 497
 498         /* Get the master inode */
 499         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
 500         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
 501         if (ret) {
 502                 dput(sdp->sd_root_dir);
 503                 goto out;
 504         }
 505         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
 506 out:
 507         gfs2_glock_dq_uninit(&sb_gh);
 508         return ret;
 509 }
 510
 511 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
 512 {
 513         char *message = "FIRSTMOUNT=Done";
 514         char *envp[] = { message, NULL };
 515
 516         fs_info(sdp, "first mount done, others may mount\n");
 517
 518         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
 519                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
 520
 521         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 522 }
 523
 524 /**
 525  * gfs2_jindex_hold - Grab a lock on the jindex
 526  * @sdp: The GFS2 superblock
 527  * @ji_gh: the holder for the jindex glock
 528  *
 529  * Returns: errno
 530  */
 531
 532 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 533 {
 534         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
 535         struct qstr name;
 536         char buf[20];
 537         struct gfs2_jdesc *jd;
 538         int error;
 539
 540         name.name = buf;
 541
 542         mutex_lock(&sdp->sd_jindex_mutex);
 543
 544         for (;;) {
 545                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
 546                 if (error)
 547                         break;
 548
 549                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 550                 name.hash = gfs2_disk_hash(name.name, name.len);
 551
 552                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
 553                 if (error == -ENOENT) {
 554                         error = 0;
 555                         break;
 556                 }
 557
 558                 gfs2_glock_dq_uninit(ji_gh);
 559
 560                 if (error)
 561                         break;
 562
 563                 error = -ENOMEM;
 564                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 565                 if (!jd)
 566                         break;
 567
 568                 INIT_LIST_HEAD(&jd->extent_list);
 569                 INIT_LIST_HEAD(&jd->jd_revoke_list);
 570
 571                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
 572                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
 573                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
 574                         if (!jd->jd_inode)
 575                                 error = -ENOENT;
 576                         else
 577                                 error = PTR_ERR(jd->jd_inode);
 578                         kfree(jd);
 579                         break;
 580                 }
 581
 582                 spin_lock(&sdp->sd_jindex_spin);
 583                 jd->jd_jid = sdp->sd_journals++;
 584                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 585                 spin_unlock(&sdp->sd_jindex_spin);
 586         }
 587
 588         mutex_unlock(&sdp->sd_jindex_mutex);
 589
 590         return error;
 591 }
 592
 593 /**
 594  * check_journal_clean - Make sure a journal is clean for a spectator mount
 595  * @sdp: The GFS2 superblock
 596  * @jd: The journal descriptor
 597  *
 598  * Returns: 0 if the journal is clean or locked, else an error
 599  */
 600 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 601 {
 602         int error;
 603         struct gfs2_holder j_gh;
 604         struct gfs2_log_header_host head;
 605         struct gfs2_inode *ip;
 606
 607         ip = GFS2_I(jd->jd_inode);
 608         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
 609                                    GL_EXACT | GL_NOCACHE, &j_gh);
 610         if (error) {
 611                 fs_err(sdp, "Error locking journal for spectator mount.\n");
 612                 return -EPERM;
 613         }
 614         error = gfs2_jdesc_check(jd);
 615         if (error) {
 616                 fs_err(sdp, "Error checking journal for spectator mount.\n");
 617                 goto out_unlock;
 618         }
 619         error = gfs2_find_jhead(jd, &head);
 620         if (error) {
 621                 fs_err(sdp, "Error parsing journal for spectator mount.\n");
 622                 goto out_unlock;
 623         }
 624         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 625                 error = -EPERM;
 626                 fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
 627                        "must not be a spectator.\n", jd->jd_jid);
 628         }
 629
 630 out_unlock:
 631         gfs2_glock_dq_uninit(&j_gh);
 632         return error;
 633 }
 634
 635 static int init_journal(struct gfs2_sbd *sdp, int undo)
 636 {
 637         struct inode *master = d_inode(sdp->sd_master_dir);
 638         struct gfs2_holder ji_gh;
 639         struct gfs2_inode *ip;
 640         int jindex = 1;
 641         int error = 0;
 642
 643         if (undo) {
 644                 jindex = 0;
 645                 goto fail_jinode_gh;
 646         }
 647
 648         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
 649         if (IS_ERR(sdp->sd_jindex)) {
 650                 fs_err(sdp, "can't lookup journal index: %d\n", error);
 651                 return PTR_ERR(sdp->sd_jindex);
 652         }
 653
 654         /* Load in the journal index special file */
 655
 656         error = gfs2_jindex_hold(sdp, &ji_gh);
 657         if (error) {
 658                 fs_err(sdp, "can't read journal index: %d\n", error);
 659                 goto fail;
 660         }
 661
 662         error = -EUSERS;
 663         if (!gfs2_jindex_size(sdp)) {
 664                 fs_err(sdp, "no journals!\n");
 665                 goto fail_jindex;
 666         }
 667
 668         atomic_set(&sdp->sd_log_blks_needed, 0);
 669         if (sdp->sd_args.ar_spectator) {
 670                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
 671                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 672                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 673                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 674         } else {
 675                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
 676                         fs_err(sdp, "can't mount journal #%u\n",
 677                                sdp->sd_lockstruct.ls_jid);
 678                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
 679                                gfs2_jindex_size(sdp),
 680                                gfs2_jindex_size(sdp) - 1);
 681                         goto fail_jindex;
 682                 }
 683                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
 684
 685                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
 686                                           &gfs2_journal_glops,
 687                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
 688                                           &sdp->sd_journal_gh);
 689                 if (error) {
 690                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
 691                         goto fail_jindex;
 692                 }
 693
 694                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 695                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 696                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
 697                                            &sdp->sd_jinode_gh);
 698                 if (error) {
 699                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
 700                                error);
 701                         goto fail_journal_gh;
 702                 }
 703
 704                 error = gfs2_jdesc_check(sdp->sd_jdesc);
 705                 if (error) {
 706                         fs_err(sdp, "my journal (%u) is bad: %d\n",
 707                                sdp->sd_jdesc->jd_jid, error);
 708                         goto fail_jinode_gh;
 709                 }
 710                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 711                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 712                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 713
 714                 /* Map the extents for this journal's blocks */
 715                 gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
 716         }
 717         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
 718
 719         if (sdp->sd_lockstruct.ls_first) {
 720                 unsigned int x;
 721                 for (x = 0; x < sdp->sd_journals; x++) {
 722                         struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
 723
 724                         if (sdp->sd_args.ar_spectator) {
 725                                 error = check_journal_clean(sdp, jd);
 726                                 if (error)
 727                                         goto fail_jinode_gh;
 728                                 continue;
 729                         }
 730                         error = gfs2_recover_journal(jd, true);
 731                         if (error) {
 732                                 fs_err(sdp, "error recovering journal %u: %d\n",
 733                                        x, error);
 734                                 goto fail_jinode_gh;
 735                         }
 736                 }
 737
 738                 gfs2_others_may_mount(sdp);
 739         } else if (!sdp->sd_args.ar_spectator) {
 740                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
 741                 if (error) {
 742                         fs_err(sdp, "error recovering my journal: %d\n", error);
 743                         goto fail_jinode_gh;
 744                 }
 745         }
 746
 747         sdp->sd_log_idle = 1;
 748         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
 749         gfs2_glock_dq_uninit(&ji_gh);
 750         jindex = 0;
 751         INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
 752         return 0;
 753
 754 fail_jinode_gh:
 755         if (!sdp->sd_args.ar_spectator)
 756                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
 757 fail_journal_gh:
 758         if (!sdp->sd_args.ar_spectator)
 759                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
 760 fail_jindex:
 761         gfs2_jindex_free(sdp);
 762         if (jindex)
 763                 gfs2_glock_dq_uninit(&ji_gh);
 764 fail:
 765         iput(sdp->sd_jindex);
 766         return error;
 767 }
 768
 769 static struct lock_class_key gfs2_quota_imutex_key;
 770
 771 static int init_inodes(struct gfs2_sbd *sdp, int undo)
 772 {
 773         int error = 0;
 774         struct inode *master = d_inode(sdp->sd_master_dir);
 775
 776         if (undo)
 777                 goto fail_qinode;
 778
 779         error = init_journal(sdp, undo);
 780         complete_all(&sdp->sd_journal_ready);
 781         if (error)
 782                 goto fail;
 783
 784         /* Read in the master statfs inode */
 785         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
 786         if (IS_ERR(sdp->sd_statfs_inode)) {
 787                 error = PTR_ERR(sdp->sd_statfs_inode);
 788                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
 789                 goto fail_journal;
 790         }
 791
 792         /* Read in the resource index inode */
 793         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
 794         if (IS_ERR(sdp->sd_rindex)) {
 795                 error = PTR_ERR(sdp->sd_rindex);
 796                 fs_err(sdp, "can't get resource index inode: %d\n", error);
 797                 goto fail_statfs;
 798         }
 799         sdp->sd_rindex_uptodate = 0;
 800
 801         /* Read in the quota inode */
 802         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
 803         if (IS_ERR(sdp->sd_quota_inode)) {
 804                 error = PTR_ERR(sdp->sd_quota_inode);
 805                 fs_err(sdp, "can't get quota file inode: %d\n", error);
 806                 goto fail_rindex;
 807         }
 808         /*
 809          * i_rwsem on quota files is special. Since this inode is hidden system
 810          * file, we are safe to define locking ourselves.
 811          */
 812         lockdep_set_class(&sdp->sd_quota_inode->i_rwsem,
 813                           &gfs2_quota_imutex_key);
 814
 815         error = gfs2_rindex_update(sdp);
 816         if (error)
 817                 goto fail_qinode;
 818
 819         return 0;
 820
 821 fail_qinode:
 822         iput(sdp->sd_quota_inode);
 823 fail_rindex:
 824         gfs2_clear_rgrpd(sdp);
 825         iput(sdp->sd_rindex);
 826 fail_statfs:
 827         iput(sdp->sd_statfs_inode);
 828 fail_journal:
 829         init_journal(sdp, UNDO);
 830 fail:
 831         return error;
 832 }
 833
 834 static int init_per_node(struct gfs2_sbd *sdp, int undo)
 835 {
 836         struct inode *pn = NULL;
 837         char buf[30];
 838         int error = 0;
 839         struct gfs2_inode *ip;
 840         struct inode *master = d_inode(sdp->sd_master_dir);
 841
 842         if (sdp->sd_args.ar_spectator)
 843                 return 0;
 844
 845         if (undo)
 846                 goto fail_qc_gh;
 847
 848         pn = gfs2_lookup_simple(master, "per_node");
 849         if (IS_ERR(pn)) {
 850                 error = PTR_ERR(pn);
 851                 fs_err(sdp, "can't find per_node directory: %d\n", error);
 852                 return error;
 853         }
 854
 855         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
 856         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
 857         if (IS_ERR(sdp->sd_sc_inode)) {
 858                 error = PTR_ERR(sdp->sd_sc_inode);
 859                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
 860                 goto fail;
 861         }
 862
 863         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
 864         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
 865         if (IS_ERR(sdp->sd_qc_inode)) {
 866                 error = PTR_ERR(sdp->sd_qc_inode);
 867                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
 868                 goto fail_ut_i;
 869         }
 870
 871         iput(pn);
 872         pn = NULL;
 873
 874         ip = GFS2_I(sdp->sd_sc_inode);
 875         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 876                                    &sdp->sd_sc_gh);
 877         if (error) {
 878                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
 879                 goto fail_qc_i;
 880         }
 881
 882         ip = GFS2_I(sdp->sd_qc_inode);
 883         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 884                                    &sdp->sd_qc_gh);
 885         if (error) {
 886                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
 887                 goto fail_ut_gh;
 888         }
 889
 890         return 0;
 891
 892 fail_qc_gh:
 893         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 894 fail_ut_gh:
 895         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 896 fail_qc_i:
 897         iput(sdp->sd_qc_inode);
 898 fail_ut_i:
 899         iput(sdp->sd_sc_inode);
 900 fail:
 901         iput(pn);
 902         return error;
 903 }
 904
 905 static const match_table_t nolock_tokens = {
 906         { Opt_jid, "jid=%d\n", },
 907         { Opt_err, NULL },
 908 };
 909
 910 static const struct lm_lockops nolock_ops = {
 911         .lm_proto_name = "lock_nolock",
 912         .lm_put_lock = gfs2_glock_free,
 913         .lm_tokens = &nolock_tokens,
 914 };
 915
 916 /**
 917  * gfs2_lm_mount - mount a locking protocol
 918  * @sdp: the filesystem
 919  * @args: mount arguments
 920  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
 921  *
 922  * Returns: errno
 923  */
 924
 925 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
 926 {
 927         const struct lm_lockops *lm;
 928         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 929         struct gfs2_args *args = &sdp->sd_args;
 930         const char *proto = sdp->sd_proto_name;
 931         const char *table = sdp->sd_table_name;
 932         char *o, *options;
 933         int ret;
 934
 935         if (!strcmp("lock_nolock", proto)) {
 936                 lm = &nolock_ops;
 937                 sdp->sd_args.ar_localflocks = 1;
 938 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
 939         } else if (!strcmp("lock_dlm", proto)) {
 940                 lm = &gfs2_dlm_ops;
 941 #endif
 942         } else {
 943                 pr_info("can't find protocol %s\n", proto);
 944                 return -ENOENT;
 945         }
 946
 947         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
 948
 949         ls->ls_ops = lm;
 950         ls->ls_first = 1;
 951
 952         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
 953                 substring_t tmp[MAX_OPT_ARGS];
 954                 int token, option;
 955
 956                 if (!o || !*o)
 957                         continue;
 958
 959                 token = match_token(o, *lm->lm_tokens, tmp);
 960                 switch (token) {
 961                 case Opt_jid:
 962                         ret = match_int(&tmp[0], &option);
 963                         if (ret || option < 0)
 964                                 goto hostdata_error;
 965                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
 966                                 ls->ls_jid = option;
 967                         break;
 968                 case Opt_id:
 969                 case Opt_nodir:
 970                         /* Obsolete, but left for backward compat purposes */
 971                         break;
 972                 case Opt_first:
 973                         ret = match_int(&tmp[0], &option);
 974                         if (ret || (option != 0 && option != 1))
 975                                 goto hostdata_error;
 976                         ls->ls_first = option;
 977                         break;
 978                 case Opt_err:
 979                 default:
 980 hostdata_error:
 981                         fs_info(sdp, "unknown hostdata (%s)\n", o);
 982                         return -EINVAL;
 983                 }
 984         }
 985
 986         if (lm->lm_mount == NULL) {
 987                 fs_info(sdp, "Now mounting FS...\n");
 988                 complete_all(&sdp->sd_locking_init);
 989                 return 0;
 990         }
 991         ret = lm->lm_mount(sdp, table);
 992         if (ret == 0)
 993                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
 994         complete_all(&sdp->sd_locking_init);
 995         return ret;
 996 }
 997
 998 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
 999 {
1000         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1001         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1002             lm->lm_unmount)
1003                 lm->lm_unmount(sdp);
1004 }
1005
1006 static int wait_on_journal(struct gfs2_sbd *sdp)
1007 {
1008         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1009                 return 0;
1010
1011         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1012                 ? -EINTR : 0;
1013 }
1014
1015 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1016 {
1017         struct super_block *sb = sdp->sd_vfs;
1018         char ro[20];
1019         char spectator[20];
1020         char *envp[] = { ro, spectator, NULL };
1021         sprintf(ro, "RDONLY=%d", sb_rdonly(sb));
1022         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1023         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1024 }
1025
1026 /**
1027  * fill_super - Read in superblock
1028  * @sb: The VFS superblock
1029  * @data: Mount options
1030  * @silent: Don't complain if it's not a GFS2 filesystem
1031  *
1032  * Returns: errno
1033  */
1034
1035 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1036 {
1037         struct gfs2_sbd *sdp;
1038         struct gfs2_holder mount_gh;
1039         int error;
1040
1041         sdp = init_sbd(sb);
1042         if (!sdp) {
1043                 pr_warn("can't alloc struct gfs2_sbd\n");
1044                 return -ENOMEM;
1045         }
1046         sdp->sd_args = *args;
1047
1048         if (sdp->sd_args.ar_spectator) {
1049                 sb->s_flags |= SB_RDONLY;
1050                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1051         }
1052         if (sdp->sd_args.ar_posix_acl)
1053                 sb->s_flags |= SB_POSIXACL;
1054         if (sdp->sd_args.ar_nobarrier)
1055                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1056
1057         sb->s_flags |= SB_NOSEC;
1058         sb->s_magic = GFS2_MAGIC;
1059         sb->s_op = &gfs2_super_ops;
1060         sb->s_d_op = &gfs2_dops;
1061         sb->s_export_op = &gfs2_export_ops;
1062         sb->s_xattr = gfs2_xattr_handlers;
1063         sb->s_qcop = &gfs2_quotactl_ops;
1064         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1065         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1066         sb->s_time_gran = 1;
1067         sb->s_maxbytes = MAX_LFS_FILESIZE;
1068
1069         /* Set up the buffer cache and fill in some fake block size values
1070            to allow us to read-in the on-disk superblock. */
1071         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1072         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1073         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1074                                GFS2_BASIC_BLOCK_SHIFT;
1075         sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
1076
1077         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1078         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1079         if (sdp->sd_args.ar_statfs_quantum) {
1080                 sdp->sd_tune.gt_statfs_slow = 0;
1081                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1082         } else {
1083                 sdp->sd_tune.gt_statfs_slow = 1;
1084                 sdp->sd_tune.gt_statfs_quantum = 30;
1085         }
1086
1087         error = init_names(sdp, silent);
1088         if (error) {
1089                 /* In this case, we haven't initialized sysfs, so we have to
1090                    manually free the sdp. */
1091                 free_percpu(sdp->sd_lkstats);
1092                 kfree(sdp);
1093                 sb->s_fs_info = NULL;
1094                 return error;
1095         }
1096
1097         snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s", sdp->sd_table_name);
1098
1099         error = gfs2_sys_fs_add(sdp);
1100         /*
1101          * If we hit an error here, gfs2_sys_fs_add will have called function
1102          * kobject_put which causes the sysfs usage count to go to zero, which
1103          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1104          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1105          * kobject_put to free sdp.
1106          */
1107         if (error)
1108                 return error;
1109
1110         gfs2_create_debugfs_file(sdp);
1111
1112         error = gfs2_lm_mount(sdp, silent);
1113         if (error)
1114                 goto fail_debug;
1115
1116         error = init_locking(sdp, &mount_gh, DO);
1117         if (error)
1118                 goto fail_lm;
1119
1120         error = init_sb(sdp, silent);
1121         if (error)
1122                 goto fail_locking;
1123
1124         error = wait_on_journal(sdp);
1125         if (error)
1126                 goto fail_sb;
1127
1128         /*
1129          * If user space has failed to join the cluster or some similar
1130          * failure has occurred, then the journal id will contain a
1131          * negative (error) number. This will then be returned to the
1132          * caller (of the mount syscall). We do this even for spectator
1133          * mounts (which just write a jid of 0 to indicate "ok" even though
1134          * the jid is unused in the spectator case)
1135          */
1136         if (sdp->sd_lockstruct.ls_jid < 0) {
1137                 error = sdp->sd_lockstruct.ls_jid;
1138                 sdp->sd_lockstruct.ls_jid = 0;
1139                 goto fail_sb;
1140         }
1141
1142         if (sdp->sd_args.ar_spectator)
1143                 snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.s",
1144                          sdp->sd_table_name);
1145         else
1146                 snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.%u",
1147                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1148
1149         error = init_inodes(sdp, DO);
1150         if (error)
1151                 goto fail_sb;
1152
1153         error = init_per_node(sdp, DO);
1154         if (error)
1155                 goto fail_inodes;
1156
1157         error = gfs2_statfs_init(sdp);
1158         if (error) {
1159                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1160                 goto fail_per_node;
1161         }
1162
1163         if (!sb_rdonly(sb)) {
1164                 error = gfs2_make_fs_rw(sdp);
1165                 if (error) {
1166                         fs_err(sdp, "can't make FS RW: %d\n", error);
1167                         goto fail_per_node;
1168                 }
1169         }
1170
1171         gfs2_glock_dq_uninit(&mount_gh);
1172         gfs2_online_uevent(sdp);
1173         return 0;
1174
1175 fail_per_node:
1176         init_per_node(sdp, UNDO);
1177 fail_inodes:
1178         init_inodes(sdp, UNDO);
1179 fail_sb:
1180         if (sdp->sd_root_dir)
1181                 dput(sdp->sd_root_dir);
1182         if (sdp->sd_master_dir)
1183                 dput(sdp->sd_master_dir);
1184         if (sb->s_root)
1185                 dput(sb->s_root);
1186         sb->s_root = NULL;
1187 fail_locking:
1188         init_locking(sdp, &mount_gh, UNDO);
1189 fail_lm:
1190         complete_all(&sdp->sd_journal_ready);
1191         gfs2_gl_hash_clear(sdp);
1192         gfs2_lm_unmount(sdp);
1193 fail_debug:
1194         gfs2_delete_debugfs_file(sdp);
1195         free_percpu(sdp->sd_lkstats);
1196         /* gfs2_sys_fs_del must be the last thing we do, since it causes
1197          * sysfs to call function gfs2_sbd_release, which frees sdp. */
1198         gfs2_sys_fs_del(sdp);
1199         sb->s_fs_info = NULL;
1200         return error;
1201 }
1202
1203 static int set_gfs2_super(struct super_block *s, void *data)
1204 {
1205         s->s_bdev = data;
1206         s->s_dev = s->s_bdev->bd_dev;
1207         s->s_bdi = bdi_get(s->s_bdev->bd_bdi);
1208         return 0;
1209 }
1210
1211 static int test_gfs2_super(struct super_block *s, void *ptr)
1212 {
1213         struct block_device *bdev = ptr;
1214         return (bdev == s->s_bdev);
1215 }
1216
1217 /**
1218  * gfs2_mount - Get the GFS2 superblock
1219  * @fs_type: The GFS2 filesystem type
1220  * @flags: Mount flags
1221  * @dev_name: The name of the device
1222  * @data: The mount arguments
1223  *
1224  * Q. Why not use get_sb_bdev() ?
1225  * A. We need to select one of two root directories to mount, independent
1226  *    of whether this is the initial, or subsequent, mount of this sb
1227  *
1228  * Returns: 0 or -ve on error
1229  */
1230
1231 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1232                        const char *dev_name, void *data)
1233 {
1234         struct block_device *bdev;
1235         struct super_block *s;
1236         fmode_t mode = FMODE_READ | FMODE_EXCL;
1237         int error;
1238         struct gfs2_args args;
1239         struct gfs2_sbd *sdp;
1240
1241         if (!(flags & SB_RDONLY))
1242                 mode |= FMODE_WRITE;
1243
1244         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1245         if (IS_ERR(bdev))
1246                 return ERR_CAST(bdev);
1247
1248         /*
1249          * once the super is inserted into the list by sget, s_umount
1250          * will protect the lockfs code from trying to start a snapshot
1251          * while we are mounting
1252          */
1253         mutex_lock(&bdev->bd_fsfreeze_mutex);
1254         if (bdev->bd_fsfreeze_count > 0) {
1255                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1256                 error = -EBUSY;
1257                 goto error_bdev;
1258         }
1259         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1260         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1261         error = PTR_ERR(s);
1262         if (IS_ERR(s))
1263                 goto error_bdev;
1264
1265         if (s->s_root) {
1266                 /*
1267                  * s_umount nests inside bd_mutex during
1268                  * __invalidate_device().  blkdev_put() acquires
1269                  * bd_mutex and can't be called under s_umount.  Drop
1270                  * s_umount temporarily.  This is safe as we're
1271                  * holding an active reference.
1272                  */
1273                 up_write(&s->s_umount);
1274                 blkdev_put(bdev, mode);
1275                 down_write(&s->s_umount);
1276         } else {
1277                 /* s_mode must be set before deactivate_locked_super calls */
1278                 s->s_mode = mode;
1279         }
1280
1281         memset(&args, 0, sizeof(args));
1282         args.ar_quota = GFS2_QUOTA_DEFAULT;
1283         args.ar_data = GFS2_DATA_DEFAULT;
1284         args.ar_commit = 30;
1285         args.ar_statfs_quantum = 30;
1286         args.ar_quota_quantum = 60;
1287         args.ar_errors = GFS2_ERRORS_DEFAULT;
1288
1289         error = gfs2_mount_args(&args, data);
1290         if (error) {
1291                 pr_warn("can't parse mount arguments\n");
1292                 goto error_super;
1293         }
1294
1295         if (s->s_root) {
1296                 error = -EBUSY;
1297                 if ((flags ^ s->s_flags) & SB_RDONLY)
1298                         goto error_super;
1299         } else {
1300                 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1301                 sb_set_blocksize(s, block_size(bdev));
1302                 error = fill_super(s, &args, flags & SB_SILENT ? 1 : 0);
1303                 if (error)
1304                         goto error_super;
1305                 s->s_flags |= SB_ACTIVE;
1306                 bdev->bd_super = s;
1307         }
1308
1309         sdp = s->s_fs_info;
1310         if (args.ar_meta)
1311                 return dget(sdp->sd_master_dir);
1312         else
1313                 return dget(sdp->sd_root_dir);
1314
1315 error_super:
1316         deactivate_locked_super(s);
1317         return ERR_PTR(error);
1318 error_bdev:
1319         blkdev_put(bdev, mode);
1320         return ERR_PTR(error);
1321 }
1322
1323 static int set_meta_super(struct super_block *s, void *ptr)
1324 {
1325         return -EINVAL;
1326 }
1327
1328 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1329                         int flags, const char *dev_name, void *data)
1330 {
1331         struct super_block *s;
1332         struct gfs2_sbd *sdp;
1333         struct path path;
1334         int error;
1335
1336         if (!dev_name || !*dev_name)
1337                 return ERR_PTR(-EINVAL);
1338
1339         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1340         if (error) {
1341                 pr_warn("path_lookup on %s returned error %d\n",
1342                         dev_name, error);
1343                 return ERR_PTR(error);
1344         }
1345         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1346                  path.dentry->d_sb->s_bdev);
1347         path_put(&path);
1348         if (IS_ERR(s)) {
1349                 pr_warn("gfs2 mount does not exist\n");
1350                 return ERR_CAST(s);
1351         }
1352         if ((flags ^ s->s_flags) & SB_RDONLY) {
1353                 deactivate_locked_super(s);
1354                 return ERR_PTR(-EBUSY);
1355         }
1356         sdp = s->s_fs_info;
1357         return dget(sdp->sd_master_dir);
1358 }
1359
1360 static void gfs2_kill_sb(struct super_block *sb)
1361 {
1362         struct gfs2_sbd *sdp = sb->s_fs_info;
1363
1364         if (sdp == NULL) {
1365                 kill_block_super(sb);
1366                 return;
1367         }
1368
1369         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SYNC | GFS2_LFC_KILL_SB);
1370         dput(sdp->sd_root_dir);
1371         dput(sdp->sd_master_dir);
1372         sdp->sd_root_dir = NULL;
1373         sdp->sd_master_dir = NULL;
1374         shrink_dcache_sb(sb);
1375         free_percpu(sdp->sd_lkstats);
1376         kill_block_super(sb);
1377 }
1378
1379 struct file_system_type gfs2_fs_type = {
1380         .name = "gfs2",
1381         .fs_flags = FS_REQUIRES_DEV,
1382         .mount = gfs2_mount,
1383         .kill_sb = gfs2_kill_sb,
1384         .owner = THIS_MODULE,
1385 };
1386 MODULE_ALIAS_FS("gfs2");
1387
1388 struct file_system_type gfs2meta_fs_type = {
1389         .name = "gfs2meta",
1390         .fs_flags = FS_REQUIRES_DEV,
1391         .mount = gfs2_mount_meta,
1392         .owner = THIS_MODULE,
1393 };
1394 MODULE_ALIAS_FS("gfs2meta");