fs/erofs/inode.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2017-2018 HUAWEI, Inc.
   4  *             https://www.huawei.com/
   5  * Copyright (C) 2021, Alibaba Cloud
   6  */
   7 #include "xattr.h"
   8
   9 #include <trace/events/erofs.h>
  10
  11 /*
  12  * if inode is successfully read, return its inode page (or sometimes
  13  * the inode payload page if it's an extended inode) in order to fill
  14  * inline data if possible.
  15  */
  16 static void *erofs_read_inode(struct erofs_buf *buf,
  17                               struct inode *inode, unsigned int *ofs)
  18 {
  19         struct super_block *sb = inode->i_sb;
  20         struct erofs_sb_info *sbi = EROFS_SB(sb);
  21         struct erofs_inode *vi = EROFS_I(inode);
  22         const erofs_off_t inode_loc = iloc(sbi, vi->nid);
  23
  24         erofs_blk_t blkaddr, nblks = 0;
  25         void *kaddr;
  26         struct erofs_inode_compact *dic;
  27         struct erofs_inode_extended *die, *copied = NULL;
  28         unsigned int ifmt;
  29         int err;
  30
  31         blkaddr = erofs_blknr(inode_loc);
  32         *ofs = erofs_blkoff(inode_loc);
  33
  34         erofs_dbg("%s, reading inode nid %llu at %u of blkaddr %u",
  35                   __func__, vi->nid, *ofs, blkaddr);
  36
  37         kaddr = erofs_read_metabuf(buf, sb, blkaddr, EROFS_KMAP);
  38         if (IS_ERR(kaddr)) {
  39                 erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
  40                           vi->nid, PTR_ERR(kaddr));
  41                 return kaddr;
  42         }
  43
  44         dic = kaddr + *ofs;
  45         ifmt = le16_to_cpu(dic->i_format);
  46
  47         if (ifmt & ~EROFS_I_ALL) {
  48                 erofs_err(inode->i_sb, "unsupported i_format %u of nid %llu",
  49                           ifmt, vi->nid);
  50                 err = -EOPNOTSUPP;
  51                 goto err_out;
  52         }
  53
  54         vi->datalayout = erofs_inode_datalayout(ifmt);
  55         if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
  56                 erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",
  57                           vi->datalayout, vi->nid);
  58                 err = -EOPNOTSUPP;
  59                 goto err_out;
  60         }
  61
  62         switch (erofs_inode_version(ifmt)) {
  63         case EROFS_INODE_LAYOUT_EXTENDED:
  64                 vi->inode_isize = sizeof(struct erofs_inode_extended);
  65                 /* check if the extended inode acrosses block boundary */
  66                 if (*ofs + vi->inode_isize <= EROFS_BLKSIZ) {
  67                         *ofs += vi->inode_isize;
  68                         die = (struct erofs_inode_extended *)dic;
  69                 } else {
  70                         const unsigned int gotten = EROFS_BLKSIZ - *ofs;
  71
  72                         copied = kmalloc(vi->inode_isize, GFP_NOFS);
  73                         if (!copied) {
  74                                 err = -ENOMEM;
  75                                 goto err_out;
  76                         }
  77                         memcpy(copied, dic, gotten);
  78                         kaddr = erofs_read_metabuf(buf, sb, blkaddr + 1,
  79                                                    EROFS_KMAP);
  80                         if (IS_ERR(kaddr)) {
  81                                 erofs_err(sb, "failed to get inode payload block (nid: %llu), err %ld",
  82                                           vi->nid, PTR_ERR(kaddr));
  83                                 kfree(copied);
  84                                 return kaddr;
  85                         }
  86                         *ofs = vi->inode_isize - gotten;
  87                         memcpy((u8 *)copied + gotten, kaddr, *ofs);
  88                         die = copied;
  89                 }
  90                 vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
  91
  92                 inode->i_mode = le16_to_cpu(die->i_mode);
  93                 switch (inode->i_mode & S_IFMT) {
  94                 case S_IFREG:
  95                 case S_IFDIR:
  96                 case S_IFLNK:
  97                         vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
  98                         break;
  99                 case S_IFCHR:
 100                 case S_IFBLK:
 101                         inode->i_rdev =
 102                                 new_decode_dev(le32_to_cpu(die->i_u.rdev));
 103                         break;
 104                 case S_IFIFO:
 105                 case S_IFSOCK:
 106                         inode->i_rdev = 0;
 107                         break;
 108                 default:
 109                         goto bogusimode;
 110                 }
 111                 i_uid_write(inode, le32_to_cpu(die->i_uid));
 112                 i_gid_write(inode, le32_to_cpu(die->i_gid));
 113                 set_nlink(inode, le32_to_cpu(die->i_nlink));
 114
 115                 /* extended inode has its own timestamp */
 116                 inode->i_ctime.tv_sec = le64_to_cpu(die->i_ctime);
 117                 inode->i_ctime.tv_nsec = le32_to_cpu(die->i_ctime_nsec);
 118
 119                 inode->i_size = le64_to_cpu(die->i_size);
 120
 121                 /* total blocks for compressed files */
 122                 if (erofs_inode_is_data_compressed(vi->datalayout))
 123                         nblks = le32_to_cpu(die->i_u.compressed_blocks);
 124                 else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
 125                         /* fill chunked inode summary info */
 126                         vi->chunkformat = le16_to_cpu(die->i_u.c.format);
 127                 kfree(copied);
 128                 copied = NULL;
 129                 break;
 130         case EROFS_INODE_LAYOUT_COMPACT:
 131                 vi->inode_isize = sizeof(struct erofs_inode_compact);
 132                 *ofs += vi->inode_isize;
 133                 vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
 134
 135                 inode->i_mode = le16_to_cpu(dic->i_mode);
 136                 switch (inode->i_mode & S_IFMT) {
 137                 case S_IFREG:
 138                 case S_IFDIR:
 139                 case S_IFLNK:
 140                         vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
 141                         break;
 142                 case S_IFCHR:
 143                 case S_IFBLK:
 144                         inode->i_rdev =
 145                                 new_decode_dev(le32_to_cpu(dic->i_u.rdev));
 146                         break;
 147                 case S_IFIFO:
 148                 case S_IFSOCK:
 149                         inode->i_rdev = 0;
 150                         break;
 151                 default:
 152                         goto bogusimode;
 153                 }
 154                 i_uid_write(inode, le16_to_cpu(dic->i_uid));
 155                 i_gid_write(inode, le16_to_cpu(dic->i_gid));
 156                 set_nlink(inode, le16_to_cpu(dic->i_nlink));
 157
 158                 /* use build time for compact inodes */
 159                 inode->i_ctime.tv_sec = sbi->build_time;
 160                 inode->i_ctime.tv_nsec = sbi->build_time_nsec;
 161
 162                 inode->i_size = le32_to_cpu(dic->i_size);
 163                 if (erofs_inode_is_data_compressed(vi->datalayout))
 164                         nblks = le32_to_cpu(dic->i_u.compressed_blocks);
 165                 else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
 166                         vi->chunkformat = le16_to_cpu(dic->i_u.c.format);
 167                 break;
 168         default:
 169                 erofs_err(inode->i_sb,
 170                           "unsupported on-disk inode version %u of nid %llu",
 171                           erofs_inode_version(ifmt), vi->nid);
 172                 err = -EOPNOTSUPP;
 173                 goto err_out;
 174         }
 175
 176         if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
 177                 if (vi->chunkformat & ~EROFS_CHUNK_FORMAT_ALL) {
 178                         erofs_err(inode->i_sb,
 179                                   "unsupported chunk format %x of nid %llu",
 180                                   vi->chunkformat, vi->nid);
 181                         err = -EOPNOTSUPP;
 182                         goto err_out;
 183                 }
 184                 vi->chunkbits = LOG_BLOCK_SIZE +
 185                         (vi->chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
 186         }
 187         inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
 188         inode->i_atime.tv_sec = inode->i_ctime.tv_sec;
 189         inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
 190         inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
 191
 192         inode->i_flags &= ~S_DAX;
 193         if (test_opt(&sbi->opt, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
 194             vi->datalayout == EROFS_INODE_FLAT_PLAIN)
 195                 inode->i_flags |= S_DAX;
 196         if (!nblks)
 197                 /* measure inode.i_blocks as generic filesystems */
 198                 inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
 199         else
 200                 inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
 201         return kaddr;
 202
 203 bogusimode:
 204         erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
 205                   inode->i_mode, vi->nid);
 206         err = -EFSCORRUPTED;
 207 err_out:
 208         DBG_BUGON(1);
 209         kfree(copied);
 210         erofs_put_metabuf(buf);
 211         return ERR_PTR(err);
 212 }
 213
 214 static int erofs_fill_symlink(struct inode *inode, void *kaddr,
 215                               unsigned int m_pofs)
 216 {
 217         struct erofs_inode *vi = EROFS_I(inode);
 218         char *lnk;
 219
 220         /* if it cannot be handled with fast symlink scheme */
 221         if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
 222             inode->i_size >= EROFS_BLKSIZ) {
 223                 inode->i_op = &erofs_symlink_iops;
 224                 return 0;
 225         }
 226
 227         lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
 228         if (!lnk)
 229                 return -ENOMEM;
 230
 231         m_pofs += vi->xattr_isize;
 232         /* inline symlink data shouldn't cross block boundary */
 233         if (m_pofs + inode->i_size > EROFS_BLKSIZ) {
 234                 kfree(lnk);
 235                 erofs_err(inode->i_sb,
 236                           "inline data cross block boundary @ nid %llu",
 237                           vi->nid);
 238                 DBG_BUGON(1);
 239                 return -EFSCORRUPTED;
 240         }
 241         memcpy(lnk, kaddr + m_pofs, inode->i_size);
 242         lnk[inode->i_size] = '\0';
 243
 244         inode->i_link = lnk;
 245         inode->i_op = &erofs_fast_symlink_iops;
 246         return 0;
 247 }
 248
 249 static int erofs_fill_inode(struct inode *inode, int isdir)
 250 {
 251         struct erofs_inode *vi = EROFS_I(inode);
 252         struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
 253         void *kaddr;
 254         unsigned int ofs;
 255         int err = 0;
 256
 257         trace_erofs_fill_inode(inode, isdir);
 258
 259         /* read inode base data from disk */
 260         kaddr = erofs_read_inode(&buf, inode, &ofs);
 261         if (IS_ERR(kaddr))
 262                 return PTR_ERR(kaddr);
 263
 264         /* setup the new inode */
 265         switch (inode->i_mode & S_IFMT) {
 266         case S_IFREG:
 267                 inode->i_op = &erofs_generic_iops;
 268                 if (erofs_inode_is_data_compressed(vi->datalayout))
 269                         inode->i_fop = &generic_ro_fops;
 270                 else
 271                         inode->i_fop = &erofs_file_fops;
 272                 break;
 273         case S_IFDIR:
 274                 inode->i_op = &erofs_dir_iops;
 275                 inode->i_fop = &erofs_dir_fops;
 276                 break;
 277         case S_IFLNK:
 278                 err = erofs_fill_symlink(inode, kaddr, ofs);
 279                 if (err)
 280                         goto out_unlock;
 281                 inode_nohighmem(inode);
 282                 break;
 283         case S_IFCHR:
 284         case S_IFBLK:
 285         case S_IFIFO:
 286         case S_IFSOCK:
 287                 inode->i_op = &erofs_generic_iops;
 288                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 289                 goto out_unlock;
 290         default:
 291                 err = -EFSCORRUPTED;
 292                 goto out_unlock;
 293         }
 294
 295         if (erofs_inode_is_data_compressed(vi->datalayout)) {
 296                 err = z_erofs_fill_inode(inode);
 297                 goto out_unlock;
 298         }
 299         inode->i_mapping->a_ops = &erofs_raw_access_aops;
 300
 301 out_unlock:
 302         erofs_put_metabuf(&buf);
 303         return err;
 304 }
 305
 306 /*
 307  * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
 308  * we should do more for 32-bit platform to find the right inode.
 309  */
 310 static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
 311 {
 312         const erofs_nid_t nid = *(erofs_nid_t *)opaque;
 313
 314         return EROFS_I(inode)->nid == nid;
 315 }
 316
 317 static int erofs_iget_set_actor(struct inode *inode, void *opaque)
 318 {
 319         const erofs_nid_t nid = *(erofs_nid_t *)opaque;
 320
 321         inode->i_ino = erofs_inode_hash(nid);
 322         return 0;
 323 }
 324
 325 static inline struct inode *erofs_iget_locked(struct super_block *sb,
 326                                               erofs_nid_t nid)
 327 {
 328         const unsigned long hashval = erofs_inode_hash(nid);
 329
 330         return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
 331                 erofs_iget_set_actor, &nid);
 332 }
 333
 334 struct inode *erofs_iget(struct super_block *sb,
 335                          erofs_nid_t nid,
 336                          bool isdir)
 337 {
 338         struct inode *inode = erofs_iget_locked(sb, nid);
 339
 340         if (!inode)
 341                 return ERR_PTR(-ENOMEM);
 342
 343         if (inode->i_state & I_NEW) {
 344                 int err;
 345                 struct erofs_inode *vi = EROFS_I(inode);
 346
 347                 vi->nid = nid;
 348
 349                 err = erofs_fill_inode(inode, isdir);
 350                 if (!err)
 351                         unlock_new_inode(inode);
 352                 else {
 353                         iget_failed(inode);
 354                         inode = ERR_PTR(err);
 355                 }
 356         }
 357         return inode;
 358 }
 359
 360 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 361                   struct kstat *stat, u32 request_mask,
 362                   unsigned int query_flags)
 363 {
 364         struct inode *const inode = d_inode(path->dentry);
 365
 366         if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
 367                 stat->attributes |= STATX_ATTR_COMPRESSED;
 368
 369         stat->attributes |= STATX_ATTR_IMMUTABLE;
 370         stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
 371                                   STATX_ATTR_IMMUTABLE);
 372
 373         generic_fillattr(&init_user_ns, inode, stat);
 374         return 0;
 375 }
 376
 377 const struct inode_operations erofs_generic_iops = {
 378         .getattr = erofs_getattr,
 379         .listxattr = erofs_listxattr,
 380         .get_acl = erofs_get_acl,
 381         .fiemap = erofs_fiemap,
 382 };
 383
 384 const struct inode_operations erofs_symlink_iops = {
 385         .get_link = page_get_link,
 386         .getattr = erofs_getattr,
 387         .listxattr = erofs_listxattr,
 388         .get_acl = erofs_get_acl,
 389 };
 390
 391 const struct inode_operations erofs_fast_symlink_iops = {
 392         .get_link = simple_get_link,
 393         .getattr = erofs_getattr,
 394         .listxattr = erofs_listxattr,
 395         .get_acl = erofs_get_acl,
 396 };