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  * Created by Gao Xiang <[email protected]>
   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 struct page *erofs_read_inode(struct inode *inode,
  17                                      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         struct page *page;
  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         page = erofs_get_meta_page(sb, blkaddr);
  38         if (IS_ERR(page)) {
  39                 erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
  40                           vi->nid, PTR_ERR(page));
  41                 return page;
  42         }
  43
  44         dic = page_address(page) + *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 inode acrosses page boundary */
  66                 if (*ofs + vi->inode_isize <= PAGE_SIZE) {
  67                         *ofs += vi->inode_isize;
  68                         die = (struct erofs_inode_extended *)dic;
  69                 } else {
  70                         const unsigned int gotten = PAGE_SIZE - *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                         unlock_page(page);
  79                         put_page(page);
  80
  81                         page = erofs_get_meta_page(sb, blkaddr + 1);
  82                         if (IS_ERR(page)) {
  83                                 erofs_err(sb, "failed to get inode payload page (nid: %llu), err %ld",
  84                                           vi->nid, PTR_ERR(page));
  85                                 kfree(copied);
  86                                 return page;
  87                         }
  88                         *ofs = vi->inode_isize - gotten;
  89                         memcpy((u8 *)copied + gotten, page_address(page), *ofs);
  90                         die = copied;
  91                 }
  92                 vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
  93
  94                 inode->i_mode = le16_to_cpu(die->i_mode);
  95                 switch (inode->i_mode & S_IFMT) {
  96                 case S_IFREG:
  97                 case S_IFDIR:
  98                 case S_IFLNK:
  99                         vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
 100                         break;
 101                 case S_IFCHR:
 102                 case S_IFBLK:
 103                         inode->i_rdev =
 104                                 new_decode_dev(le32_to_cpu(die->i_u.rdev));
 105                         break;
 106                 case S_IFIFO:
 107                 case S_IFSOCK:
 108                         inode->i_rdev = 0;
 109                         break;
 110                 default:
 111                         goto bogusimode;
 112                 }
 113                 i_uid_write(inode, le32_to_cpu(die->i_uid));
 114                 i_gid_write(inode, le32_to_cpu(die->i_gid));
 115                 set_nlink(inode, le32_to_cpu(die->i_nlink));
 116
 117                 /* extended inode has its own timestamp */
 118                 inode->i_ctime.tv_sec = le64_to_cpu(die->i_ctime);
 119                 inode->i_ctime.tv_nsec = le32_to_cpu(die->i_ctime_nsec);
 120
 121                 inode->i_size = le64_to_cpu(die->i_size);
 122
 123                 /* total blocks for compressed files */
 124                 if (erofs_inode_is_data_compressed(vi->datalayout))
 125                         nblks = le32_to_cpu(die->i_u.compressed_blocks);
 126
 127                 kfree(copied);
 128                 break;
 129         case EROFS_INODE_LAYOUT_COMPACT:
 130                 vi->inode_isize = sizeof(struct erofs_inode_compact);
 131                 *ofs += vi->inode_isize;
 132                 vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
 133
 134                 inode->i_mode = le16_to_cpu(dic->i_mode);
 135                 switch (inode->i_mode & S_IFMT) {
 136                 case S_IFREG:
 137                 case S_IFDIR:
 138                 case S_IFLNK:
 139                         vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
 140                         break;
 141                 case S_IFCHR:
 142                 case S_IFBLK:
 143                         inode->i_rdev =
 144                                 new_decode_dev(le32_to_cpu(dic->i_u.rdev));
 145                         break;
 146                 case S_IFIFO:
 147                 case S_IFSOCK:
 148                         inode->i_rdev = 0;
 149                         break;
 150                 default:
 151                         goto bogusimode;
 152                 }
 153                 i_uid_write(inode, le16_to_cpu(dic->i_uid));
 154                 i_gid_write(inode, le16_to_cpu(dic->i_gid));
 155                 set_nlink(inode, le16_to_cpu(dic->i_nlink));
 156
 157                 /* use build time for compact inodes */
 158                 inode->i_ctime.tv_sec = sbi->build_time;
 159                 inode->i_ctime.tv_nsec = sbi->build_time_nsec;
 160
 161                 inode->i_size = le32_to_cpu(dic->i_size);
 162                 if (erofs_inode_is_data_compressed(vi->datalayout))
 163                         nblks = le32_to_cpu(dic->i_u.compressed_blocks);
 164                 break;
 165         default:
 166                 erofs_err(inode->i_sb,
 167                           "unsupported on-disk inode version %u of nid %llu",
 168                           erofs_inode_version(ifmt), vi->nid);
 169                 err = -EOPNOTSUPP;
 170                 goto err_out;
 171         }
 172
 173         inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
 174         inode->i_atime.tv_sec = inode->i_ctime.tv_sec;
 175         inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
 176         inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
 177
 178         if (!nblks)
 179                 /* measure inode.i_blocks as generic filesystems */
 180                 inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
 181         else
 182                 inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
 183         return page;
 184
 185 bogusimode:
 186         erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
 187                   inode->i_mode, vi->nid);
 188         err = -EFSCORRUPTED;
 189 err_out:
 190         DBG_BUGON(1);
 191         kfree(copied);
 192         unlock_page(page);
 193         put_page(page);
 194         return ERR_PTR(err);
 195 }
 196
 197 static int erofs_fill_symlink(struct inode *inode, void *data,
 198                               unsigned int m_pofs)
 199 {
 200         struct erofs_inode *vi = EROFS_I(inode);
 201         char *lnk;
 202
 203         /* if it cannot be handled with fast symlink scheme */
 204         if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
 205             inode->i_size >= PAGE_SIZE) {
 206                 inode->i_op = &erofs_symlink_iops;
 207                 return 0;
 208         }
 209
 210         lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
 211         if (!lnk)
 212                 return -ENOMEM;
 213
 214         m_pofs += vi->xattr_isize;
 215         /* inline symlink data shouldn't cross page boundary as well */
 216         if (m_pofs + inode->i_size > PAGE_SIZE) {
 217                 kfree(lnk);
 218                 erofs_err(inode->i_sb,
 219                           "inline data cross block boundary @ nid %llu",
 220                           vi->nid);
 221                 DBG_BUGON(1);
 222                 return -EFSCORRUPTED;
 223         }
 224
 225         memcpy(lnk, data + m_pofs, inode->i_size);
 226         lnk[inode->i_size] = '\0';
 227
 228         inode->i_link = lnk;
 229         inode->i_op = &erofs_fast_symlink_iops;
 230         return 0;
 231 }
 232
 233 static int erofs_fill_inode(struct inode *inode, int isdir)
 234 {
 235         struct erofs_inode *vi = EROFS_I(inode);
 236         struct page *page;
 237         unsigned int ofs;
 238         int err = 0;
 239
 240         trace_erofs_fill_inode(inode, isdir);
 241
 242         /* read inode base data from disk */
 243         page = erofs_read_inode(inode, &ofs);
 244         if (IS_ERR(page))
 245                 return PTR_ERR(page);
 246
 247         /* setup the new inode */
 248         switch (inode->i_mode & S_IFMT) {
 249         case S_IFREG:
 250                 inode->i_op = &erofs_generic_iops;
 251                 inode->i_fop = &generic_ro_fops;
 252                 break;
 253         case S_IFDIR:
 254                 inode->i_op = &erofs_dir_iops;
 255                 inode->i_fop = &erofs_dir_fops;
 256                 break;
 257         case S_IFLNK:
 258                 err = erofs_fill_symlink(inode, page_address(page), ofs);
 259                 if (err)
 260                         goto out_unlock;
 261                 inode_nohighmem(inode);
 262                 break;
 263         case S_IFCHR:
 264         case S_IFBLK:
 265         case S_IFIFO:
 266         case S_IFSOCK:
 267                 inode->i_op = &erofs_generic_iops;
 268                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 269                 goto out_unlock;
 270         default:
 271                 err = -EFSCORRUPTED;
 272                 goto out_unlock;
 273         }
 274
 275         if (erofs_inode_is_data_compressed(vi->datalayout)) {
 276                 err = z_erofs_fill_inode(inode);
 277                 goto out_unlock;
 278         }
 279         inode->i_mapping->a_ops = &erofs_raw_access_aops;
 280
 281 out_unlock:
 282         unlock_page(page);
 283         put_page(page);
 284         return err;
 285 }
 286
 287 /*
 288  * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
 289  * we should do more for 32-bit platform to find the right inode.
 290  */
 291 static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
 292 {
 293         const erofs_nid_t nid = *(erofs_nid_t *)opaque;
 294
 295         return EROFS_I(inode)->nid == nid;
 296 }
 297
 298 static int erofs_iget_set_actor(struct inode *inode, void *opaque)
 299 {
 300         const erofs_nid_t nid = *(erofs_nid_t *)opaque;
 301
 302         inode->i_ino = erofs_inode_hash(nid);
 303         return 0;
 304 }
 305
 306 static inline struct inode *erofs_iget_locked(struct super_block *sb,
 307                                               erofs_nid_t nid)
 308 {
 309         const unsigned long hashval = erofs_inode_hash(nid);
 310
 311         return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
 312                 erofs_iget_set_actor, &nid);
 313 }
 314
 315 struct inode *erofs_iget(struct super_block *sb,
 316                          erofs_nid_t nid,
 317                          bool isdir)
 318 {
 319         struct inode *inode = erofs_iget_locked(sb, nid);
 320
 321         if (!inode)
 322                 return ERR_PTR(-ENOMEM);
 323
 324         if (inode->i_state & I_NEW) {
 325                 int err;
 326                 struct erofs_inode *vi = EROFS_I(inode);
 327
 328                 vi->nid = nid;
 329
 330                 err = erofs_fill_inode(inode, isdir);
 331                 if (!err)
 332                         unlock_new_inode(inode);
 333                 else {
 334                         iget_failed(inode);
 335                         inode = ERR_PTR(err);
 336                 }
 337         }
 338         return inode;
 339 }
 340
 341 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 342                   struct kstat *stat, u32 request_mask,
 343                   unsigned int query_flags)
 344 {
 345         struct inode *const inode = d_inode(path->dentry);
 346
 347         if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
 348                 stat->attributes |= STATX_ATTR_COMPRESSED;
 349
 350         stat->attributes |= STATX_ATTR_IMMUTABLE;
 351         stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
 352                                   STATX_ATTR_IMMUTABLE);
 353
 354         generic_fillattr(&init_user_ns, inode, stat);
 355         return 0;
 356 }
 357
 358 const struct inode_operations erofs_generic_iops = {
 359         .getattr = erofs_getattr,
 360         .listxattr = erofs_listxattr,
 361         .get_acl = erofs_get_acl,
 362 };
 363
 364 const struct inode_operations erofs_symlink_iops = {
 365         .get_link = page_get_link,
 366         .getattr = erofs_getattr,
 367         .listxattr = erofs_listxattr,
 368         .get_acl = erofs_get_acl,
 369 };
 370
 371 const struct inode_operations erofs_fast_symlink_iops = {
 372         .get_link = simple_get_link,
 373         .getattr = erofs_getattr,
 374         .listxattr = erofs_listxattr,
 375         .get_acl = erofs_get_acl,
 376 };
 377