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         vi->datalayout = erofs_inode_datalayout(ifmt);
  48         if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
  49                 erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",
  50                           vi->datalayout, vi->nid);
  51                 err = -EOPNOTSUPP;
  52                 goto err_out;
  53         }
  54
  55         switch (erofs_inode_version(ifmt)) {
  56         case EROFS_INODE_LAYOUT_EXTENDED:
  57                 vi->inode_isize = sizeof(struct erofs_inode_extended);
  58                 /* check if the inode acrosses page boundary */
  59                 if (*ofs + vi->inode_isize <= PAGE_SIZE) {
  60                         *ofs += vi->inode_isize;
  61                         die = (struct erofs_inode_extended *)dic;
  62                 } else {
  63                         const unsigned int gotten = PAGE_SIZE - *ofs;
  64
  65                         copied = kmalloc(vi->inode_isize, GFP_NOFS);
  66                         if (!copied) {
  67                                 err = -ENOMEM;
  68                                 goto err_out;
  69                         }
  70                         memcpy(copied, dic, gotten);
  71                         unlock_page(page);
  72                         put_page(page);
  73
  74                         page = erofs_get_meta_page(sb, blkaddr + 1);
  75                         if (IS_ERR(page)) {
  76                                 erofs_err(sb, "failed to get inode payload page (nid: %llu), err %ld",
  77                                           vi->nid, PTR_ERR(page));
  78                                 kfree(copied);
  79                                 return page;
  80                         }
  81                         *ofs = vi->inode_isize - gotten;
  82                         memcpy((u8 *)copied + gotten, page_address(page), *ofs);
  83                         die = copied;
  84                 }
  85                 vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
  86
  87                 inode->i_mode = le16_to_cpu(die->i_mode);
  88                 switch (inode->i_mode & S_IFMT) {
  89                 case S_IFREG:
  90                 case S_IFDIR:
  91                 case S_IFLNK:
  92                         vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
  93                         break;
  94                 case S_IFCHR:
  95                 case S_IFBLK:
  96                         inode->i_rdev =
  97                                 new_decode_dev(le32_to_cpu(die->i_u.rdev));
  98                         break;
  99                 case S_IFIFO:
 100                 case S_IFSOCK:
 101                         inode->i_rdev = 0;
 102                         break;
 103                 default:
 104                         goto bogusimode;
 105                 }
 106                 i_uid_write(inode, le32_to_cpu(die->i_uid));
 107                 i_gid_write(inode, le32_to_cpu(die->i_gid));
 108                 set_nlink(inode, le32_to_cpu(die->i_nlink));
 109
 110                 /* extended inode has its own timestamp */
 111                 inode->i_ctime.tv_sec = le64_to_cpu(die->i_ctime);
 112                 inode->i_ctime.tv_nsec = le32_to_cpu(die->i_ctime_nsec);
 113
 114                 inode->i_size = le64_to_cpu(die->i_size);
 115
 116                 /* total blocks for compressed files */
 117                 if (erofs_inode_is_data_compressed(vi->datalayout))
 118                         nblks = le32_to_cpu(die->i_u.compressed_blocks);
 119
 120                 kfree(copied);
 121                 break;
 122         case EROFS_INODE_LAYOUT_COMPACT:
 123                 vi->inode_isize = sizeof(struct erofs_inode_compact);
 124                 *ofs += vi->inode_isize;
 125                 vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
 126
 127                 inode->i_mode = le16_to_cpu(dic->i_mode);
 128                 switch (inode->i_mode & S_IFMT) {
 129                 case S_IFREG:
 130                 case S_IFDIR:
 131                 case S_IFLNK:
 132                         vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
 133                         break;
 134                 case S_IFCHR:
 135                 case S_IFBLK:
 136                         inode->i_rdev =
 137                                 new_decode_dev(le32_to_cpu(dic->i_u.rdev));
 138                         break;
 139                 case S_IFIFO:
 140                 case S_IFSOCK:
 141                         inode->i_rdev = 0;
 142                         break;
 143                 default:
 144                         goto bogusimode;
 145                 }
 146                 i_uid_write(inode, le16_to_cpu(dic->i_uid));
 147                 i_gid_write(inode, le16_to_cpu(dic->i_gid));
 148                 set_nlink(inode, le16_to_cpu(dic->i_nlink));
 149
 150                 /* use build time for compact inodes */
 151                 inode->i_ctime.tv_sec = sbi->build_time;
 152                 inode->i_ctime.tv_nsec = sbi->build_time_nsec;
 153
 154                 inode->i_size = le32_to_cpu(dic->i_size);
 155                 if (erofs_inode_is_data_compressed(vi->datalayout))
 156                         nblks = le32_to_cpu(dic->i_u.compressed_blocks);
 157                 break;
 158         default:
 159                 erofs_err(inode->i_sb,
 160                           "unsupported on-disk inode version %u of nid %llu",
 161                           erofs_inode_version(ifmt), vi->nid);
 162                 err = -EOPNOTSUPP;
 163                 goto err_out;
 164         }
 165
 166         inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
 167         inode->i_atime.tv_sec = inode->i_ctime.tv_sec;
 168         inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
 169         inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
 170
 171         if (!nblks)
 172                 /* measure inode.i_blocks as generic filesystems */
 173                 inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
 174         else
 175                 inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
 176         return page;
 177
 178 bogusimode:
 179         erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
 180                   inode->i_mode, vi->nid);
 181         err = -EFSCORRUPTED;
 182 err_out:
 183         DBG_BUGON(1);
 184         kfree(copied);
 185         unlock_page(page);
 186         put_page(page);
 187         return ERR_PTR(err);
 188 }
 189
 190 static int erofs_fill_symlink(struct inode *inode, void *data,
 191                               unsigned int m_pofs)
 192 {
 193         struct erofs_inode *vi = EROFS_I(inode);
 194         char *lnk;
 195
 196         /* if it cannot be handled with fast symlink scheme */
 197         if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
 198             inode->i_size >= PAGE_SIZE) {
 199                 inode->i_op = &erofs_symlink_iops;
 200                 return 0;
 201         }
 202
 203         lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
 204         if (!lnk)
 205                 return -ENOMEM;
 206
 207         m_pofs += vi->xattr_isize;
 208         /* inline symlink data shouldn't cross page boundary as well */
 209         if (m_pofs + inode->i_size > PAGE_SIZE) {
 210                 kfree(lnk);
 211                 erofs_err(inode->i_sb,
 212                           "inline data cross block boundary @ nid %llu",
 213                           vi->nid);
 214                 DBG_BUGON(1);
 215                 return -EFSCORRUPTED;
 216         }
 217
 218         memcpy(lnk, data + m_pofs, inode->i_size);
 219         lnk[inode->i_size] = '\0';
 220
 221         inode->i_link = lnk;
 222         inode->i_op = &erofs_fast_symlink_iops;
 223         return 0;
 224 }
 225
 226 static int erofs_fill_inode(struct inode *inode, int isdir)
 227 {
 228         struct erofs_inode *vi = EROFS_I(inode);
 229         struct page *page;
 230         unsigned int ofs;
 231         int err = 0;
 232
 233         trace_erofs_fill_inode(inode, isdir);
 234
 235         /* read inode base data from disk */
 236         page = erofs_read_inode(inode, &ofs);
 237         if (IS_ERR(page))
 238                 return PTR_ERR(page);
 239
 240         /* setup the new inode */
 241         switch (inode->i_mode & S_IFMT) {
 242         case S_IFREG:
 243                 inode->i_op = &erofs_generic_iops;
 244                 inode->i_fop = &generic_ro_fops;
 245                 break;
 246         case S_IFDIR:
 247                 inode->i_op = &erofs_dir_iops;
 248                 inode->i_fop = &erofs_dir_fops;
 249                 break;
 250         case S_IFLNK:
 251                 err = erofs_fill_symlink(inode, page_address(page), ofs);
 252                 if (err)
 253                         goto out_unlock;
 254                 inode_nohighmem(inode);
 255                 break;
 256         case S_IFCHR:
 257         case S_IFBLK:
 258         case S_IFIFO:
 259         case S_IFSOCK:
 260                 inode->i_op = &erofs_generic_iops;
 261                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 262                 goto out_unlock;
 263         default:
 264                 err = -EFSCORRUPTED;
 265                 goto out_unlock;
 266         }
 267
 268         if (erofs_inode_is_data_compressed(vi->datalayout)) {
 269                 err = z_erofs_fill_inode(inode);
 270                 goto out_unlock;
 271         }
 272         inode->i_mapping->a_ops = &erofs_raw_access_aops;
 273
 274 out_unlock:
 275         unlock_page(page);
 276         put_page(page);
 277         return err;
 278 }
 279
 280 /*
 281  * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
 282  * we should do more for 32-bit platform to find the right inode.
 283  */
 284 static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
 285 {
 286         const erofs_nid_t nid = *(erofs_nid_t *)opaque;
 287
 288         return EROFS_I(inode)->nid == nid;
 289 }
 290
 291 static int erofs_iget_set_actor(struct inode *inode, void *opaque)
 292 {
 293         const erofs_nid_t nid = *(erofs_nid_t *)opaque;
 294
 295         inode->i_ino = erofs_inode_hash(nid);
 296         return 0;
 297 }
 298
 299 static inline struct inode *erofs_iget_locked(struct super_block *sb,
 300                                               erofs_nid_t nid)
 301 {
 302         const unsigned long hashval = erofs_inode_hash(nid);
 303
 304         return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
 305                 erofs_iget_set_actor, &nid);
 306 }
 307
 308 struct inode *erofs_iget(struct super_block *sb,
 309                          erofs_nid_t nid,
 310                          bool isdir)
 311 {
 312         struct inode *inode = erofs_iget_locked(sb, nid);
 313
 314         if (!inode)
 315                 return ERR_PTR(-ENOMEM);
 316
 317         if (inode->i_state & I_NEW) {
 318                 int err;
 319                 struct erofs_inode *vi = EROFS_I(inode);
 320
 321                 vi->nid = nid;
 322
 323                 err = erofs_fill_inode(inode, isdir);
 324                 if (!err)
 325                         unlock_new_inode(inode);
 326                 else {
 327                         iget_failed(inode);
 328                         inode = ERR_PTR(err);
 329                 }
 330         }
 331         return inode;
 332 }
 333
 334 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 335                   struct kstat *stat, u32 request_mask,
 336                   unsigned int query_flags)
 337 {
 338         struct inode *const inode = d_inode(path->dentry);
 339
 340         if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
 341                 stat->attributes |= STATX_ATTR_COMPRESSED;
 342
 343         stat->attributes |= STATX_ATTR_IMMUTABLE;
 344         stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
 345                                   STATX_ATTR_IMMUTABLE);
 346
 347         generic_fillattr(&init_user_ns, inode, stat);
 348         return 0;
 349 }
 350
 351 const struct inode_operations erofs_generic_iops = {
 352         .getattr = erofs_getattr,
 353         .listxattr = erofs_listxattr,
 354         .get_acl = erofs_get_acl,
 355 };
 356
 357 const struct inode_operations erofs_symlink_iops = {
 358         .get_link = page_get_link,
 359         .getattr = erofs_getattr,
 360         .listxattr = erofs_listxattr,
 361         .get_acl = erofs_get_acl,
 362 };
 363
 364 const struct inode_operations erofs_fast_symlink_iops = {
 365         .get_link = simple_get_link,
 366         .getattr = erofs_getattr,
 367         .listxattr = erofs_listxattr,
 368         .get_acl = erofs_get_acl,
 369 };
 370