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