fs/erofs/inode.c

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