ldiskfs/kernel_patches/patches/linux-5.14/ext4-kill-dx-root.patch

   1 Subject: [PATCH] linux-5.14/ext4-kill-dx-root.patch
   2
   3 ---
   4  fs/ext4/namei.c | 119 +++++++++++++++++++++++++-----------------------
   5  1 file changed, 61 insertions(+), 58 deletions(-)
   6
   7 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
   8 index e4514c9..92d29fe 100644
   9 --- a/fs/ext4/namei.c
  10 +++ b/fs/ext4/namei.c
  11 @@ -216,22 +216,13 @@ struct dx_entry
  12   * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
  13   */
  14
  15 -struct dx_root
  16 +struct dx_root_info
  17  {
  18 -       struct fake_dirent dot;
  19 -       char dot_name[4];
  20 -       struct fake_dirent dotdot;
  21 -       char dotdot_name[4];
  22 -       struct dx_root_info
  23 -       {
  24 -               __le32 reserved_zero;
  25 -               u8 hash_version;
  26 -               u8 info_length; /* 8 */
  27 -               u8 indirect_levels;
  28 -               u8 unused_flags;
  29 -       }
  30 -       info;
  31 -       struct dx_entry entries[];
  32 +       __le32 reserved_zero;
  33 +       u8 hash_version;
  34 +       u8 info_length; /* 8 */
  35 +       u8 indirect_levels;
  36 +       u8 unused_flags;
  37  };
  38
  39  struct dx_node
  40 @@ -535,6 +526,16 @@ ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
  41   * Future: use high four bits of block for coalesce-on-delete flags
  42   * Mask them off for now.
  43   */
  44 +struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de)
  45 +{
  46 +       /* get dotdot first */
  47 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
  48 +
  49 +       /* dx root info is after dotdot entry */
  50 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
  51 +
  52 +       return (struct dx_root_info *)de;
  53 +}
  54
  55  static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
  56  {
  57 @@ -780,7 +781,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
  58  {
  59         unsigned count, indirect;
  60         struct dx_entry *at, *entries, *p, *q, *m;
  61 -       struct dx_root *root;
  62 +       struct dx_root_info *info;
  63         struct dx_frame *frame = frame_in;
  64         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
  65         u32 hash;
  66 @@ -790,24 +791,24 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
  67         if (IS_ERR(frame->bh))
  68                 return (struct dx_frame *) frame->bh;
  69
  70 -       root = (struct dx_root *) frame->bh->b_data;
  71 -       if (root->info.hash_version != DX_HASH_TEA &&
  72 -           root->info.hash_version != DX_HASH_HALF_MD4 &&
  73 -           root->info.hash_version != DX_HASH_LEGACY &&
  74 -           root->info.hash_version != DX_HASH_SIPHASH) {
  75 -               ext4_warning_inode(dir,
  76 -                       "Unrecognised inode hash code %u for directory %lu",
  77 -                       root->info.hash_version, dir->i_ino);
  78 +       info = dx_get_dx_info((struct ext4_dir_entry_2 *)frame->bh->b_data);
  79 +       if (info->hash_version != DX_HASH_TEA &&
  80 +           info->hash_version != DX_HASH_HALF_MD4 &&
  81 +           info->hash_version != DX_HASH_LEGACY &&
  82 +           info->hash_version != DX_HASH_SIPHASH) {
  83 +               ext4_warning(dir->i_sb,
  84 +                       "Unrecognised inode hash code %d for directory #%lu",
  85 +                       info->hash_version, dir->i_ino);
  86                 goto fail;
  87         }
  88         if (ext4_hash_in_dirent(dir)) {
  89 -               if (root->info.hash_version != DX_HASH_SIPHASH) {
  90 +               if (info->hash_version != DX_HASH_SIPHASH) {
  91                         ext4_warning_inode(dir,
  92                                 "Hash in dirent, but hash is not SIPHASH");
  93                         goto fail;
  94                 }
  95         } else {
  96 -               if (root->info.hash_version == DX_HASH_SIPHASH) {
  97 +               if (info->hash_version == DX_HASH_SIPHASH) {
  98                         ext4_warning_inode(dir,
  99                                 "Hash code is SIPHASH, but hash not in dirent");
 100                         goto fail;
 101 @@ -815,7 +816,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
 102         }
 103         if (fname)
 104                 hinfo = &fname->hinfo;
 105 -       hinfo->hash_version = root->info.hash_version;
 106 +       hinfo->hash_version = info->hash_version;
 107         if (hinfo->hash_version <= DX_HASH_TEA)
 108                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 109         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 110 @@ -825,13 +826,13 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
 111                 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
 112         hash = hinfo->hash;
 113
 114 -       if (root->info.unused_flags & 1) {
 115 +       if (info->unused_flags & 1) {
 116                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 117 -                                  root->info.unused_flags);
 118 +                                  info->unused_flags);
 119                 goto fail;
 120         }
 121
 122 -       indirect = root->info.indirect_levels;
 123 +       indirect = info->indirect_levels;
 124         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
 125                 ext4_warning(dir->i_sb,
 126                              "Directory (ino: %lu) htree depth %#06x exceed"
 127 @@ -844,14 +845,13 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
 128                 goto fail;
 129         }
 130
 131 -       entries = (struct dx_entry *)(((char *)&root->info) +
 132 -                                     root->info.info_length);
 133 +       entries = (struct dx_entry *)(((char *)info) + info->info_length);
 134
 135         if (dx_get_limit(entries) != dx_root_limit(dir,
 136 -                                                  root->info.info_length)) {
 137 +                                                  info->info_length)) {
 138                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 139                                    dx_get_limit(entries),
 140 -                                  dx_root_limit(dir, root->info.info_length));
 141 +                                  dx_root_limit(dir, info->info_length));
 142                 goto fail;
 143         }
 144
 145 @@ -923,7 +923,7 @@ static void dx_release(struct dx_frame *frames)
 146         if (frames[0].bh == NULL)
 147                 return;
 148
 149 -       info = &((struct dx_root *)frames[0].bh->b_data)->info;
 150 +       info = dx_get_dx_info((struct ext4_dir_entry_2 *)frames[0].bh->b_data);
 151         /* save local copy, "info" may be freed after brelse() */
 152         indirect_levels = info->indirect_levels;
 153         for (i = 0; i <= indirect_levels; i++) {
 154 @@ -2181,16 +2181,15 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 155                             struct inode *inode, struct buffer_head *bh)
 156  {
 157         struct buffer_head *bh2;
 158 -       struct dx_root  *root;
 159         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
 160         struct dx_entry *entries;
 161 -       struct ext4_dir_entry_2 *de, *de2;
 162 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 163         char            *data2, *top;
 164         unsigned        len;
 165         int             retval;
 166         unsigned        blocksize;
 167         ext4_lblk_t  block;
 168 -       struct fake_dirent *fde;
 169 +       struct dx_root_info *dx_info;
 170         int csum_size = 0;
 171
 172         if (ext4_has_metadata_csum(inode->i_sb))
 173 @@ -2206,18 +2205,19 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 174                 brelse(bh);
 175                 return retval;
 176         }
 177 -       root = (struct dx_root *) bh->b_data;
 178 +
 179 +       dot_de = (struct ext4_dir_entry_2 *)bh->b_data;
 180 +       dotdot_de = ext4_next_entry(dot_de, blocksize);
 181
 182         /* The 0th block becomes the root, move the dirents out */
 183 -       fde = &root->dotdot;
 184 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 185 -               ext4_rec_len_from_disk(fde->rec_len, blocksize));
 186 -       if ((char *) de >= (((char *) root) + blocksize)) {
 187 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 188 +               ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
 189 +       if ((char *)de >= (((char *)dot_de) + blocksize)) {
 190                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
 191                 brelse(bh);
 192                 return -EFSCORRUPTED;
 193         }
 194 -       len = ((char *) root) + (blocksize - csum_size) - (char *) de;
 195 +       len = ((char *)dot_de) + (blocksize - csum_size) - (char *)de;
 196
 197         /* Allocate new block for the 0th block's dirents */
 198         bh2 = ext4_append(handle, dir, &block);
 199 @@ -2241,24 +2241,26 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 200                 ext4_initialize_dirent_tail(bh2, blocksize);
 201
 202         /* Initialize the root; the dot dirents already exist */
 203 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 204 -       de->rec_len = ext4_rec_len_to_disk(
 205 -                       blocksize - ext4_dir_rec_len(2, NULL), blocksize);
 206 -       memset (&root->info, 0, sizeof(root->info));
 207 -       root->info.info_length = sizeof(root->info);
 208 +       dotdot_de->rec_len =
 209 +               ext4_rec_len_to_disk(blocksize - le16_to_cpu(dot_de->rec_len),
 210 +                                    blocksize);
 211 +
 212 +       /* initialize hashing info */
 213 +       dx_info = dx_get_dx_info(dot_de);
 214 +       memset(dx_info, 0, sizeof(*dx_info));
 215 +       dx_info->info_length = sizeof(*dx_info);
 216         if (ext4_hash_in_dirent(dir))
 217 -               root->info.hash_version = DX_HASH_SIPHASH;
 218 +               dx_info->hash_version = DX_HASH_SIPHASH;
 219         else
 220 -               root->info.hash_version =
 221 +               dx_info->hash_version =
 222                                 EXT4_SB(dir->i_sb)->s_def_hash_version;
 223 -
 224 -       entries = root->entries;
 225 +       entries = (void *)dx_info + sizeof(*dx_info);
 226         dx_set_block(entries, 1);
 227         dx_set_count(entries, 1);
 228 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
 229 +       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 230
 231         /* Initialize as for dx_probe */
 232 -       fname->hinfo.hash_version = root->info.hash_version;
 233 +       fname->hinfo.hash_version = dx_info->hash_version;
 234         if (fname->hinfo.hash_version <= DX_HASH_TEA)
 235                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 236         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 237 @@ -2626,7 +2628,7 @@ again:
 238                         if (restart || err)
 239                                 goto journal_error;
 240                 } else {
 241 -                       struct dx_root *dxroot;
 242 +                       struct dx_root_info *info;
 243                         memcpy((char *) entries2, (char *) entries,
 244                                icount * sizeof(struct dx_entry));
 245                         dx_set_limit(entries2, dx_node_limit(dir));
 246 @@ -2634,8 +2636,9 @@ again:
 247                         /* Set up root */
 248                         dx_set_count(entries, 1);
 249                         dx_set_block(entries + 0, newblock);
 250 -                       dxroot = (struct dx_root *)frames[0].bh->b_data;
 251 -                       dxroot->info.indirect_levels += 1;
 252 +                       info = dx_get_dx_info((struct ext4_dir_entry_2 *)
 253 +                                             frames[0].bh->b_data);
 254 +                       info->indirect_levels = 1;
 255                         dxtrace(printk(KERN_DEBUG
 256                                        "Creating %d level index...\n",
 257                                        dxroot->info.indirect_levels));
 258 --
 259 2.31.1
 260