ldiskfs/kernel_patches/patches/ubuntu18/ext4-kill-dx-root.patch

   1 Index: linux-4.15.0/fs/ext4/namei.c
   2 ===================================================================
   3 --- linux-4.15.0.orig/fs/ext4/namei.c
   4 +++ linux-4.15.0/fs/ext4/namei.c
   5 @@ -196,22 +196,13 @@ struct dx_entry
   6   * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
   7   */
   8
   9 -struct dx_root
  10 +struct dx_root_info
  11  {
  12 -       struct fake_dirent dot;
  13 -       char dot_name[4];
  14 -       struct fake_dirent dotdot;
  15 -       char dotdot_name[4];
  16 -       struct dx_root_info
  17 -       {
  18 -               __le32 reserved_zero;
  19 -               u8 hash_version;
  20 -               u8 info_length; /* 8 */
  21 -               u8 indirect_levels;
  22 -               u8 unused_flags;
  23 -       }
  24 -       info;
  25 -       struct dx_entry entries[0];
  26 +       __le32 reserved_zero;
  27 +       u8 hash_version;
  28 +       u8 info_length; /* 8 */
  29 +       u8 indirect_levels;
  30 +       u8 unused_flags;
  31  };
  32
  33  struct dx_node
  34 @@ -512,6 +503,16 @@ ext4_next_entry(struct ext4_dir_entry_2
  35   * Future: use high four bits of block for coalesce-on-delete flags
  36   * Mask them off for now.
  37   */
  38 +struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de)
  39 +{
  40 +       /* get dotdot first */
  41 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
  42 +
  43 +       /* dx root info is after dotdot entry */
  44 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
  45 +
  46 +       return (struct dx_root_info *)de;
  47 +}
  48
  49  static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
  50  {
  51 @@ -736,7 +737,7 @@ dx_probe(struct ext4_filename *fname, st
  52  {
  53         unsigned count, indirect;
  54         struct dx_entry *at, *entries, *p, *q, *m;
  55 -       struct dx_root *root;
  56 +       struct dx_root_info *info;
  57         struct dx_frame *frame = frame_in;
  58         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
  59         u32 hash;
  60 @@ -745,18 +746,17 @@ dx_probe(struct ext4_filename *fname, st
  61         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
  62         if (IS_ERR(frame->bh))
  63                 return (struct dx_frame *) frame->bh;
  64 -
  65 -       root = (struct dx_root *) frame->bh->b_data;
  66 -       if (root->info.hash_version != DX_HASH_TEA &&
  67 -           root->info.hash_version != DX_HASH_HALF_MD4 &&
  68 -           root->info.hash_version != DX_HASH_LEGACY) {
  69 -               ext4_warning_inode(dir, "Unrecognised inode hash code %u for directory "
  70 -                                  "%lu", root->info.hash_version, dir->i_ino);
  71 +       info = dx_get_dx_info((struct ext4_dir_entry_2 *)frame->bh->b_data);
  72 +        if (info->hash_version != DX_HASH_TEA &&
  73 +            info->hash_version != DX_HASH_HALF_MD4 &&
  74 +            info->hash_version != DX_HASH_LEGACY) {
  75 +               ldiskfs_warning(dir->i_sb, "Unrecognised inode hash code %d for directory "
  76 +                             "#%lu", info->hash_version, dir->i_ino);
  77                 goto fail;
  78         }
  79         if (fname)
  80                 hinfo = &fname->hinfo;
  81 -       hinfo->hash_version = root->info.hash_version;
  82 +       hinfo->hash_version = info->hash_version;
  83         if (hinfo->hash_version <= DX_HASH_TEA)
  84                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
  85         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
  86 @@ -764,13 +764,13 @@ dx_probe(struct ext4_filename *fname, st
  87                 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
  88         hash = hinfo->hash;
  89
  90 -       if (root->info.unused_flags & 1) {
  91 +       if (info->unused_flags & 1) {
  92                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
  93 -                                  root->info.unused_flags);
  94 +                                  info->unused_flags);
  95                 goto fail;
  96         }
  97
  98 -       indirect = root->info.indirect_levels;
  99 +       indirect = info->indirect_levels;
 100         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
 101                 ext4_warning(dir->i_sb,
 102                              "Directory (ino: %lu) htree depth %#06x exceed"
 103 @@ -783,14 +783,13 @@ dx_probe(struct ext4_filename *fname, st
 104                 goto fail;
 105         }
 106
 107 -       entries = (struct dx_entry *)(((char *)&root->info) +
 108 -                                     root->info.info_length);
 109 +       entries = (struct dx_entry *)(((char *)info) + info->info_length);
 110
 111         if (dx_get_limit(entries) != dx_root_limit(dir,
 112 -                                                  root->info.info_length)) {
 113 +                                                  info->info_length)) {
 114                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 115                                    dx_get_limit(entries),
 116 -                                  dx_root_limit(dir, root->info.info_length));
 117 +                                  dx_root_limit(dir, info->info_length));
 118                 goto fail;
 119         }
 120
 121 @@ -874,7 +873,7 @@ static void dx_release(struct dx_frame *
 122         if (frames[0].bh == NULL)
 123                 return;
 124
 125 -       info = &((struct dx_root *)frames[0].bh->b_data)->info;
 126 +       info = dx_get_dx_info((struct ext4_dir_entry_2 *)frames[0].bh->b_data);
 127         for (i = 0; i <= info->indirect_levels; i++) {
 128                 if (frames[i].bh == NULL)
 129                         break;
 130 @@ -1930,17 +1929,16 @@ static int make_indexed_dir(handle_t *ha
 131                             struct inode *inode, struct buffer_head *bh)
 132  {
 133         struct buffer_head *bh2;
 134 -       struct dx_root  *root;
 135         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
 136         struct dx_entry *entries;
 137 -       struct ext4_dir_entry_2 *de, *de2;
 138 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 139         struct ext4_dir_entry_tail *t;
 140         char            *data1, *top;
 141         unsigned        len;
 142         int             retval;
 143         unsigned        blocksize;
 144         ext4_lblk_t  block;
 145 -       struct fake_dirent *fde;
 146 +       struct dx_root_info *dx_info;
 147         int csum_size = 0;
 148
 149         if (ext4_has_metadata_csum(inode->i_sb))
 150 @@ -1955,18 +1953,19 @@ static int make_indexed_dir(handle_t *ha
 151                 brelse(bh);
 152                 return retval;
 153         }
 154 -       root = (struct dx_root *) bh->b_data;
 155 +
 156 +       dot_de = (struct ext4_dir_entry_2 *)bh->b_data;
 157 +       dotdot_de = ext4_next_entry(dot_de, blocksize);
 158
 159         /* The 0th block becomes the root, move the dirents out */
 160 -       fde = &root->dotdot;
 161 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 162 -               ext4_rec_len_from_disk(fde->rec_len, blocksize));
 163 -       if ((char *) de >= (((char *) root) + blocksize)) {
 164 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 165 +               ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
 166 +       if ((char *)de >= (((char *)dot_de) + blocksize)) {
 167                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
 168                 brelse(bh);
 169                 return -EFSCORRUPTED;
 170         }
 171 -       len = ((char *) root) + (blocksize - csum_size) - (char *) de;
 172 +       len = ((char *)dot_de) + (blocksize - csum_size) - (char *)de;
 173
 174         /* Allocate new block for the 0th block's dirents */
 175         bh2 = ext4_append(handle, dir, &block);
 176 @@ -1992,19 +1991,24 @@ static int make_indexed_dir(handle_t *ha
 177         }
 178
 179         /* Initialize the root; the dot dirents already exist */
 180 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 181 -       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
 182 -                                          blocksize);
 183 -       memset (&root->info, 0, sizeof(root->info));
 184 -       root->info.info_length = sizeof(root->info);
 185 -       root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 186 -       entries = root->entries;
 187 +       dotdot_de->rec_len =
 188 +               ext4_rec_len_to_disk(blocksize - le16_to_cpu(dot_de->rec_len),
 189 +                                    blocksize);
 190 +
 191 +       /* initialize hashing info */
 192 +       dx_info = dx_get_dx_info(dot_de);
 193 +       memset(dx_info, 0, sizeof(*dx_info));
 194 +       dx_info->info_length = sizeof(*dx_info);
 195 +       dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 196 +
 197 +       entries = (void *)dx_info + sizeof(*dx_info);
 198 +
 199         dx_set_block(entries, 1);
 200         dx_set_count(entries, 1);
 201 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
 202 +       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 203
 204         /* Initialize as for dx_probe */
 205 -       fname->hinfo.hash_version = root->info.hash_version;
 206 +       fname->hinfo.hash_version = dx_info->hash_version;
 207         if (fname->hinfo.hash_version <= DX_HASH_TEA)
 208                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 209         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 210 @@ -2346,7 +2350,7 @@ again:
 211                                 goto journal_error;
 212                         }
 213                 } else {
 214 -                       struct dx_root *dxroot;
 215 +                       struct dx_root_info *info;
 216                         memcpy((char *) entries2, (char *) entries,
 217                                icount * sizeof(struct dx_entry));
 218                         dx_set_limit(entries2, dx_node_limit(dir));
 219 @@ -2354,8 +2358,9 @@ again:
 220                         /* Set up root */
 221                         dx_set_count(entries, 1);
 222                         dx_set_block(entries + 0, newblock);
 223 -                       dxroot = (struct dx_root *)frames[0].bh->b_data;
 224 -                       dxroot->info.indirect_levels += 1;
 225 +                       info = dx_get_dx_info((struct ext4_dir_entry_2 *)
 226 +                                             frames[0].bh->b_data);
 227 +                       info->indirect_levels = 1;
 228                         dxtrace(printk(KERN_DEBUG
 229                                        "Creating %d level index...\n",
 230                                        info->indirect_levels));