ldiskfs/kernel_patches/patches/ext4-kill-dx_root.patch

   1 removes static definition of dx_root struct. so that "." and ".." dirent can
   2 have extra data. This patch does not change any functionality but is required for
   3 ext4_data_in_dirent patch.
   4
   5 Index: b/fs/ext4/namei.c
   6 ===================================================================
   7 --- a/fs/ext4/namei.c
   8 +++ b/fs/ext4/namei.c
   9 @@ -121,22 +121,13 @@ struct dx_entry
  10   * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
  11   */
  12
  13 -struct dx_root
  14 +struct dx_root_info
  15  {
  16 -       struct fake_dirent dot;
  17 -       char dot_name[4];
  18 -       struct fake_dirent dotdot;
  19 -       char dotdot_name[4];
  20 -       struct dx_root_info
  21 -       {
  22 -               __le32 reserved_zero;
  23 -               u8 hash_version;
  24 -               u8 info_length; /* 8 */
  25 -               u8 indirect_levels;
  26 -               u8 unused_flags;
  27 -       }
  28 -       info;
  29 -       struct dx_entry entries[0];
  30 +       __le32 reserved_zero;
  31 +       u8 hash_version;
  32 +       u8 info_length; /* 8 */
  33 +       u8 indirect_levels;
  34 +       u8 unused_flags;
  35  };
  36
  37  struct dx_node
  38 @@ -225,6 +216,16 @@ ext4_next_entry(struct ext4_dir_entry_2
  39   * Future: use high four bits of block for coalesce-on-delete flags
  40   * Mask them off for now.
  41   */
  42 +struct dx_root_info * dx_get_dx_info(struct ext4_dir_entry_2 *de)
  43 +{
  44 +       /* get dotdot first */
  45 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
  46 +
  47 +       /* dx root info is after dotdot entry */
  48 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
  49 +
  50 +       return (struct dx_root_info *) de;
  51 +}
  52
  53  static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
  54  {
  55 @@ -378,7 +379,7 @@ dx_probe(struct dentry *dentry, struct i
  56  {
  57         unsigned count, indirect;
  58         struct dx_entry *at, *entries, *p, *q, *m;
  59 -       struct dx_root *root;
  60 +       struct dx_root_info * info;
  61         struct buffer_head *bh;
  62         struct dx_frame *frame = frame_in;
  63         u32 hash;
  64 @@ -388,46 +389,46 @@ dx_probe(struct dentry *dentry, struct i
  65                 dir = dentry->d_parent->d_inode;
  66         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
  67                 goto fail;
  68 -       root = (struct dx_root *) bh->b_data;
  69 -       if (root->info.hash_version != DX_HASH_TEA &&
  70 -           root->info.hash_version != DX_HASH_HALF_MD4 &&
  71 -           root->info.hash_version != DX_HASH_LEGACY) {
  72 +
  73 +       info = dx_get_dx_info((struct ext4_dir_entry_2*)bh->b_data);
  74 +       if (info->hash_version != DX_HASH_TEA &&
  75 +           info->hash_version != DX_HASH_HALF_MD4 &&
  76 +           info->hash_version != DX_HASH_LEGACY) {
  77                 ext4_warning(dir->i_sb, __func__,
  78                              "Unrecognised inode hash code %d for directory "
  79 -                            "#%lu", root->info.hash_version, dir->i_ino);
  80 +                            "#%lu", info->hash_version, dir->i_ino);
  81                 brelse(bh);
  82                 *err = ERR_BAD_DX_DIR;
  83                 goto fail;
  84         }
  85 -       hinfo->hash_version = root->info.hash_version;
  86 +       hinfo->hash_version = info->hash_version;
  87         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
  88         if (dentry)
  89                 ext4fs_dirhash(dentry->d_name.name, dentry->d_name.len, hinfo);
  90         hash = hinfo->hash;
  91
  92 -       if (root->info.unused_flags & 1) {
  93 +       if (info->unused_flags & 1) {
  94                 ext4_warning(dir->i_sb, __func__,
  95                              "Unimplemented inode hash flags: %#06x",
  96 -                            root->info.unused_flags);
  97 +                            info->unused_flags);
  98                 brelse(bh);
  99                 *err = ERR_BAD_DX_DIR;
 100                 goto fail;
 101         }
 102
 103 -       if ((indirect = root->info.indirect_levels) > 1) {
 104 +       if ((indirect = info->indirect_levels) > 1) {
 105                 ext4_warning(dir->i_sb, __func__,
 106                              "Unimplemented inode hash depth: %#06x",
 107 -                            root->info.indirect_levels);
 108 +                            info->indirect_levels);
 109                 brelse(bh);
 110                 *err = ERR_BAD_DX_DIR;
 111                 goto fail;
 112         }
 113
 114 -       entries = (struct dx_entry *) (((char *)&root->info) +
 115 -                                      root->info.info_length);
 116 +       entries = (struct dx_entry *) (((char *)info) + info->info_length);
 117
 118         if (dx_get_limit(entries) != dx_root_limit(dir,
 119 -                                                  root->info.info_length)) {
 120 +                                                  info->info_length)) {
 121                 ext4_warning(dir->i_sb, __func__,
 122                              "dx entry: limit != root limit");
 123                 brelse(bh);
 124 @@ -509,10 +510,12 @@ fail:
 125
 126  static void dx_release (struct dx_frame *frames)
 127  {
 128 +       struct dx_root_info *info;
 129         if (frames[0].bh == NULL)
 130                 return;
 131
 132 -       if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 133 +       info = dx_get_dx_info((struct ext4_dir_entry_2*)frames[0].bh->b_data);
 134 +       if (info->indirect_levels)
 135                 brelse(frames[1].bh);
 136         brelse(frames[0].bh);
 137  }
 138 @@ -1430,17 +1433,16 @@ static int make_indexed_dir(handle_t *ha
 139         const char      *name = dentry->d_name.name;
 140         int             namelen = dentry->d_name.len;
 141         struct buffer_head *bh2;
 142 -       struct dx_root  *root;
 143         struct dx_frame frames[2], *frame;
 144         struct dx_entry *entries;
 145 -       struct ext4_dir_entry_2 *de, *de2;
 146 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 147         char            *data1, *top;
 148         unsigned        len;
 149         int             retval;
 150         unsigned        blocksize;
 151         struct dx_hash_info hinfo;
 152         ext4_lblk_t  block;
 153 -       struct fake_dirent *fde;
 154 +       struct dx_root_info *dx_info;
 155
 156         blocksize =  dir->i_sb->s_blocksize;
 157         dxtrace(printk("Creating index\n"));
 158 @@ -1450,7 +1452,6 @@ static int make_indexed_dir(handle_t *ha
 159                 brelse(bh);
 160                 return retval;
 161         }
 162 -       root = (struct dx_root *) bh->b_data;
 163
 164         bh2 = ext4_append (handle, dir, &block, &retval);
 165         if (!(bh2)) {
 166 @@ -1460,11 +1461,13 @@ static int make_indexed_dir(handle_t *ha
 167         EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
 168         data1 = bh2->b_data;
 169
 170 +       dot_de = (struct ext4_dir_entry_2 *) bh->b_data;
 171 +       dotdot_de = ext4_next_entry(dot_de);
 172 +
 173         /* The 0th block becomes the root, move the dirents out */
 174 -       fde = &root->dotdot;
 175 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 176 -               ext4_rec_len_from_disk(fde->rec_len));
 177 -       len = ((char *) root) + blocksize - (char *) de;
 178 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 179 +               ext4_rec_len_from_disk(dotdot_de->rec_len));
 180 +       len = ((char *) dot_de) + blocksize - (char *) de;
 181         memcpy (data1, de, len);
 182         de = (struct ext4_dir_entry_2 *) data1;
 183         top = data1 + len;
 184 @@ -1472,18 +1475,24 @@ static int make_indexed_dir(handle_t *ha
 185                 de = de2;
 186         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
 187         /* Initialize the root; the dot dirents already exist */
 188 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 189 -       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2));
 190 -       memset (&root->info, 0, sizeof(root->info));
 191 -       root->info.info_length = sizeof(root->info);
 192 -       root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 193 -       entries = root->entries;
 194 -       dx_set_block (entries, 1);
 195 -       dx_set_count (entries, 1);
 196 -       dx_set_limit (entries, dx_root_limit(dir, sizeof(root->info)));
 197 +       dotdot_de->rec_len = ext4_rec_len_to_disk(blocksize -
 198 +                       le16_to_cpu(dot_de->rec_len));
 199 +
 200 +       /* initialize hashing info */
 201 +       dx_info = dx_get_dx_info(dot_de);
 202 +       memset (dx_info, 0, sizeof(*dx_info));
 203 +       dx_info->info_length = sizeof(*dx_info);
 204 +       dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 205 +
 206 +       entries = (void *)dx_info + sizeof(*dx_info);
 207 +
 208 +       dx_set_block(entries, 1);
 209 +       dx_set_count(entries, 1);
 210 +       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 211
 212         /* Initialize as for dx_probe */
 213 -       hinfo.hash_version = root->info.hash_version;
 214 +       hinfo.hash_version = dx_info->hash_version;
 215 +
 216         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 217         ext4fs_dirhash(name, namelen, &hinfo);
 218         frame = frames;
 219 @@ -1724,6 +1733,7 @@ static int ext4_dx_add_entry(handle_t *h
 220                                 goto journal_error;
 221                         brelse (bh2);
 222                 } else {
 223 +                       struct dx_root_info * info;
 224                         dxtrace(printk("Creating second level index...\n"));
 225                         memcpy((char *) entries2, (char *) entries,
 226                                icount * sizeof(struct dx_entry));
 227 @@ -1732,7 +1742,9 @@ static int ext4_dx_add_entry(handle_t *h
 228                         /* Set up root */
 229                         dx_set_count(entries, 1);
 230                         dx_set_block(entries + 0, newblock);
 231 -                       ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
 232 +                       info = dx_get_dx_info((struct ext4_dir_entry_2*)
 233 +                                       frames[0].bh->b_data);
 234 +                       info->indirect_levels = 1;
 235
 236                         /* Add new access path frame */
 237                         frame = frames + 1;