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 @@ -388,18 +389,19 @@ 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         if (hinfo->hash_version <= DX_HASH_TEA)
  88                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
  89         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
  90 @@ -398,29 +399,28 @@ dx_probe(struct dentry *dentry, struct i
  91                 ext4fs_dirhash(dentry->d_name.name, dentry->d_name.len, hinfo);
  92         hash = hinfo->hash;
  93
  94 -       if (root->info.unused_flags & 1) {
  95 +       if (info->unused_flags & 1) {
  96                 ext4_warning(dir->i_sb, __func__,
  97                              "Unimplemented inode hash flags: %#06x",
  98 -                            root->info.unused_flags);
  99 +                            info->unused_flags);
 100                 brelse(bh);
 101                 *err = ERR_BAD_DX_DIR;
 102                 goto fail;
 103         }
 104
 105 -       if ((indirect = root->info.indirect_levels) > 1) {
 106 +       if ((indirect = info->indirect_levels) > 1) {
 107                 ext4_warning(dir->i_sb, __func__,
 108                              "Unimplemented inode hash depth: %#06x",
 109 -                            root->info.indirect_levels);
 110 +                            info->indirect_levels);
 111                 brelse(bh);
 112                 *err = ERR_BAD_DX_DIR;
 113                 goto fail;
 114         }
 115
 116 -       entries = (struct dx_entry *) (((char *)&root->info) +
 117 -                                      root->info.info_length);
 118 +       entries = (struct dx_entry *) (((char *)info) + info->info_length);
 119
 120         if (dx_get_limit(entries) != dx_root_limit(dir,
 121 -                                                  root->info.info_length)) {
 122 +                                                  info->info_length)) {
 123                 ext4_warning(dir->i_sb, __func__,
 124                              "dx entry: limit != root limit");
 125                 brelse(bh);
 126 @@ -509,10 +510,12 @@ fail:
 127
 128  static void dx_release (struct dx_frame *frames)
 129  {
 130 +       struct dx_root_info *info;
 131         if (frames[0].bh == NULL)
 132                 return;
 133
 134 -       if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 135 +       info = dx_get_dx_info((struct ext4_dir_entry_2*)frames[0].bh->b_data);
 136 +       if (info->indirect_levels)
 137                 brelse(frames[1].bh);
 138         brelse(frames[0].bh);
 139  }
 140 @@ -1430,17 +1433,16 @@ static int make_indexed_dir(handle_t *ha
 141         const char      *name = dentry->d_name.name;
 142         int             namelen = dentry->d_name.len;
 143         struct buffer_head *bh2;
 144 -       struct dx_root  *root;
 145         struct dx_frame frames[2], *frame;
 146         struct dx_entry *entries;
 147 -       struct ext4_dir_entry_2 *de, *de2;
 148 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 149         char            *data1, *top;
 150         unsigned        len;
 151         int             retval;
 152         unsigned        blocksize;
 153         struct dx_hash_info hinfo;
 154         ext4_lblk_t  block;
 155 -       struct fake_dirent *fde;
 156 +       struct dx_root_info *dx_info;
 157
 158         blocksize =  dir->i_sb->s_blocksize;
 159         dxtrace(printk("Creating index\n"));
 160 @@ -1450,7 +1452,6 @@ static int make_indexed_dir(handle_t *ha
 161                 brelse(bh);
 162                 return retval;
 163         }
 164 -       root = (struct dx_root *) bh->b_data;
 165
 166         bh2 = ext4_append (handle, dir, &block, &retval);
 167         if (!(bh2)) {
 168 @@ -1460,18 +1461,20 @@ static int make_indexed_dir(handle_t *ha
 169         }
 170         root = (struct dx_root *) bh->b_data;
 171
 172 +       dot_de = (struct ext4_dir_entry_2 *) bh->b_data;
 173 +       dotdot_de = ext4_next_entry(dot_de, blocksize);
 174 +
 175         /* The 0th block becomes the root, move the dirents out */
 176 -       fde = &root->dotdot;
 177 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 178 -               ext4_rec_len_from_disk(fde->rec_len, blocksize));
 179 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 180 +               ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
 181 -       if ((char *) de >= (((char *) root) + blocksize)) {
 182 +       if ((char *) de >= (((char *) dot_de) + blocksize)) {
 183                 ext4_error(dir->i_sb, __func__,
 184                            "invalid rec_len for '..' in inode %lu",
 185                            dir->i_ino);
 186                 brelse(bh);
 187                 return -EIO;
 188         }
 189 -       len = ((char *) root) + blocksize - (char *) de;
 190 +       len = ((char *) dot_de) + blocksize - (char *) de;
 191
 192         /* Allocate new block for the 0th block's dirents */
 193         bh2 = ext4_append(handle, dir, &block, &retval);
 194 @@ -1472,19 +1475,23 @@ static int make_indexed_dir(handle_t *ha
 195         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
 196                                            blocksize);
 197         /* Initialize the root; the dot dirents already exist */
 198 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 199 -       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
 200 -                                          blocksize);
 201 -       memset (&root->info, 0, sizeof(root->info));
 202 -       root->info.info_length = sizeof(root->info);
 203 -       root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 204 -       entries = root->entries;
 205 -       dx_set_block(entries, 1);
 206 -       dx_set_count(entries, 1);
 207 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
 208 +       dotdot_de->rec_len = ext4_rec_len_to_disk(blocksize -
 209 +                       le16_to_cpu(dot_de->rec_len), blocksize);
 210 +
 211 +       /* initialize hashing info */
 212 +       dx_info = dx_get_dx_info(dot_de);
 213 +       memset (dx_info, 0, sizeof(*dx_info));
 214 +       dx_info->info_length = sizeof(*dx_info);
 215 +       dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 216 +
 217 +       entries = (void *)dx_info + sizeof(*dx_info);
 218 +
 219 +       dx_set_block(entries, 1);
 220 +       dx_set_count(entries, 1);
 221 +       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 222
 223         /* Initialize as for dx_probe */
 224 -       hinfo.hash_version = root->info.hash_version;
 225 +       hinfo.hash_version = dx_info->hash_version;
 226         if (hinfo.hash_version <= DX_HASH_TEA)
 227                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 228         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 229 @@ -1724,6 +1733,7 @@ static int ext4_dx_add_entry(handle_t *h
 230                                 goto journal_error;
 231                         brelse (bh2);
 232                 } else {
 233 +                       struct dx_root_info * info;
 234                         dxtrace(printk(KERN_DEBUG
 235                                        "Creating second level index...\n"));
 236                         memcpy((char *) entries2, (char *) entries,
 237 @@ -1732,7 +1742,9 @@ static int ext4_dx_add_entry(handle_t *h
 238                         /* Set up root */
 239                         dx_set_count(entries, 1);
 240                         dx_set_block(entries + 0, newblock);
 241 -                       ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
 242 +                       info = dx_get_dx_info((struct ext4_dir_entry_2*)
 243 +                                       frames[0].bh->b_data);
 244 +                       info->indirect_levels = 1;
 245
 246                         /* Add new access path frame */
 247                         frame = frames + 1;