ldiskfs/kernel_patches/patches/ext4-kill-dx_root-rhel6.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: linux-2.6.32.i386/fs/ext4/namei.c
   6 ===================================================================
   7 --- linux-2.6.32.i386.orig/fs/ext4/namei.c      2010-04-16 05:35:06.000000000 +0530
   8 +++ linux-2.6.32.i386/fs/ext4/namei.c   2010-04-16 05:47:41.000000000 +0530
   9 @@ -115,22 +115,13 @@
  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 @@ -244,6 +235,16 @@
  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 @@ -398,7 +399,7 @@
  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 @@ -406,17 +407,18 @@
  65         frame->bh = NULL;
  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, "Unrecognised inode hash code %d for directory "
  78 -                             "#%lu", root->info.hash_version, dir->i_ino);
  79 +                             "#%lu", info->hash_version, dir->i_ino);
  80                 brelse(bh);
  81                 *err = ERR_BAD_DX_DIR;
  82                 goto fail;
  83         }
  84 -       hinfo->hash_version = root->info.hash_version;
  85 +       hinfo->hash_version = info->hash_version;
  86         if (hinfo->hash_version <= DX_HASH_TEA)
  87                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
  88         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
  89 @@ -425,27 +427,26 @@
  90                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
  91         hash = hinfo->hash;
  92
  93 -       if (root->info.unused_flags & 1) {
  94 +       if (info->unused_flags & 1) {
  95                 ext4_warning(dir->i_sb, "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, "Unimplemented inode hash depth: %#06x",
 106 -                            root->info.indirect_levels);
 107 +                            info->indirect_levels);
 108                 brelse(bh);
 109                 *err = ERR_BAD_DX_DIR;
 110                 goto fail;
 111         }
 112
 113 -       entries = (struct dx_entry *) (((char *)&root->info) +
 114 -                                      root->info.info_length);
 115 +       entries = (struct dx_entry *) (((char *)info) + info->info_length);
 116
 117         if (dx_get_limit(entries) != dx_root_limit(dir,
 118 -                                                  root->info.info_length)) {
 119 +                                                  info->info_length)) {
 120                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 121                 brelse(bh);
 122                 *err = ERR_BAD_DX_DIR;
 123 @@ -525,10 +526,12 @@ fail:
 124
 125  static void dx_release (struct dx_frame *frames)
 126  {
 127 +       struct dx_root_info *info;
 128         if (frames[0].bh == NULL)
 129                 return;
 130
 131 -       if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 132 +       info = dx_get_dx_info((struct ext4_dir_entry_2*)frames[0].bh->b_data);
 133 +       if (info->indirect_levels)
 134                 brelse(frames[1].bh);
 135         brelse(frames[0].bh);
 136  }
 137 @@ -1447,17 +1450,16 @@
 138         const char      *name = dentry->d_name.name;
 139         int             namelen = dentry->d_name.len;
 140         struct buffer_head *bh2;
 141 -       struct dx_root  *root;
 142         struct dx_frame frames[2], *frame;
 143         struct dx_entry *entries;
 144 -       struct ext4_dir_entry_2 *de, *de2;
 145 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 146         char            *data1, *top;
 147         unsigned        len;
 148         int             retval;
 149         unsigned        blocksize;
 150         struct dx_hash_info hinfo;
 151         ext4_lblk_t  block;
 152 -       struct fake_dirent *fde;
 153 +       struct dx_root_info *dx_info;
 154
 155         blocksize =  dir->i_sb->s_blocksize;
 156         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
 157 @@ -1467,20 +1469,21 @@
 158                 brelse(bh);
 159                 return retval;
 160         }
 161 -       root = (struct dx_root *) bh->b_data;
 162 +
 163 +       dot_de = (struct ext4_dir_entry_2 *) bh->b_data;
 164 +       dotdot_de = ext4_next_entry(dot_de, blocksize);
 165
 166         /* The 0th block becomes the root, move the dirents out */
 167 -       fde = &root->dotdot;
 168 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 169 -               ext4_rec_len_from_disk(fde->rec_len, blocksize));
 170 -       if ((char *) de >= (((char *) root) + blocksize)) {
 171 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 172 +               ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
 173 +       if ((char *) de >= (((char *) dot_de) + blocksize)) {
 174                 ext4_error(dir->i_sb,
 175                            "invalid rec_len for '..' in inode %lu",
 176                            dir->i_ino);
 177                 brelse(bh);
 178                 return -EIO;
 179         }
 180 -       len = ((char *) root) + blocksize - (char *) de;
 181 +       len = ((char *) dot_de) + blocksize - (char *) de;
 182
 183         /* Allocate new block for the 0th block's dirents */
 184         bh2 = ext4_append(handle, dir, &block, &retval);
 185 @@ -1499,19 +1502,23 @@
 186         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
 187                                            blocksize);
 188         /* Initialize the root; the dot dirents already exist */
 189 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 190 -       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
 191 -                                          blocksize);
 192 -       memset (&root->info, 0, sizeof(root->info));
 193 -       root->info.info_length = sizeof(root->info);
 194 -       root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 195 -       entries = root->entries;
 196 +       dotdot_de->rec_len = ext4_rec_len_to_disk(blocksize -
 197 +                       le16_to_cpu(dot_de->rec_len), blocksize);
 198 +
 199 +       /* initialize hashing info */
 200 +       dx_info = dx_get_dx_info(dot_de);
 201 +       memset (dx_info, 0, sizeof(*dx_info));
 202 +       dx_info->info_length = sizeof(*dx_info);
 203 +       dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 204 +
 205 +       entries = (void *)dx_info + sizeof(*dx_info);
 206 +
 207         dx_set_block(entries, 1);
 208         dx_set_count(entries, 1);
 209 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
 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         if (hinfo.hash_version <= DX_HASH_TEA)
 216                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 217         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 218 @@ -1759,6 +1766,7 @@
 219                                 goto journal_error;
 220                         brelse (bh2);
 221                 } else {
 222 +                       struct dx_root_info * info;
 223                         dxtrace(printk(KERN_DEBUG
 224                                        "Creating second level index...\n"));
 225                         memcpy((char *) entries2, (char *) entries,
 226 @@ -1768,7 +1776,9 @@
 227                         /* Set up root */
 228                         dx_set_count(entries, 1);
 229                         dx_set_block(entries + 0, newblock);
 230 -                       ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
 231 +                       info = dx_get_dx_info((struct ext4_dir_entry_2*)
 232 +                                       frames[0].bh->b_data);
 233 +                       info->indirect_levels = 1;
 234
 235                         /* Add new access path frame */
 236                         frame = frames + 1;