ldiskfs/kernel_patches/patches/sles11sp2/ext4-kill-dx_root.patch

   1 diff -r -u linux-stage.orig/fs/ext4/namei.c linux-stage/fs/ext4/namei.c
   2 --- linux-stage.orig/fs/ext4/namei.c    2012-12-31 15:03:28.000000000 -0500
   3 +++ linux-stage/fs/ext4/namei.c 2012-12-31 15:06:16.000000000 -0500
   4 @@ -115,22 +115,13 @@
   5   * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
   6   */
   7
   8 -struct dx_root
   9 +struct dx_root_info
  10  {
  11 -       struct fake_dirent dot;
  12 -       char dot_name[4];
  13 -       struct fake_dirent dotdot;
  14 -       char dotdot_name[4];
  15 -       struct dx_root_info
  16 -       {
  17 -               __le32 reserved_zero;
  18 -               u8 hash_version;
  19 -               u8 info_length; /* 8 */
  20 -               u8 indirect_levels;
  21 -               u8 unused_flags;
  22 -       }
  23 -       info;
  24 -       struct dx_entry entries[0];
  25 +       __le32 reserved_zero;
  26 +       u8 hash_version;
  27 +       u8 info_length; /* 8 */
  28 +       u8 indirect_levels;
  29 +       u8 unused_flags;
  30  };
  31
  32  struct dx_node
  33 @@ -220,6 +211,16 @@
  34   * Future: use high four bits of block for coalesce-on-delete flags
  35   * Mask them off for now.
  36   */
  37 +struct dx_root_info * dx_get_dx_info(struct ext4_dir_entry_2 *de)
  38 +{
  39 +       /* get dotdot first */
  40 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
  41 +
  42 +       /* dx root info is after dotdot entry */
  43 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
  44 +
  45 +       return (struct dx_root_info *) de;
  46 +}
  47
  48  static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
  49  {
  50 @@ -374,7 +375,7 @@
  51  {
  52         unsigned count, indirect;
  53         struct dx_entry *at, *entries, *p, *q, *m;
  54 -       struct dx_root *root;
  55 +       struct dx_root_info * info;
  56         struct buffer_head *bh;
  57         struct dx_frame *frame = frame_in;
  58         u32 hash;
  59 @@ -382,17 +383,18 @@
  60         frame->bh = NULL;
  61         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
  62                 goto fail;
  63 -       root = (struct dx_root *) bh->b_data;
  64 -       if (root->info.hash_version != DX_HASH_TEA &&
  65 -           root->info.hash_version != DX_HASH_HALF_MD4 &&
  66 -           root->info.hash_version != DX_HASH_LEGACY) {
  67 +
  68 +       info = dx_get_dx_info((struct ext4_dir_entry_2*)bh->b_data);
  69 +       if (info->hash_version != DX_HASH_TEA &&
  70 +           info->hash_version != DX_HASH_HALF_MD4 &&
  71 +           info->hash_version != DX_HASH_LEGACY) {
  72                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d for directory "
  73 -                             "#%lu", root->info.hash_version, dir->i_ino);
  74 +                             "#%lu", info->hash_version, dir->i_ino);
  75                 brelse(bh);
  76                 *err = ERR_BAD_DX_DIR;
  77                 goto fail;
  78         }
  79 -       hinfo->hash_version = root->info.hash_version;
  80 +       hinfo->hash_version = info->hash_version;
  81         if (hinfo->hash_version <= DX_HASH_TEA)
  82                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
  83         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
  84 @@ -400,27 +402,26 @@
  85                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
  86         hash = hinfo->hash;
  87
  88 -       if (root->info.unused_flags & 1) {
  89 +       if (info->unused_flags & 1) {
  90                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
  91 -                            root->info.unused_flags);
  92 +                            info->unused_flags);
  93                 brelse(bh);
  94                 *err = ERR_BAD_DX_DIR;
  95                 goto fail;
  96         }
  97
  98 -       if ((indirect = root->info.indirect_levels) > 1) {
  99 +       if ((indirect = info->indirect_levels) > 1) {
 100                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 101 -                            root->info.indirect_levels);
 102 +                            info->indirect_levels);
 103                 brelse(bh);
 104                 *err = ERR_BAD_DX_DIR;
 105                 goto fail;
 106         }
 107
 108 -       entries = (struct dx_entry *) (((char *)&root->info) +
 109 -                                      root->info.info_length);
 110 +       entries = (struct dx_entry *) (((char *)info) + info->info_length);
 111
 112         if (dx_get_limit(entries) != dx_root_limit(dir,
 113 -                                                  root->info.info_length)) {
 114 +                                                  info->info_length)) {
 115                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 116                 brelse(bh);
 117                 *err = ERR_BAD_DX_DIR;
 118 @@ -501,10 +502,12 @@
 119
 120  static void dx_release (struct dx_frame *frames)
 121  {
 122 +       struct dx_root_info *info;
 123         if (frames[0].bh == NULL)
 124                 return;
 125
 126 -       if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 127 +       info = dx_get_dx_info((struct ext4_dir_entry_2*)frames[0].bh->b_data);
 128 +       if (info->indirect_levels)
 129                 brelse(frames[1].bh);
 130         brelse(frames[0].bh);
 131  }
 132 @@ -1400,17 +1403,16 @@
 133         const char      *name = dentry->d_name.name;
 134         int             namelen = dentry->d_name.len;
 135         struct buffer_head *bh2;
 136 -       struct dx_root  *root;
 137         struct dx_frame frames[2], *frame;
 138         struct dx_entry *entries;
 139 -       struct ext4_dir_entry_2 *de, *de2;
 140 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 141         char            *data1, *top;
 142         unsigned        len;
 143         int             retval;
 144         unsigned        blocksize;
 145         struct dx_hash_info hinfo;
 146         ext4_lblk_t  block;
 147 -       struct fake_dirent *fde;
 148 +       struct dx_root_info *dx_info;
 149
 150         blocksize =  dir->i_sb->s_blocksize;
 151         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
 152 @@ -1420,18 +1422,19 @@
 153                 brelse(bh);
 154                 return retval;
 155         }
 156 -       root = (struct dx_root *) bh->b_data;
 157 +
 158 +       dot_de = (struct ext4_dir_entry_2 *) bh->b_data;
 159 +       dotdot_de = ext4_next_entry(dot_de, blocksize);
 160
 161         /* The 0th block becomes the root, move the dirents out */
 162 -       fde = &root->dotdot;
 163 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 164 -               ext4_rec_len_from_disk(fde->rec_len, blocksize));
 165 -       if ((char *) de >= (((char *) root) + blocksize)) {
 166 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 167 +               ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
 168 +       if ((char *) de >= (((char *) dot_de) + blocksize)) {
 169                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
 170                 brelse(bh);
 171                 return -EIO;
 172         }
 173 -       len = ((char *) root) + blocksize - (char *) de;
 174 +       len = ((char *) dot_de) + blocksize - (char *) de;
 175
 176         /* Allocate new block for the 0th block's dirents */
 177         bh2 = ext4_append(handle, dir, &block, &retval);
 178 @@ -1450,19 +1453,23 @@
 179         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
 180                                            blocksize);
 181         /* Initialize the root; the dot dirents already exist */
 182 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 183 -       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
 184 -                                          blocksize);
 185 -       memset (&root->info, 0, sizeof(root->info));
 186 -       root->info.info_length = sizeof(root->info);
 187 -       root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 188 -       entries = root->entries;
 189 +       dotdot_de->rec_len = ext4_rec_len_to_disk(blocksize -
 190 +                       le16_to_cpu(dot_de->rec_len), blocksize);
 191 +
 192 +       /* initialize hashing info */
 193 +       dx_info = dx_get_dx_info(dot_de);
 194 +       memset (dx_info, 0, sizeof(*dx_info));
 195 +       dx_info->info_length = sizeof(*dx_info);
 196 +       dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 197 +
 198 +       entries = (void *)dx_info + sizeof(*dx_info);
 199 +
 200         dx_set_block(entries, 1);
 201         dx_set_count(entries, 1);
 202 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
 203 +       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 204
 205         /* Initialize as for dx_probe */
 206 -       hinfo.hash_version = root->info.hash_version;
 207 +       hinfo.hash_version = dx_info->hash_version;
 208         if (hinfo.hash_version <= DX_HASH_TEA)
 209                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 210         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 211 @@ -1723,6 +1730,7 @@
 212                                 goto journal_error;
 213                         brelse (bh2);
 214                 } else {
 215 +                       struct dx_root_info * info;
 216                         dxtrace(printk(KERN_DEBUG
 217                                        "Creating second level index...\n"));
 218                         memcpy((char *) entries2, (char *) entries,
 219 @@ -1732,7 +1740,9 @@
 220                         /* Set up root */
 221                         dx_set_count(entries, 1);
 222                         dx_set_block(entries + 0, newblock);
 223 -                       ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
 224 +                       info = dx_get_dx_info((struct ext4_dir_entry_2*)
 225 +                                       frames[0].bh->b_data);
 226 +                       info->indirect_levels = 1;
 227
 228                         /* Add new access path frame */
 229                         frame = frames + 1;