ldiskfs/kernel_patches/patches/rhel7.6/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: linux-3.10.0-123.9.3.el7.x86_64/fs/ext4/namei.c
   6 ===================================================================
   7 --- linux-3.10.0-123.9.3.el7.x86_64.orig/fs/ext4/namei.c
   8 +++ linux-3.10.0-123.9.3.el7.x86_64/fs/ext4/namei.c
   9 @@ -193,22 +193,13 @@ 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 @@ -511,6 +502,16 @@ 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 @@ -673,7 +674,7 @@ dx_probe(const struct qstr *d_name, stru
  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 @@ -684,17 +685,18 @@ dx_probe(const struct qstr *d_name, stru
  65                 *err = PTR_ERR(bh);
  66                 goto fail;
  67         }
  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 -               ext4_warning(dir->i_sb, "Unrecognised inode hash code %d for directory "
  73 -                             "#%lu", root->info.hash_version, dir->i_ino);
  74 +
  75 +       info = dx_get_dx_info((struct ext4_dir_entry_2 *)bh->b_data);
  76 +       if (info->hash_version != DX_HASH_TEA &&
  77 +           info->hash_version != DX_HASH_HALF_MD4 &&
  78 +           info->hash_version != DX_HASH_LEGACY) {
  79 +               ext4_warning(dir->i_sb, "inode #%lu: unrecognised hash code %u",
  80 +                            dir->i_ino, info->hash_version);
  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 @@ -702,28 +704,33 @@ dx_probe(const struct qstr *d_name, stru
  91                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
  92         hash = hinfo->hash;
  93
  94 -       if (root->info.unused_flags & 1) {
  95 -               ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
  96 -                            root->info.unused_flags);
  97 +       if (info->unused_flags & 1) {
  98 +               ext4_warning(dir->i_sb,
  99 +                            "inode #%lu: unimplemented hash flags: %#06x",
 100 +                            dir->i_ino, info->unused_flags);
 101                 brelse(bh);
 102                 *err = ERR_BAD_DX_DIR;
 103                 goto fail;
 104         }
 105
 106 -       if ((indirect = root->info.indirect_levels) > 1) {
 107 -               ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 108 -                            root->info.indirect_levels);
 109 +       indirect = info->indirect_levels;
 110 +       if (indirect > 1) {
 111 +               ext4_warning(dir->i_sb,
 112 +                            "inode #%lu: unimplemented hash depth %u",
 113 +                            dir->i_ino, info->indirect_levels);
 114                 brelse(bh);
 115                 *err = ERR_BAD_DX_DIR;
 116                 goto fail;
 117         }
 118
 119 -       entries = (struct dx_entry *) (((char *)&root->info) +
 120 -                                      root->info.info_length);
 121 +       entries = (struct dx_entry *)(((char *)info) + info->info_length);
 122
 123         if (dx_get_limit(entries) != dx_root_limit(dir,
 124 -                                                  root->info.info_length)) {
 125 -               ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 126 +                                                  info->info_length)) {
 127 +               ext4_warning(dir->i_sb, "dx entry: limit != root limit "
 128 +                            "inode #%lu: dx entry: limit %u != root limit %u",
 129 +                            dir->i_ino, dx_get_limit(entries),
 130 +                            dx_root_limit(dir, info->info_length));
 131                 brelse(bh);
 132                 *err = ERR_BAD_DX_DIR;
 133                 goto fail;
 134 @@ -807,10 +808,12 @@ fail:
 135
 136  static void dx_release (struct dx_frame *frames)
 137  {
 138 +       struct dx_root_info *info;
 139         if (frames[0].bh == NULL)
 140                 return;
 141
 142 -       if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 143 +       info = dx_get_dx_info((struct ext4_dir_entry_2 *)frames[0].bh->b_data);
 144 +       if (info->indirect_levels)
 145                 brelse(frames[1].bh);
 146         brelse(frames[0].bh);
 147  }
 148 @@ -1787,10 +1790,9 @@ static int make_indexed_dir(handle_t *ha
 149         const char      *name = dentry->d_name.name;
 150         int             namelen = dentry->d_name.len;
 151         struct buffer_head *bh2;
 152 -       struct dx_root  *root;
 153         struct dx_frame frames[2], *frame;
 154         struct dx_entry *entries;
 155 -       struct ext4_dir_entry_2 *de, *de2;
 156 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 157         struct ext4_dir_entry_tail *t;
 158         char            *data1, *top;
 159         unsigned        len;
 160 @@ -1798,7 +1800,7 @@ static int make_indexed_dir(handle_t *ha
 161         unsigned        blocksize;
 162         struct dx_hash_info hinfo;
 163         ext4_lblk_t  block;
 164 -       struct fake_dirent *fde;
 165 +       struct dx_root_info *dx_info;
 166         int             csum_size = 0;
 167
 168         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 169 @@ -1813,18 +1815,19 @@ static int make_indexed_dir(handle_t *ha
 170                 brelse(bh);
 171                 return retval;
 172         }
 173 -       root = (struct dx_root *) bh->b_data;
 174 +
 175 +       dot_de = (struct ext4_dir_entry_2 *)bh->b_data;
 176 +       dotdot_de = ext4_next_entry(dot_de, blocksize);
 177
 178         /* The 0th block becomes the root, move the dirents out */
 179 -       fde = &root->dotdot;
 180 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 181 -               ext4_rec_len_from_disk(fde->rec_len, blocksize));
 182 -       if ((char *) de >= (((char *) root) + blocksize)) {
 183 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 184 +               ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
 185 +       if ((char *)de >= (((char *)dot_de) + blocksize)) {
 186                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
 187                 brelse(bh);
 188                 return -EIO;
 189         }
 190 -       len = ((char *) root) + (blocksize - csum_size) - (char *) de;
 191 +       len = ((char *)dot_de) + (blocksize - csum_size) - (char *)de;
 192
 193         /* Allocate new block for the 0th block's dirents */
 194         bh2 = ext4_append(handle, dir, &block);
 195 @@ -1850,19 +1853,24 @@ static int make_indexed_dir(handle_t *ha
 196         }
 197
 198         /* Initialize the root; the dot dirents already exist */
 199 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 200 -       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
 201 -                                          blocksize);
 202 -       memset (&root->info, 0, sizeof(root->info));
 203 -       root->info.info_length = sizeof(root->info);
 204 -       root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 205 -       entries = root->entries;
 206 +       dotdot_de->rec_len =
 207 +               ext4_rec_len_to_disk(blocksize - le16_to_cpu(dot_de->rec_len),
 208 +                                    blocksize);
 209 +
 210 +       /* initialize hashing info */
 211 +       dx_info = dx_get_dx_info(dot_de);
 212 +       memset(dx_info, 0, sizeof(*dx_info));
 213 +       dx_info->info_length = sizeof(*dx_info);
 214 +       dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 215 +
 216 +       entries = (void *)dx_info + sizeof(*dx_info);
 217 +
 218         dx_set_block(entries, 1);
 219         dx_set_count(entries, 1);
 220 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
 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 @@ -2152,6 +2159,7 @@ 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 @@ -2161,7 +2169,9 @@ 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;