ldiskfs/kernel_patches/patches/sles12sp2/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 dx_frame *frame = frame_in;
  62         u32 hash;
  63
  64 @@ -684,17 +685,17 @@ dx_probe(const struct qstr *d_name, stru
  65         if (IS_ERR(frame->bh))
  66                 return (struct dx_frame *) frame->bh;
  67
  68 -       root = (struct dx_root *) frame->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 +       info = dx_get_dx_info((struct ext4_dir_entry_2 *)frame->bh->b_data);
  73 +       if (info->hash_version != DX_HASH_TEA &&
  74 +           info->hash_version != DX_HASH_HALF_MD4 &&
  75 +           info->hash_version != DX_HASH_LEGACY) {
  76                 ext4_warning_inode(dir, "Unrecognised inode hash code %u for directory "
  77 -                                  "%lu", root->info.hash_version, dir->i_ino);
  78 +                                  "%lu", info->hash_version, dir->i_ino);
  79                 goto fail;
  80         }
  81         if (fname)
  82                 hinfo = &fname->hinfo;
  83 -       hinfo->hash_version = root->info.hash_version;
  84 +       hinfo->hash_version = info->hash_version;
  85         if (hinfo->hash_version <= DX_HASH_TEA)
  86                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
  87         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
  88 @@ -702,27 +704,26 @@ dx_probe(const struct qstr *d_name, stru
  89                 ext4fs_dirhash(d_name->name, 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_inode(dir, "Unimplemented hash flags: %#06x",
  95 -                                  root->info.unused_flags);
  96 +                                  info->unused_flags);
  97                 goto fail;
  98         }
  99
 100 -       indirect = root->info.indirect_levels;
 101 +       indirect = info->indirect_levels;
 102         if (indirect > 1) {
 103                 ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
 104 -                                  root->info.indirect_levels);
 105 +                                  info->indirect_levels);
 106                 goto fail;
 107         }
 108
 109 -       entries = (struct dx_entry *)(((char *)&root->info) +
 110 -                                     root->info.info_length);
 111 +       entries = (struct dx_entry *)(((char *)info) + info->info_length);
 112
 113         if (dx_get_limit(entries) != dx_root_limit(dir,
 114 -                                                  root->info.info_length)) {
 115 +                                                  info->info_length)) {
 116                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 117                                    dx_get_limit(entries),
 118 -                                  dx_root_limit(dir, root->info.info_length));
 119 +                                  dx_root_limit(dir, info->info_length));
 120                 goto fail;
 121         }
 122
 123 @@ -1787,10 +1790,9 @@ static int make_indexed_dir(handle_t *ha
 124         const char      *name = dentry->d_name.name;
 125         int             namelen = dentry->d_name.len;
 126         struct buffer_head *bh2;
 127 -       struct dx_root  *root;
 128         struct dx_frame frames[2], *frame;
 129         struct dx_entry *entries;
 130 -       struct ext4_dir_entry_2 *de, *de2;
 131 +       struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
 132         struct ext4_dir_entry_tail *t;
 133         char            *data1, *top;
 134         unsigned        len;
 135 @@ -1798,7 +1800,7 @@ static int make_indexed_dir(handle_t *ha
 136         unsigned        blocksize;
 137         struct dx_hash_info hinfo;
 138         ext4_lblk_t  block;
 139 -       struct fake_dirent *fde;
 140 +       struct dx_root_info *dx_info;
 141         int csum_size = 0;
 142
 143         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 144 @@ -1813,18 +1815,19 @@ static int make_indexed_dir(handle_t *ha
 145                 brelse(bh);
 146                 return retval;
 147         }
 148 -       root = (struct dx_root *) bh->b_data;
 149 +
 150 +       dot_de = (struct ext4_dir_entry_2 *)bh->b_data;
 151 +       dotdot_de = ext4_next_entry(dot_de, blocksize);
 152
 153         /* The 0th block becomes the root, move the dirents out */
 154 -       fde = &root->dotdot;
 155 -       de = (struct ext4_dir_entry_2 *)((char *)fde +
 156 -               ext4_rec_len_from_disk(fde->rec_len, blocksize));
 157 -       if ((char *) de >= (((char *) root) + blocksize)) {
 158 +       de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
 159 +               ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
 160 +       if ((char *)de >= (((char *)dot_de) + blocksize)) {
 161                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
 162                 brelse(bh);
 163                 return -EFSCORRUPTED;
 164         }
 165 -       len = ((char *) root) + (blocksize - csum_size) - (char *) de;
 166 +       len = ((char *)dot_de) + (blocksize - csum_size) - (char *)de;
 167
 168         /* Allocate new block for the 0th block's dirents */
 169         bh2 = ext4_append(handle, dir, &block);
 170 @@ -1850,19 +1853,24 @@ static int make_indexed_dir(handle_t *ha
 171         }
 172
 173         /* Initialize the root; the dot dirents already exist */
 174 -       de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 175 -       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
 176 -                                          blocksize);
 177 -       memset (&root->info, 0, sizeof(root->info));
 178 -       root->info.info_length = sizeof(root->info);
 179 -       root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 180 -       entries = root->entries;
 181 +       dotdot_de->rec_len =
 182 +               ext4_rec_len_to_disk(blocksize - le16_to_cpu(dot_de->rec_len),
 183 +                                    blocksize);
 184 +
 185 +       /* initialize hashing info */
 186 +       dx_info = dx_get_dx_info(dot_de);
 187 +       memset(dx_info, 0, sizeof(*dx_info));
 188 +       dx_info->info_length = sizeof(*dx_info);
 189 +       dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 190 +
 191 +       entries = (void *)dx_info + sizeof(*dx_info);
 192 +
 193         dx_set_block(entries, 1);
 194         dx_set_count(entries, 1);
 195 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
 196 +       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 197
 198         /* Initialize as for dx_probe */
 199 -       fname->hinfo.hash_version = root->info.hash_version;
 200 +       fname->hinfo.hash_version = dx_info->hash_version;
 201         if (fname->hinfo.hash_version <= DX_HASH_TEA)
 202                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 203         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 204 @@ -2152,6 +2159,7 @@ static int ext4_dx_add_entry(handle_t *h
 205                                 goto journal_error;
 206                         brelse (bh2);
 207                 } else {
 208 +                       struct dx_root_info *info;
 209                         dxtrace(printk(KERN_DEBUG
 210                                        "Creating second level index...\n"));
 211                         memcpy((char *) entries2, (char *) entries,
 212 @@ -2161,7 +2169,9 @@ static int ext4_dx_add_entry(handle_t *h
 213                         /* Set up root */
 214                         dx_set_count(entries, 1);
 215                         dx_set_block(entries + 0, newblock);
 216 -                       ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
 217 +                       info = dx_get_dx_info((struct ext4_dir_entry_2 *)
 218 +                                             frames[0].bh->b_data);
 219 +                       info->indirect_levels = 1;
 220
 221                         /* Add new access path frame */
 222                         frame = frames + 1;