retry-storing-value-in-external-inode-with-xattr-block-too

   1 ext4: retry storing value in external inode with xattr block too
   2
   3 From: Tahsin Erdogan <tahsin@google.com>
   4
   5 When value size is <= EXT4_XATTR_MIN_LARGE_EA_SIZE(), and it
   6 doesn't fit in either inline or xattr block, a second try is made to
   7 store it in an external inode while storing the entry itself in inline
   8 area. There should also be an attempt to store the entry in xattr block.
   9
  10 This patch adds a retry loop to do that. It also makes the caller the
  11 sole decider on whether to store a value in an external inode.
  12
  13 Signed-off-by: Tahsin Erdogan <tahsin@google.com>
  14 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  15 ---
  16 v2: fix checkpatch.pl warning about indented retry_inode: label
  17
  18  fs/ext4/xattr.c | 35 ++++++++++++++++++-----------------
  19  1 file changed, 18 insertions(+), 17 deletions(-)
  20
  21 diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
  22 index dcf7ec98f138..0dfae3f8e209 100644
  23 --- a/fs/ext4/xattr.c
  24 +++ b/fs/ext4/xattr.c
  25 @@ -911,11 +911,6 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
  26         int in_inode = i->in_inode;
  27         int rc;
  28
  29 -       if (ext4_has_feature_ea_inode(inode->i_sb) &&
  30 -           (EXT4_XATTR_SIZE(i->value_len) >
  31 -            EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
  32 -               in_inode = 1;
  33 -
  34         /* Compute min_offs and last. */
  35         last = s->first;
  36         for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
  37 @@ -1097,7 +1092,8 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
  38  {
  39         struct super_block *sb = inode->i_sb;
  40         struct buffer_head *new_bh = NULL;
  41 -       struct ext4_xattr_search *s = &bs->s;
  42 +       struct ext4_xattr_search s_copy = bs->s;
  43 +       struct ext4_xattr_search *s = &s_copy;
  44         struct mb_cache_entry *ce = NULL;
  45         int error = 0;
  46         struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
  47 @@ -1519,6 +1515,11 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
  48                 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
  49                         goto cleanup;
  50
  51 +               if (ext4_has_feature_ea_inode(inode->i_sb) &&
  52 +                   (EXT4_XATTR_SIZE(i.value_len) >
  53 +                       EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
  54 +                       i.in_inode = 1;
  55 +retry_inode:
  56                 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
  57                 if (!error && !bs.s.not_found) {
  58                         i.value = NULL;
  59 @@ -1530,20 +1531,20 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
  60                                         goto cleanup;
  61                         }
  62                         error = ext4_xattr_block_set(handle, inode, &i, &bs);
  63 -                       if (ext4_has_feature_ea_inode(inode->i_sb) &&
  64 -                           error == -ENOSPC) {
  65 -                               /* xattr not fit to block, store at external
  66 -                                * inode */
  67 -                               i.in_inode = 1;
  68 -                               error = ext4_xattr_ibody_set(handle, inode,
  69 -                                                            &i, &is);
  70 -                       }
  71 -                       if (error)
  72 -                               goto cleanup;
  73 -                       if (!is.s.not_found) {
  74 +                       if (!error && !is.s.not_found) {
  75                                 i.value = NULL;
  76                                 error = ext4_xattr_ibody_set(handle, inode, &i,
  77                                                              &is);
  78 +                       } else if (error == -ENOSPC) {
  79 +                               /*
  80 +                                * Xattr does not fit in the block, store at
  81 +                                * external inode if possible.
  82 +                                */
  83 +                               if (ext4_has_feature_ea_inode(inode->i_sb) &&
  84 +                                   !i.in_inode) {
  85 +                                       i.in_inode = 1;
  86 +                                       goto retry_inode;
  87 +                               }
  88                         }
  89                 }
  90         }
  91 --
  92 2.13.1.611.g7e3b11ae1-goog
  93
  94