btrfs: increment ctx->pos for every emitted or skipped dirent in readdir

If we process the last item in the leaf and hit an I/O error while
reading the next leaf, we return -EIO without having adjusted the
position.  Since we have emitted dirents, getdents() will return
the byte count to the user instead of the error.  Subsequent callers
will emit the last successful dirent again, and return -EIO again,
with the same result.  Callers loop forever.

Instead, if we always increment ctx->pos after emitting or skipping
the dirent, we'll be sure that we won't hit the same one again.  When
we go to process the next leaf, we won't have emitted any dirents
and the -EIO will be returned to the user properly.  We also don't
need to track if we've emitted a dirent already or if we've changed
the position yet.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 0fcf5f25d524..d90d4446f9fe 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -1686,7 +1686,7 @@ int btrfs_should_delete_dir_index(struct list_head *del_list,
  *
  */
 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
-				    struct list_head *ins_list, bool *emitted)
+				    struct list_head *ins_list)
 {
 	struct btrfs_dir_item *di;
 	struct btrfs_delayed_item *curr, *next;
@@ -1730,7 +1730,6 @@ int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
 
 		if (over)
 			return 1;
-		*emitted = true;
 	}
 	return 0;
 }