Btrfs: use kmem_cache_free when freeing entry in inode cache

commit c3f4a1685bb87e59c886ee68f7967eae07d4dffa upstream.

The free space entries are allocated using kmem_cache_zalloc(),
through __btrfs_add_free_space(), therefore we should use
kmem_cache_free() and not kfree() to avoid any confusion and
any potential problem. Looking at the kfree() definition at
mm/slab.c it has the following comment:

  /*
   * (...)
   *
   * Don't free memory not originally allocated by kmalloc()
   * or you will run into trouble.
   */

So better be safe and use kmem_cache_free().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index a1fee6f..41eac47 100644 (file)
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -269,7 +269,7 @@ void btrfs_unpin_free_ino(struct btrfs_root *root)
                __btrfs_add_free_space(ctl, info->offset, count);
 free:
                rb_erase(&info->offset_index, rbroot);
-               kfree(info);
+               kmem_cache_free(btrfs_free_space_cachep, info);
        }
 }