FS-Cache: Reduce cookie ref count if submit fails.

I've been seeing issues with disposing cookies under vma pressure. The symptom
is that the refcount gets out of sync. In this case we fail to decrement the
refcount if submit fails. I found this while auditing the error in and around
cookie operations.

Signed-off-by: Milosz Tanski <milosz@adfin.com>
Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index d3b4539f16515451cdd691fd853927d00fa3f8a8..da032daf0e0d7562f40e5a050685829af68869ac 100644 (file)
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -982,6 +982,7 @@ nomem:
 submit_op_failed:
        clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
        spin_unlock(&cookie->lock);
+       fscache_unuse_cookie(object);
        kfree(op);
        _leave(" [EIO]");
        return transit_to(KILL_OBJECT);