FS-Cache: Fix operation handling

fscache_submit_exclusive_op() adds an operation to the pending list if
other operations are pending.  Fix the check for pending ops as n_ops
must be greater than 0 at the point it is checked as it is incremented
immediately before under lock.

Signed-off-by: Akshat Aranya <aranya@nec-labs.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fscache/operation.c

@@ -101,7 +101,7 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
 		object->n_ops++;
 		object->n_exclusive++;	/* reads and writes must wait */
 
-		if (object->n_ops > 0) {
+		if (object->n_ops > 1) {
 			atomic_inc(&op->usage);
 			list_add_tail(&op->pend_link, &object->pending_ops);
 			fscache_stat(&fscache_n_op_pend);