FS-Cache: Mark cancellation of in-progress operation

Mark as cancelled an operation that is in progress rather than pending at the
time it is cancelled, and call fscache_complete_op() to cancel an operation so
that blocked ops can be started.

Signed-off-by: David Howells <dhowells@redhat.com>

fs/cachefiles/interface.c

@@ -484,7 +484,7 @@ static void cachefiles_invalidate_object(struct fscache_operation *op)
 		}
 	}
 
-	fscache_op_complete(op);
+	fscache_op_complete(op, true);
 	_leave("");
 }
 

fs/fscache/operation.c

@@ -363,9 +363,9 @@ void fscache_cancel_all_ops(struct fscache_object *object)
 }
 
 /*
- * Record the completion of an in-progress operation.
+ * Record the completion or cancellation of an in-progress operation.
  */
-void fscache_op_complete(struct fscache_operation *op)
+void fscache_op_complete(struct fscache_operation *op, bool cancelled)
 {
 	struct fscache_object *object = op->object;
 
@@ -380,7 +380,8 @@ void fscache_op_complete(struct fscache_operation *op)
 
 	spin_lock(&object->lock);
 
-	op->state = FSCACHE_OP_ST_COMPLETE;
+	op->state = cancelled ?
+		FSCACHE_OP_ST_CANCELLED : FSCACHE_OP_ST_COMPLETE;
 
 	if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
 		object->n_exclusive--;

fs/fscache/page.c

@@ -171,7 +171,7 @@ static void fscache_attr_changed_op(struct fscache_operation *op)
 			fscache_abort_object(object);
 	}
 
-	fscache_op_complete(op);
+	fscache_op_complete(op, true);
 	_leave("");
 }
 
@@ -704,7 +704,7 @@ static void fscache_write_op(struct fscache_operation *_op)
 		 * exists, so we should just cancel this write operation.
 		 */
 		spin_unlock(&object->lock);
-		op->op.state = FSCACHE_OP_ST_CANCELLED;
+		fscache_op_complete(&op->op, false);
 		_leave(" [inactive]");
 		return;
 	}
@@ -717,7 +717,7 @@ static void fscache_write_op(struct fscache_operation *_op)
 		 * cancel this write operation.
 		 */
 		spin_unlock(&object->lock);
-		op->op.state = FSCACHE_OP_ST_CANCELLED;
+		fscache_op_complete(&op->op, false);
 		_leave(" [cancel] op{f=%lx s=%u} obj{s=%u f=%lx}",
 		       _op->flags, _op->state, object->state, object->flags);
 		return;
@@ -755,7 +755,7 @@ static void fscache_write_op(struct fscache_operation *_op)
 	fscache_end_page_write(object, page);
 	if (ret < 0) {
 		fscache_abort_object(object);
-		fscache_op_complete(&op->op);
+		fscache_op_complete(&op->op, true);
 	} else {
 		fscache_enqueue_operation(&op->op);
 	}
@@ -770,7 +770,7 @@ superseded:
 	spin_unlock(&cookie->stores_lock);
 	clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
 	spin_unlock(&object->lock);
-	fscache_op_complete(&op->op);
+	fscache_op_complete(&op->op, true);
 	_leave("");
 }
 

include/linux/fscache-cache.h

@@ -116,7 +116,7 @@ extern atomic_t fscache_op_debug_id;
 extern void fscache_op_work_func(struct work_struct *work);
 
 extern void fscache_enqueue_operation(struct fscache_operation *);
-extern void fscache_op_complete(struct fscache_operation *);
+extern void fscache_op_complete(struct fscache_operation *, bool);
 extern void fscache_put_operation(struct fscache_operation *);
 
 /**
@@ -196,7 +196,7 @@ static inline void fscache_retrieval_complete(struct fscache_retrieval *op,
 {
 	op->n_pages -= n_pages;
 	if (op->n_pages <= 0)
-		fscache_op_complete(&op->op);
+		fscache_op_complete(&op->op, true);
 }
 
 /**