1 files changed, 54 insertions, 28 deletions

diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index 09e43b6e822f..296492efb81b 100644
--- a/fs/fscache/operation.c
+++ b/fs/fscache/operation.c
@@ -34,32 +34,31 @@ void fscache_enqueue_operation(struct fscache_operation *op)
 
         fscache_set_op_state(op, "EnQ");
 
+        ASSERT(list_empty(&op->pend_link));
         ASSERT(op->processor != NULL);
         ASSERTCMP(op->object->state, >=, FSCACHE_OBJECT_AVAILABLE);
         ASSERTCMP(atomic_read(&op->usage), >, 0);
 
-        if (list_empty(&op->pend_link)) {
-                switch (op->flags & FSCACHE_OP_TYPE) {
-                case FSCACHE_OP_FAST:
-                        _debug("queue fast");
-                        atomic_inc(&op->usage);
-                        if (!schedule_work(&op->fast_work))
-                                fscache_put_operation(op);
-                        break;
-                case FSCACHE_OP_SLOW:
-                        _debug("queue slow");
-                        slow_work_enqueue(&op->slow_work);
-                        break;
-                case FSCACHE_OP_MYTHREAD:
-                        _debug("queue for caller's attention");
-                        break;
-                default:
-                        printk(KERN_ERR "FS-Cache: Unexpected op type %lx",
-                               op->flags);
-                        BUG();
-                        break;
-                }
-                fscache_stat(&fscache_n_op_enqueue);
+        fscache_stat(&fscache_n_op_enqueue);
+        switch (op->flags & FSCACHE_OP_TYPE) {
+        case FSCACHE_OP_FAST:
+                _debug("queue fast");
+                atomic_inc(&op->usage);
+                if (!schedule_work(&op->fast_work))
+                        fscache_put_operation(op);
+                break;
+        case FSCACHE_OP_SLOW:
+                _debug("queue slow");
+                slow_work_enqueue(&op->slow_work);
+                break;
+        case FSCACHE_OP_MYTHREAD:
+                _debug("queue for caller's attention");
+                break;
+        default:
+                printk(KERN_ERR "FS-Cache: Unexpected op type %lx",
+                       op->flags);
+                BUG();
+                break;
         }
 }
 EXPORT_SYMBOL(fscache_enqueue_operation);
@@ -97,6 +96,7 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
         spin_lock(&object->lock);
         ASSERTCMP(object->n_ops, >=, object->n_in_progress);
         ASSERTCMP(object->n_ops, >=, object->n_exclusive);
+        ASSERT(list_empty(&op->pend_link));
 
         ret = -ENOBUFS;
         if (fscache_object_is_active(object)) {
@@ -202,6 +202,7 @@ int fscache_submit_op(struct fscache_object *object,
         spin_lock(&object->lock);
         ASSERTCMP(object->n_ops, >=, object->n_in_progress);
         ASSERTCMP(object->n_ops, >=, object->n_exclusive);
+        ASSERT(list_empty(&op->pend_link));
 
         ostate = object->state;
         smp_rmb();
@@ -273,12 +274,7 @@ void fscache_start_operations(struct fscache_object *object)
                         stop = true;
                 }
                 list_del_init(&op->pend_link);
-                object->n_in_progress++;
-
-                if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
-                        wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
-                if (op->processor)
-                        fscache_enqueue_operation(op);
+                fscache_run_op(object, op);
 
                 /* the pending queue was holding a ref on the object */
                 fscache_put_operation(op);
@@ -291,6 +287,36 @@ void fscache_start_operations(struct fscache_object *object)
 }
 
 /*
+ * cancel an operation that's pending on an object
+ */
+int fscache_cancel_op(struct fscache_operation *op)
+{
+        struct fscache_object *object = op->object;
+        int ret;
+
+        _enter("OBJ%x OP%x}", op->object->debug_id, op->debug_id);
+
+        spin_lock(&object->lock);
+
+        ret = -EBUSY;
+        if (!list_empty(&op->pend_link)) {
+                fscache_stat(&fscache_n_op_cancelled);
+                list_del_init(&op->pend_link);
+                object->n_ops--;
+                if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
+                        object->n_exclusive--;
+                if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
+                        wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
+                fscache_put_operation(op);
+                ret = 0;
+        }
+
+        spin_unlock(&object->lock);
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
  * release an operation
  * - queues pending ops if this is the last in-progress op
  */