diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index c811793..dcb3e1d 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -288,6 +288,7 @@
 static inline void fscache_raise_event(struct fscache_object *object,
 				       unsigned event)
 {
+	BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 	if (!test_and_set_bit(event, &object->events) &&
 	    test_bit(event, &object->event_mask))
 		fscache_enqueue_object(object);
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 2ef8a08..2c512cb 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -103,6 +103,7 @@
 {
 	enum fscache_object_state new_state;
 	struct fscache_cookie *cookie;
+	int event;
 
 	ASSERT(object != NULL);
 
@@ -275,7 +276,8 @@
 
 	/* determine the transition from a lookup state */
 lookup_transit:
-	switch (fls(object->events & object->event_mask) - 1) {
+	event = fls(object->events & object->event_mask) - 1;
+	switch (event) {
 	case FSCACHE_OBJECT_EV_WITHDRAW:
 	case FSCACHE_OBJECT_EV_RETIRE:
 	case FSCACHE_OBJECT_EV_RELEASE:
@@ -292,7 +294,8 @@
 
 	/* determine the transition from an active state */
 active_transit:
-	switch (fls(object->events & object->event_mask) - 1) {
+	event = fls(object->events & object->event_mask) - 1;
+	switch (event) {
 	case FSCACHE_OBJECT_EV_WITHDRAW:
 	case FSCACHE_OBJECT_EV_RETIRE:
 	case FSCACHE_OBJECT_EV_RELEASE:
@@ -314,7 +317,8 @@
 
 	/* determine the transition from a terminal state */
 terminal_transit:
-	switch (fls(object->events & object->event_mask) - 1) {
+	event = fls(object->events & object->event_mask) - 1;
+	switch (event) {
 	case FSCACHE_OBJECT_EV_WITHDRAW:
 		new_state = FSCACHE_OBJECT_WITHDRAWING;
 		goto change_state;
@@ -347,8 +351,8 @@
 
 unsupported_event:
 	printk(KERN_ERR "FS-Cache:"
-	       " Unsupported event %lx [mask %lx] in state %s\n",
-	       object->events, object->event_mask,
+	       " Unsupported event %d [%lx/%lx] in state %s\n",
+	       event, object->events, object->event_mask,
 	       fscache_object_states[object->state]);
 	BUG();
 }
@@ -945,7 +949,7 @@
 
 	spin_lock(&cookie->lock);
 	if (fscache_submit_exclusive_op(object, op) < 0)
-		BUG();
+		goto submit_op_failed;
 	spin_unlock(&cookie->lock);
 	fscache_put_operation(op);
 
@@ -960,4 +964,11 @@
 	 */
 	fscache_invalidation_complete(cookie);
 	_leave("");
+	return;
+
+submit_op_failed:
+	spin_unlock(&cookie->lock);
+	kfree(op);
+	fscache_raise_event(object, FSCACHE_OBJECT_EV_ERROR);
+	_leave(" [EIO]");
 }
diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index c58dbe6..9e6b7d2 100644
--- a/fs/fscache/operation.c
+++ b/fs/fscache/operation.c
@@ -84,6 +84,8 @@
 int fscache_submit_exclusive_op(struct fscache_object *object,
 				struct fscache_operation *op)
 {
+	int ret;
+
 	_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);
 
 	ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);
@@ -116,6 +118,7 @@
 
 		/* need to issue a new write op after this */
 		clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
+		ret = 0;
 	} else if (object->state == FSCACHE_OBJECT_CREATING) {
 		op->object = object;
 		object->n_ops++;
@@ -123,13 +126,17 @@
 		atomic_inc(&op->usage);
 		list_add_tail(&op->pend_link, &object->pending_ops);
 		fscache_stat(&fscache_n_op_pend);
+		ret = 0;
 	} else {
-		/* not allowed to submit ops in any other state */
-		BUG();
+		/* If we're in any other state, there must have been an I/O
+		 * error of some nature.
+		 */
+		ASSERT(test_bit(FSCACHE_IOERROR, &object->cache->flags));
+		ret = -EIO;
 	}
 
 	spin_unlock(&object->lock);
-	return 0;
+	return ret;
 }
 
 /*