block: add missing blk_queue_dead() checks

[deliverable/linux.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index 435af23786140cc4874c01342d7db5059b02d0d4..30add45a87efb1fdcfe066f22a6f48ab4790c1ed 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -358,7 +358,8 @@ EXPORT_SYMBOL(blk_put_queue);
 void blk_drain_queue(struct request_queue *q, bool drain_all)
 {
        while (true) {
-               int nr_rqs;
+               bool drain = false;
+               int i;
 
                spin_lock_irq(q->queue_lock);
 
@@ -368,14 +369,25 @@ void blk_drain_queue(struct request_queue *q, bool drain_all)
 
                __blk_run_queue(q);
 
-               if (drain_all)
-                       nr_rqs = q->rq.count[0] + q->rq.count[1];
-               else
-                       nr_rqs = q->rq.elvpriv;
+               drain |= q->rq.elvpriv;
+
+               /*
+                * Unfortunately, requests are queued at and tracked from
+                * multiple places and there's no single counter which can
+                * be drained.  Check all the queues and counters.
+                */
+               if (drain_all) {
+                       drain |= !list_empty(&q->queue_head);
+                       for (i = 0; i < 2; i++) {
+                               drain |= q->rq.count[i];
+                               drain |= q->in_flight[i];
+                               drain |= !list_empty(&q->flush_queue[i]);
+                       }
+               }
 
                spin_unlock_irq(q->queue_lock);
 
-               if (!nr_rqs)
+               if (!drain)
                        break;
                msleep(10);
        }
@@ -608,7 +620,7 @@ EXPORT_SYMBOL(blk_init_allocated_queue_node);
 
 int blk_get_queue(struct request_queue *q)
 {
-       if (likely(!test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+       if (likely(!blk_queue_dead(q))) {
                kobject_get(&q->kobj);
                return 0;
        }
@@ -755,7 +767,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
        const bool is_sync = rw_is_sync(rw_flags) != 0;
        int may_queue;
 
-       if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+       if (unlikely(blk_queue_dead(q)))
                return NULL;
 
        may_queue = elv_may_queue(q, rw_flags);
@@ -875,7 +887,7 @@ static struct request *get_request_wait(struct request_queue *q, int rw_flags,
                struct io_context *ioc;
                struct request_list *rl = &q->rq;
 
-               if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+               if (unlikely(blk_queue_dead(q)))
                        return NULL;
 
                prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
@@ -1719,6 +1731,10 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
                return -EIO;
 
        spin_lock_irqsave(q->queue_lock, flags);
+       if (unlikely(blk_queue_dead(q))) {
+               spin_unlock_irqrestore(q->queue_lock, flags);
+               return -ENODEV;
+       }
 
        /*
         * Submitting request must be dequeued before calling this function
@@ -2692,6 +2708,14 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth,
 {
        trace_block_unplug(q, depth, !from_schedule);
 
+       /*
+        * Don't mess with dead queue.
+        */
+       if (unlikely(blk_queue_dead(q))) {
+               spin_unlock(q->queue_lock);
+               return;
+       }
+
        /*
         * If we are punting this to kblockd, then we can safely drop
         * the queue_lock before waking kblockd (which needs to take
@@ -2768,6 +2792,15 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
                        depth = 0;
                        spin_lock(q->queue_lock);
                }
+
+               /*
+                * Short-circuit if @q is dead
+                */
+               if (unlikely(blk_queue_dead(q))) {
+                       __blk_end_request_all(rq, -ENODEV);
+                       continue;
+               }
+
                /*
                 * rq is already accounted, so use raw insert
                 */