Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6

[safe/jmp/linux-2.6] / drivers / scsi / scsi_lib.c

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ba7e8ad..a82d2fe 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -536,6 +536,9 @@ static void scsi_run_queue(struct request_queue *q)
               !shost->host_blocked && !shost->host_self_blocked &&
                !((shost->can_queue > 0) &&
                  (shost->host_busy >= shost->can_queue))) {
+
+               int flagset;
+
                /*
                 * As long as shost is accepting commands and we have
                 * starved queues, call blk_run_queue. scsi_request_fn
@@ -549,19 +552,20 @@ static void scsi_run_queue(struct request_queue *q)
                sdev = list_entry(shost->starved_list.next,
                                          struct scsi_device, starved_entry);
                list_del_init(&sdev->starved_entry);
-               spin_unlock_irqrestore(shost->host_lock, flags);
-
+               spin_unlock(shost->host_lock);
+
+               spin_lock(sdev->request_queue->queue_lock);
+               flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
+                               !test_bit(QUEUE_FLAG_REENTER,
+                                       &sdev->request_queue->queue_flags);
+               if (flagset)
+                       queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue);
+               __blk_run_queue(sdev->request_queue);
+               if (flagset)
+                       queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue);
+               spin_unlock(sdev->request_queue->queue_lock);
 
-               if (test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
-                   !test_and_set_bit(QUEUE_FLAG_REENTER,
-                                     &sdev->request_queue->queue_flags)) {
-                       blk_run_queue(sdev->request_queue);
-                       clear_bit(QUEUE_FLAG_REENTER,
-                                 &sdev->request_queue->queue_flags);
-               } else
-                       blk_run_queue(sdev->request_queue);
-
-               spin_lock_irqsave(shost->host_lock, flags);
+               spin_lock(shost->host_lock);
                if (unlikely(!list_empty(&sdev->starved_entry)))
                        /*
                         * sdev lost a race, and was put back on the
@@ -1586,8 +1590,9 @@ struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
 
        blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
 
+       /* New queue, no concurrency on queue_flags */
        if (!shost->use_clustering)
-               clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
+               queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
 
        /*
         * set a reasonable default alignment on word boundaries: the