[RFC PATCH 5/5] virtio-blk: Use block layer provided spinlock
From: Asias He <hidden>
Date: 2012-05-21 09:08:33
Also in:
kvm
Subsystem:
block layer, the rest, virtio block and scsi drivers, virtio core · Maintainers:
Jens Axboe, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Block layer will allocate a spinlock for the queue if the driver does
not provide one in blk_init_queue().
The reason to use the internal spinlock is that blk_cleanup_queue() will
switch to use the internal spinlock in the cleanup code path.
if (q->queue_lock != &q->__queue_lock)
q->queue_lock = &q->__queue_lock;
However, processes which are in D state might have taken the driver
provided spinlock, when the processes wake up , they would release the
block provided spinlock.
=====================================
[ BUG: bad unlock balance detected! ]
3.4.0-rc7+ #238 Not tainted
-------------------------------------
fio/3587 is trying to release lock (&(&q->__queue_lock)->rlock) at:
[<ffffffff813274d2>] blk_queue_bio+0x2a2/0x380
but there are no more locks to release!
other info that might help us debug this:
1 lock held by fio/3587:
#0: (&(&vblk->lock)->rlock){......}, at:
[<ffffffff8132661a>] get_request_wait+0x19a/0x250
Cc: Rusty Russell <redacted>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <redacted>
---
drivers/block/virtio_blk.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index ba35509..0c2f0e8 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c@@ -21,8 +21,6 @@ struct workqueue_struct *virtblk_wq; struct virtio_blk { - spinlock_t lock; - struct virtio_device *vdev; struct virtqueue *vq;
@@ -65,7 +63,7 @@ static void blk_done(struct virtqueue *vq) unsigned int len; unsigned long flags; - spin_lock_irqsave(&vblk->lock, flags); + spin_lock_irqsave(vblk->disk->queue->queue_lock, flags); while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) { int error;
@@ -99,7 +97,7 @@ static void blk_done(struct virtqueue *vq) } /* In case queue is stopped waiting for more buffers. */ blk_start_queue(vblk->disk->queue); - spin_unlock_irqrestore(&vblk->lock, flags); + spin_unlock_irqrestore(vblk->disk->queue->queue_lock, flags); } static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
@@ -456,7 +454,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) goto out_free_index; } - spin_lock_init(&vblk->lock); vblk->vdev = vdev; vblk->sg_elems = sg_elems; sg_init_table(vblk->sg, vblk->sg_elems);
@@ -481,7 +478,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) goto out_mempool; } - q = vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock); + q = vblk->disk->queue = blk_init_queue(do_virtblk_request, NULL); if (!q) { err = -ENOMEM; goto out_put_disk;
--
1.7.10.1