[PATCH v4 06/25] virtio-blk: drop config_mutex

Michael S. Tsirkin
2014-10-13T07:50:14Z

config_mutex served two purposes: prevent multiple concurrent config
change handlers, and synchronize access to config_enable flag.

Since commit dbf2576e37da0fcc7aacbfbb9fd5d3de7888a3c1
workqueue: make all workqueues non-reentrant
all workqueues are non-reentrant, and config_enable
is now gone.

Get rid of the unnecessary lock.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
drivers/block/virtio_blk.c | 8 --------
1 file changed, 8 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 91272f1a..89ba8d6 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -41,9 +41,6 @@ struct virtio_blk
/* Process context for config space updates */
struct work_struct config_work;

- /* Lock for config space updates */
- struct mutex config_lock;
-
/* What host tells us, plus 2 for header & tailer. */
unsigned int sg_elems;

@@ -344,8 +341,6 @@ static void virtblk_config_changed_work(struct work_struct *work)
char *envp[] = { "RESIZE=1", NULL };
u64 capacity, size;

- mutex_lock(&vblk->config_lock);
-
/* Host must always specify the capacity. */
virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);

@@ -369,8 +364,6 @@ static void virtblk_config_changed_work(struct work_struct *work)
set_capacity(vblk->disk, capacity);
revalidate_disk(vblk->disk);
kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
-
- mutex_unlock(&vblk->config_lock);
}

static void virtblk_config_changed(struct virtio_device *vdev)
@@ -601,7 +594,6 @@ static int virtblk_probe(struct virtio_device *vdev)

vblk->vdev = vdev;
vblk->sg_elems = sg_elems;
- mutex_init(&vblk->config_lock);

INIT_WORK(&vblk->config_work, virtblk_config_changed_work);

--
MST