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-rw-r--r--drivers/block/virtio_blk.c22
1 files changed, 21 insertions, 1 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index a345e40e1bc..ba73661fb9f 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -4,6 +4,7 @@
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/virtio.h>
#include <linux/virtio_blk.h>
#include <linux/scatterlist.h>
@@ -36,6 +37,12 @@ struct virtio_blk
/* Process context for config space updates */
struct work_struct config_work;
+ /* Lock for config space updates */
+ struct mutex config_lock;
+
+ /* enable config space updates */
+ bool config_enable;
+
/* What host tells us, plus 2 for header & tailer. */
unsigned int sg_elems;
@@ -318,6 +325,10 @@ static void virtblk_config_changed_work(struct work_struct *work)
char cap_str_2[10], cap_str_10[10];
u64 capacity, size;
+ mutex_lock(&vblk->config_lock);
+ if (!vblk->config_enable)
+ goto done;
+
/* Host must always specify the capacity. */
vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
&capacity, sizeof(capacity));
@@ -340,6 +351,8 @@ static void virtblk_config_changed_work(struct work_struct *work)
cap_str_10, cap_str_2);
set_capacity(vblk->disk, capacity);
+done:
+ mutex_unlock(&vblk->config_lock);
}
static void virtblk_config_changed(struct virtio_device *vdev)
@@ -388,7 +401,9 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->vdev = vdev;
vblk->sg_elems = sg_elems;
sg_init_table(vblk->sg, vblk->sg_elems);
+ mutex_init(&vblk->config_lock);
INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
+ vblk->config_enable = true;
/* We expect one virtqueue, for output. */
vblk->vq = virtio_find_single_vq(vdev, blk_done, "requests");
@@ -542,7 +557,10 @@ static void __devexit virtblk_remove(struct virtio_device *vdev)
struct virtio_blk *vblk = vdev->priv;
int index = vblk->index;
- flush_work(&vblk->config_work);
+ /* Prevent config work handler from accessing the device. */
+ mutex_lock(&vblk->config_lock);
+ vblk->config_enable = false;
+ mutex_unlock(&vblk->config_lock);
/* Nothing should be pending. */
BUG_ON(!list_empty(&vblk->reqs));
@@ -550,6 +568,8 @@ static void __devexit virtblk_remove(struct virtio_device *vdev)
/* Stop all the virtqueues. */
vdev->config->reset(vdev);
+ flush_work(&vblk->config_work);
+
del_gendisk(vblk->disk);
blk_cleanup_queue(vblk->disk->queue);
put_disk(vblk->disk);