->release is only called after all outstanding I/O has completed, so only
freeze the queue when clearing the backing file of a live loop device.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/block/loop.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d9a0e2205762f..fc0cdd1612b1d 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1110,7 +1110,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
return error;
}
-static void __loop_clr_fd(struct loop_device *lo)
+static void __loop_clr_fd(struct loop_device *lo, bool release)
{
struct file *filp;
gfp_t gfp = lo->old_gfp_mask;
@@ -1139,8 +1139,13 @@ static void __loop_clr_fd(struct loop_device *lo)
if (test_bit(QUEUE_FLAG_WC, &lo->lo_queue->queue_flags))
blk_queue_write_cache(lo->lo_queue, false, false);
- /* freeze request queue during the transition */
- blk_mq_freeze_queue(lo->lo_queue);
+ /*
+ * Freeze the request queue when unbinding on a live file descriptor and
+ * thus an open device. When called from ->release we are guaranteed
+ * that there is no I/O in progress already.
+ */
+ if (!release)
+ blk_mq_freeze_queue(lo->lo_queue);
destroy_workqueue(lo->workqueue);
loop_free_idle_workers(lo, true);
@@ -1163,7 +1168,8 @@ static void __loop_clr_fd(struct loop_device *lo)
/* let user-space know about this change */
kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE);
mapping_set_gfp_mask(filp->f_mapping, gfp);
- blk_mq_unfreeze_queue(lo->lo_queue);
+ if (!release)
+ blk_mq_unfreeze_queue(lo->lo_queue);
disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE);
@@ -1201,7 +1207,7 @@ static void loop_rundown_workfn(struct work_struct *work)
struct block_device *bdev = lo->lo_device;
struct gendisk *disk = lo->lo_disk;
- __loop_clr_fd(lo);
+ __loop_clr_fd(lo, true);
kobject_put(&bdev->bd_device.kobj);
module_put(disk->fops->owner);
loop_rundown_completed(lo);
@@ -1247,7 +1253,7 @@ static int loop_clr_fd(struct loop_device *lo)
lo->lo_state = Lo_rundown;
mutex_unlock(&lo->lo_mutex);
- __loop_clr_fd(lo);
+ __loop_clr_fd(lo, false);
loop_rundown_completed(lo);
return 0;
}
--
2.30.2
