It turned out that there is no need to call blk_mq_freeze_queue() from
lo_release(), for all pending I/O requests are flushed by the block core
layer before "struct block_device_operations"->release() is called.
As a preparation for not holding lo->lo_mutex from lo_open()/lo_release()
paths, remove blk_mq_freeze_queue()/blk_mq_unfreeze_queue() from
lo_release().
Cc: Jan Kara <jack@xxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/loop.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 14b6f862531b..b6435f803061 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1108,7 +1108,8 @@ static void __loop_clr_fd(struct loop_device *lo, bool release)
blk_queue_write_cache(lo->lo_queue, false, false);
/* freeze request queue during the transition */
- blk_mq_freeze_queue(lo->lo_queue);
+ if (!release)
+ blk_mq_freeze_queue(lo->lo_queue);
destroy_workqueue(lo->workqueue);
spin_lock_irq(&lo->lo_work_lock);
@@ -1139,7 +1140,8 @@ static void __loop_clr_fd(struct loop_device *lo, bool release)
/* 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);
@@ -1728,22 +1730,11 @@ static void lo_release(struct gendisk *disk, fmode_t mode)
goto out_unlock;
lo->lo_state = Lo_rundown;
mutex_unlock(&lo->lo_mutex);
- /*
- * In autoclear mode, stop the loop thread
- * and remove configuration after last close.
- */
__loop_clr_fd(lo, true);
mutex_lock(&lo->lo_mutex);
lo->lo_state = Lo_unbound;
mutex_unlock(&lo->lo_mutex);
return;
- } else if (lo->lo_state == Lo_bound) {
- /*
- * Otherwise keep thread (if running) and config,
- * but flush possible ongoing bios in thread.
- */
- blk_mq_freeze_queue(lo->lo_queue);
- blk_mq_unfreeze_queue(lo->lo_queue);
}
out_unlock:
--
2.32.0
