[PATCH 10/14] loop: only freeze the queue in __loop_clr_fd when needed
From: Christoph Hellwig <hch@lst.de>
Date: 2022-03-25 06:40:36
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
->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@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Darrick J. Wong <djwong@kernel.org> --- drivers/block/loop.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c57acbcf9be6a..a5dd259958ee2 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c@@ -1144,8 +1144,13 @@ static void __loop_clr_fd(struct loop_device *lo, bool release) 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);
@@ -1170,7 +1175,8 @@ static void __loop_clr_fd(struct loop_device *lo, bool release) mapping_set_gfp_mask(filp->f_mapping, gfp); /* This is safe: open() is still holding a reference. */ module_put(THIS_MODULE); - 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);
--
2.30.2