From 1fe0b1acb14dd3113b7dc975a118cd7f08af8316 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 30 Mar 2022 07:29:12 +0200 Subject: [PATCH] loop: only freeze the queue in __loop_clr_fd when needed ->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 Reviewed-by: Jan Kara Tested-by: Darrick J. Wong Link: https://lore.kernel.org/r/20220330052917.2566582-11-hch@lst.de Signed-off-by: Jens Axboe --- 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 d6315b0c413e..d1a4af599359 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1139,8 +1139,13 @@ 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); @@ -1165,7 +1170,8 @@ 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);