From e5eb7048e3552717b55005d7be6a7fd9534d5465 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sat, 30 Jul 2022 10:03:46 +0000 Subject: [PATCH] scsi: core: Fix race between handling STS_RESOURCE and completion mainline inclusion from mainline-v5.10 commit 673235f915318ced5d7ec4b2bfd8cb909e6a4a55 category: bugfix bugzilla: 187359, https://gitee.com/openeuler/kernel/issues/I5JQFO CVE: NA -------------------------------- When queuing I/O request to LLD, STS_RESOURCE may be returned because: - Host is in recovery or blocked - Target queue throttling or target is blocked - LLD rejection In these scenarios BLK_STS_DEV_RESOURCE is returned to the block layer to avoid an unnecessary re-run of the queue. However, all of the requests queued to this SCSI device may complete immediately after reading 'sdev->device_busy' and BLK_STS_DEV_RESOURCE is returned to block layer. In that case the current I/O won't get a chance to get queued since it is invisible at that time for both scsi_run_queue_async() and blk-mq's RESTART. Fix the issue by not returning BLK_STS_DEV_RESOURCE in this situation. Link: https://lore.kernel.org/r/20201202100419.525144-1-ming.lei@redhat.com Fixes: 86ff7c2a80cd ("blk-mq: introduce BLK_STS_DEV_RESOURCE") Cc: Hannes Reinecke Cc: Sumit Saxena Cc: Kashyap Desai Cc: Bart Van Assche Cc: Ewan Milne Cc: Long Li Reported-by: John Garry Tested-by: "chenxiang (M)" Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen Signed-off-by: Yu Kuai Reviewed-by: Jason Yan Signed-off-by: Yongqiang Liu --- drivers/scsi/scsi_lib.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 5c6e05bbcb68..719cdf5628ec 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2233,8 +2233,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, case BLK_STS_OK: break; case BLK_STS_RESOURCE: - if (atomic_read(&sdev->device_busy) || - scsi_device_blocked(sdev)) + if (scsi_device_blocked(sdev)) ret = BLK_STS_DEV_RESOURCE; break; default: -- GitLab