[PATCH v2 3/3] scsi: ufs-bsg: complete ufs-bsg job only if no error

[Bean Huo (beanhuo)]

From: Bean Huo <beanhuo@xxxxxxxxxx>

In the case of UPIU/DME request execution failed in UFS device,
ufs_bsg_request() will complete this failed bsg job by calling
bsg_job_done(). Meanwhile, it returns this error status to blk-mq
layer, then triggers blk-mq completing this request again, this will
cause below panic.

Call trace:
ll_sc___cmpxchg_case_acq_32+0x4/0x20
complete+0x28/0x70
blk_end_sync_rq+0x24/0x30
blk_mq_end_request+0xb8/0x118
bsg_job_put+0x4c/0x58
bsg_complete+0x20/0x30
blk_done_softirq+0xb4/0xe8
do_softirq+0x154/0x3f0
run_ksoftirqd+0x4c/0x68
smpboot_thread_fn+0x22c/0x268
kthread+0x130/0x138
ret_from_fork+0x10/0x1c
Code: f84107fe d65f03c0 d503201f f9800011 (885ffc10)
---[ end trace d92825bff6326e66 ]---
Kernel panic - not syncing: Fatal exception in interrupt

This patch is to fix this issue. The solution is we complete
the ufs-bsg job only if no error happened.

Fixes: df032bf27a41 (scsi: ufs: Add a bsg endpoint that supports UPIUs)
Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx>
---
 drivers/scsi/ufs/ufs_bsg.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
index f420d6f8d84c..a9344eb4e047 100644
--- a/drivers/scsi/ufs/ufs_bsg.c
+++ b/drivers/scsi/ufs/ufs_bsg.c
@@ -149,7 +149,9 @@ static int ufs_bsg_request(struct bsg_job *job)
 out:
 	bsg_reply->result = ret;
 	job->reply_len = sizeof(struct ufs_bsg_reply);
-	bsg_job_done(job, ret, bsg_reply->reply_payload_rcv_len);
+	/* complete the job here only if no error */
+	if (ret == 0)
+		bsg_job_done(job, ret, bsg_reply->reply_payload_rcv_len);
 
 	return ret;
 }
-- 
2.7.4