[PATCH v3 3/8] scsi: core: Support failing requests while recovering

Bart Van Assche
2022-09-29T22:01:03Z

The current behavior for SCSI commands submitted while error recovery
is ongoing is to retry command submission after error recovery has
finished. See also the scsi_host_in_recovery() check in
scsi_host_queue_ready(). Add support for failing SCSI commands while
host recovery is in progress. This functionality will be used to fix a
deadlock in the UFS driver.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/scsi_lib.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 473d9403f0c1..ecd2ce3815df 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1337,9 +1337,6 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
struct scsi_device *sdev,
struct scsi_cmnd *cmd)
{
- if (scsi_host_in_recovery(shost))
- return 0;
-
if (atomic_read(&shost->host_blocked) > 0) {
if (scsi_host_busy(shost) > 0)
goto starved;
@@ -1727,6 +1724,11 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
ret = BLK_STS_RESOURCE;
if (!scsi_target_queue_ready(shost, sdev))
goto out_put_budget;
+ if (unlikely(scsi_host_in_recovery(shost))) {
+ if (req->cmd_flags & REQ_FAILFAST_MASK)
+ ret = BLK_STS_OFFLINE;
+ goto out_dec_target_busy;
+ }
if (!scsi_host_queue_ready(q, shost, sdev, cmd))
goto out_dec_target_busy;