From: Steffen Maier <maier@linux.ibm.com>
Date: Wed, 7 Aug 2019 16:49:48 +0200
Subject: [PATCH] scsi: core: fix dh and multipathing for SCSI hosts without
request batching
Git-commit: 6b6fa7a5c86e1269d9f0c9a5b902072351317387
References: bsc#1156419,jsc#SLE-8281
Patch-Mainline: v5.4-rc5
This was missing from scsi_device_from_queue() due to the introduction of
another new scsi_mq_ops_no_commit of linux-next commit 8930a6c20791 ("scsi:
core: add support for request batching") from Martin's scsi/5.4/scsi-queue
or James' scsi/misc.
Only devicehandler code seems to call scsi_device_from_queue():
drivers/scsi/scsi_dh.c:
scsi_dh_activate[255] sdev = scsi_device_from_queue(q);
scsi_dh_set_params[302] sdev = scsi_device_from_queue(q);
scsi_dh_attach[325] sdev = scsi_device_from_queue(q);
scsi_dh_attached_handler_name[363] sdev = scsi_device_from_queue(q);
Fixes multipath tools follow-on errors:
$ multipath -v6
...
libdevmapper: ioctl/libdm-iface.c(1887): device-mapper: reload ioctl on mpatha failed: No such device
...
mpatha: failed to load map, error 19
...
showing also as kernel messages:
device-mapper: table: 252:0: multipath: error attaching hardware handler
device-mapper: ioctl: error adding target to table
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 8930a6c20791 ("scsi: core: add support for request batching")
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/scsi_lib.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 12db0c13a927..5447738906ac 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1922,7 +1922,8 @@ struct scsi_device *scsi_device_from_queue(struct request_queue *q)
{
struct scsi_device *sdev = NULL;
- if (q->mq_ops == &scsi_mq_ops)
+ if (q->mq_ops == &scsi_mq_ops_no_commit ||
+ q->mq_ops == &scsi_mq_ops)
sdev = q->queuedata;
if (!sdev || !get_device(&sdev->sdev_gendev))
sdev = NULL;
--
2.16.4