[PATCH AUTOSEL 4.19 05/20] scsi: qla2xxx: check UNLOADING before posting async work

[Sasha Levin]

From: Martin Wilck <mwilck@xxxxxxxx>

[ Upstream commit 5a263892d7d0b4fe351363f8d1a14c6a75955475 ]

qlt_free_session_done() tries to post async PRLO / LOGO, and waits for the
completion of these async commands. If UNLOADING is set, this is doomed to
timeout, because the async logout command will never complete.

The only way to avoid waiting pointlessly is to fail posting these commands
in the first place if the driver is in UNLOADING state.  In general,
posting any command should be avoided when the driver is UNLOADING.

With this patch, "rmmod qla2xxx" completes without noticeable delay.

Link: https://lore.kernel.org/r/20200421204621.19228-3-mwilck@xxxxxxxx
Fixes: 45235022da99 ("scsi: qla2xxx: Fix driver unload by shutting down chip")
Acked-by: Arun Easi <aeasi@xxxxxxxxxxx>
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/qla2xxx/qla_os.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index fff20a3707677..d08635203c8a4 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -4647,6 +4647,9 @@ qla2x00_alloc_work(struct scsi_qla_host *vha, enum qla_work_type type)
 	struct qla_work_evt *e;
 	uint8_t bail;
 
+	if (test_bit(UNLOADING, &vha->dpc_flags))
+		return NULL;
+
 	QLA_VHA_MARK_BUSY(vha, bail);
 	if (bail)
 		return NULL;
-- 
2.20.1