scsi: qla2xxx: Fix the call trace for flush workqueue

The call trace was because workqueue was allocated without any flags, added
WQ_MEM_RECLAIM as flag when allocating.

kernel: workqueue: WQ_MEM_RECLAIM
kblockd:blk_mq_run_work_fn is flushing !WQ_MEM_RECLAIM qla2xxx_wq:0x0
kernel: WARNING: CPU: 0 PID: 2475 at
kernel/workqueue.c:2593 check_flush_dependency+0x110/0x130
kernel: CPU: 0 PID: 2475 Comm: kworker/0:1H Kdump:
loaded Tainted: G           OE    --------- -  - 4.18.0-193.el8.x86_64 #1
kernel: Hardware name: HPE ProLiant XL170r Gen10/ProLiant XL170r Gen10, BIOS U38 05/21/2019
kernel: Workqueue: kblockd blk_mq_run_work_fn
kernel: RIP: 0010:check_flush_dependency+0x110/0x130
kernel: Code: ff ff 48 8b 50 18 48 8d 8b b0 00 00 00 49 89 e8 48 81 c6 b0 00 00 00 48 c7 c7 00 1e e9
	95 c6 05 dc 9a 2f 01 01 e8 1a 42 fe ff <0f> 0b e9 0a ff ff ff 80 3d ca 9a 2f 01 0 0 75 95 e9 41 ff ff ff 90
kernel: RSP: 0018:ffffa40f48b2baf8 EFLAGS: 00010282
kernel: RAX: 0000000000000000 RBX: ffff946795282600 RCX: 0000000000000000
kernel: RDX: 000000000000005f RSI: ffffffff96a1af7f RDI: 0000000000000246
kernel: RBP: 0000000000000000 R08: ffffffff96a1af20 R09: 0000000000029480
kernel: R10: 00080c89bb3e7462 R11: 00000000000009ab R12: ffff946773628000
kernel: R13: 0000000000000282 R14: 0000000000000246 R15: ffffa40f48b2bb40
kernel: FS: 	0000000000000000(0000) 	GS:ffff94679fa00000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00005570c4b60110 CR3: 000000029140a005 CR4: 00000000007606f0
kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kernel: PKRU: 55555554
kernel: Call Trace:
kernel: flush_workqueue+0x13a/0x440
kernel: qla2x00_wait_for_sess_deletion+0x1d6/0x200 [qla2xxx]
kernel: ? finish_wait+0x80/0x80
kernel: qla2xxx_disable_port+0x2b/0x30 [qla2xxx]
kernel: qla2x00_process_vendor_specific+0x1dc9/0x2d20 [qla2xxx]
kernel: ? blk_rq_map_sg+0x195/0x570
kernel: qla24xx_bsg_request+0x1a3/0xf90 [qla2xxx]

Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Himanshu Madhani <[email protected]>
Signed-off-by: Saurav Kashyap <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

drivers/scsi/qla2xxx/qla_os.c

@@ -3265,7 +3265,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	    "req->req_q_in=%p req->req_q_out=%p rsp->rsp_q_in=%p rsp->rsp_q_out=%p.\n",
 	    req->req_q_in, req->req_q_out, rsp->rsp_q_in, rsp->rsp_q_out);
 
-	ha->wq = alloc_workqueue("qla2xxx_wq", 0, 0);
+	ha->wq = alloc_workqueue("qla2xxx_wq", WQ_MEM_RECLAIM, 0);
 	if (unlikely(!ha->wq)) {
 		ret = -ENOMEM;
 		goto probe_failed;