Commit 7d5a129b authored by Douglas Gilbert's avatar Douglas Gilbert Committed by Martin K. Petersen
Browse files

scsi: scsi_debug: Use TASK SET FULL more 

When the internal in_use bit array in this driver is full returning
SCSI_MLQUEUE_HOST_BUSY leads to the mid-level reissuing the request which
is unhelpful. Previously TASK SET FULL status was only returned if ALL_TSF
[0x400] is placed in the opts variable (at load time or via sysfs). Now
ignore that setting and always return TASK SET FULL when in_use array is
full. Also set DID_ABORT together with TASK SET FULL so the mid-level gives
up immediately.

Aside: the situations addressed by this patch lead to lockups and
timeouts. They have only been detected when blk_poll() is used. That
mechanism is relatively new in the SCSI subsystem suggesting the mid-level
may need more work in that area.

Link: https://lore.kernel.org/r/20220109012853.301953-4-dgilbert@interlog.com


Signed-off-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d9d23a5a

drivers/scsi/scsi_debug.c

+6 −13
Original line number Diff line number Diff line
@@ -174,7 +174,7 @@ static const char *sdebug_version_date = "20200710"; 
#define SDEBUG_OPT_MAC_TIMEOUT		128

#define SDEBUG_OPT_SHORT_TRANSFER	0x100

#define SDEBUG_OPT_Q_NOISE		0x200

#define SDEBUG_OPT_ALL_TSF		0x400

#define SDEBUG_OPT_ALL_TSF		0x400	/* ignore */

#define SDEBUG_OPT_RARE_TSF		0x800

#define SDEBUG_OPT_N_WCE		0x1000

#define SDEBUG_OPT_RESET_NOISE		0x2000
@@ -861,7 +861,7 @@ static const int illegal_condition_result = 
	(DID_ABORT << 16) | SAM_STAT_CHECK_CONDITION;



static const int device_qfull_result =

	(DID_OK << 16) | SAM_STAT_TASK_SET_FULL;

	(DID_ABORT << 16) | SAM_STAT_TASK_SET_FULL;



static const int condition_met_result = SAM_STAT_CONDITION_MET;
@@ -5521,18 +5521,11 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
		spin_unlock_irqrestore(&sqp->qc_lock, iflags);

		if (scsi_result)

			goto respond_in_thread;

		else if (SDEBUG_OPT_ALL_TSF & sdebug_opts)

		scsi_result = device_qfull_result;

		if (SDEBUG_OPT_Q_NOISE & sdebug_opts)

			sdev_printk(KERN_INFO, sdp,

				    "%s: max_queue=%d exceeded, %s\n",

				    __func__, sdebug_max_queue,

				    (scsi_result ?  "status: TASK SET FULL" :

						    "report: host busy"));

		if (scsi_result)

			sdev_printk(KERN_INFO, sdp, "%s: max_queue=%d exceeded: TASK SET FULL\n",

				    __func__, sdebug_max_queue);

		goto respond_in_thread;

		else

			return SCSI_MLQUEUE_HOST_BUSY;

	}

	set_bit(k, sqp->in_use_bm);

	atomic_inc(&devip->num_in_q);