Commit 10bde980 authored by Douglas Gilbert's avatar Douglas Gilbert Committed by Martin K. Petersen
Browse files

scsi: scsi_debug: delay stress fix 



Introduce a state enum into sdebug_defer objects to indicate which, if
any, defer method has been used with the associated command.  Also add 2
bools to indicate which of the defer methods has been initialized. Those
objects are re-used but the initialization only needs to be done
once. This simplifies command cancellation handling.

Now the delay associated with a deferred response of a command cannot be
changed (once started) by changing the delay (and ndelay) parameters in
sysfs. Command aborts and driver shutdown are still honoured immediately
when received.

[mkp: applied by hand]

Signed-off-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent dbc1ebe7

drivers/scsi/scsi_debug.c

+46 −26
Original line number Diff line number Diff line
@@ -267,12 +267,18 @@ struct sdebug_host_info { 
#define to_sdebug_host(d)	\

	container_of(d, struct sdebug_host_info, dev)



enum sdeb_defer_type {SDEB_DEFER_NONE = 0, SDEB_DEFER_HRT = 1,

		      SDEB_DEFER_WQ = 2};



struct sdebug_defer {

	struct hrtimer hrt;

	struct execute_work ew;

	int sqa_idx;	/* index of sdebug_queue array */

	int qc_idx;	/* index of sdebug_queued_cmd array within sqa_idx */

	int issuing_cpu;

	bool init_hrt;

	bool init_wq;

	enum sdeb_defer_type defer_t;

};



struct sdebug_queued_cmd {
@@ -3748,6 +3754,7 @@ static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp) 
	struct scsi_cmnd *scp;

	struct sdebug_dev_info *devip;



	sd_dp->defer_t = SDEB_DEFER_NONE;

	qc_idx = sd_dp->qc_idx;

	sqp = sdebug_q_arr + sd_dp->sqa_idx;

	if (sdebug_statistics) {
@@ -3932,13 +3939,14 @@ static void scsi_debug_slave_destroy(struct scsi_device *sdp) 
	}

}



static void stop_qc_helper(struct sdebug_defer *sd_dp)

static void stop_qc_helper(struct sdebug_defer *sd_dp,

			   enum sdeb_defer_type defer_t)

{

	if (!sd_dp)

		return;

	if ((sdebug_jdelay > 0) || (sdebug_ndelay > 0))

	if (defer_t == SDEB_DEFER_HRT)

		hrtimer_cancel(&sd_dp->hrt);

	else if (sdebug_jdelay < 0)

	else if (defer_t == SDEB_DEFER_WQ)

		cancel_work_sync(&sd_dp->ew.work);

}
@@ -3948,6 +3956,7 @@ static bool stop_queued_cmnd(struct scsi_cmnd *cmnd) 
{

	unsigned long iflags;

	int j, k, qmax, r_qmax;

	enum sdeb_defer_type l_defer_t;

	struct sdebug_queue *sqp;

	struct sdebug_queued_cmd *sqcp;

	struct sdebug_dev_info *devip;
@@ -3971,8 +3980,13 @@ static bool stop_queued_cmnd(struct scsi_cmnd *cmnd) 
					atomic_dec(&devip->num_in_q);

				sqcp->a_cmnd = NULL;

				sd_dp = sqcp->sd_dp;

				if (sd_dp) {

					l_defer_t = sd_dp->defer_t;

					sd_dp->defer_t = SDEB_DEFER_NONE;

				} else

					l_defer_t = SDEB_DEFER_NONE;

				spin_unlock_irqrestore(&sqp->qc_lock, iflags);

				stop_qc_helper(sd_dp);

				stop_qc_helper(sd_dp, l_defer_t);

				clear_bit(k, sqp->in_use_bm);

				return true;

			}
@@ -3987,6 +4001,7 @@ static void stop_all_queued(void) 
{

	unsigned long iflags;

	int j, k;

	enum sdeb_defer_type l_defer_t;

	struct sdebug_queue *sqp;

	struct sdebug_queued_cmd *sqcp;

	struct sdebug_dev_info *devip;
@@ -4005,8 +4020,13 @@ static void stop_all_queued(void) 
					atomic_dec(&devip->num_in_q);

				sqcp->a_cmnd = NULL;

				sd_dp = sqcp->sd_dp;

				if (sd_dp) {

					l_defer_t = sd_dp->defer_t;

					sd_dp->defer_t = SDEB_DEFER_NONE;

				} else

					l_defer_t = SDEB_DEFER_NONE;

				spin_unlock_irqrestore(&sqp->qc_lock, iflags);

				stop_qc_helper(sd_dp);

				stop_qc_helper(sd_dp, l_defer_t);

				clear_bit(k, sqp->in_use_bm);

				spin_lock_irqsave(&sqp->qc_lock, iflags);

			}
@@ -4258,7 +4278,7 @@ static void setup_inject(struct sdebug_queue *sqp, 
 * SCSI_MLQUEUE_HOST_BUSY if temporarily out of resources.

 */

static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,

			 int scsi_result, int delta_jiff)

			 int scsi_result, int delta_jiff, int ndelay)

{

	unsigned long iflags;

	int k, num_in_q, qdepth, inject;
@@ -4336,17 +4356,20 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
	spin_unlock_irqrestore(&sqp->qc_lock, iflags);

	if (unlikely(sdebug_every_nth && sdebug_any_injecting_opt))

		setup_inject(sqp, sqcp);

	if (delta_jiff > 0 || sdebug_ndelay > 0) {

	if (sd_dp == NULL) {

		sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC);

		if (sd_dp == NULL)

			return SCSI_MLQUEUE_HOST_BUSY;

	}

	if (delta_jiff > 0 || ndelay > 0) {

		ktime_t kt;



		if (delta_jiff > 0) {

			kt = ns_to_ktime((u64)delta_jiff * (NSEC_PER_SEC / HZ));

		} else

			kt = sdebug_ndelay;

		if (NULL == sd_dp) {

			sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC);

			if (NULL == sd_dp)

				return SCSI_MLQUEUE_HOST_BUSY;

			kt = ndelay;

		if (!sd_dp->init_hrt) {

			sd_dp->init_hrt = true;

			sqcp->sd_dp = sd_dp;

			hrtimer_init(&sd_dp->hrt, CLOCK_MONOTONIC,

				     HRTIMER_MODE_REL_PINNED);
@@ -4356,12 +4379,11 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
		}

		if (sdebug_statistics)

			sd_dp->issuing_cpu = raw_smp_processor_id();

		sd_dp->defer_t = SDEB_DEFER_HRT;

		hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED);

	} else {	/* jdelay < 0, use work queue */

		if (NULL == sd_dp) {

			sd_dp = kzalloc(sizeof(*sqcp->sd_dp), GFP_ATOMIC);

			if (NULL == sd_dp)

				return SCSI_MLQUEUE_HOST_BUSY;

		if (!sd_dp->init_wq) {

			sd_dp->init_wq = true;

			sqcp->sd_dp = sd_dp;

			sd_dp->sqa_idx = sqp - sdebug_q_arr;

			sd_dp->qc_idx = k;
@@ -4369,6 +4391,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
		}

		if (sdebug_statistics)

			sd_dp->issuing_cpu = raw_smp_processor_id();

		sd_dp->defer_t = SDEB_DEFER_WQ;

		schedule_work(&sd_dp->ew.work);

	}

	if (unlikely((SDEBUG_OPT_Q_NOISE & sdebug_opts) &&
@@ -4615,9 +4638,6 @@ static ssize_t delay_store(struct device_driver *ddp, const char *buf, 
				}

			}

			if (res > 0) {

				/* make sure sdebug_defer instances get

				 * re-allocated for new delay variant */

				free_all_queued();

				sdebug_jdelay = jdelay;

				sdebug_ndelay = 0;

			}
@@ -4658,9 +4678,6 @@ static ssize_t ndelay_store(struct device_driver *ddp, const char *buf, 
				}

			}

			if (res > 0) {

				/* make sure sdebug_defer instances get

				 * re-allocated for new delay variant */

				free_all_queued();

				sdebug_ndelay = ndelay;

				sdebug_jdelay = ndelay  ? JDELAY_OVERRIDDEN

							: DEF_JDELAY;
@@ -5702,12 +5719,15 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost, 
		errsts = r_pfp(scp, devip);



fini:

	return schedule_resp(scp, devip, errsts,

			     ((F_DELAY_OVERR & flags) ? 0 : sdebug_jdelay));

	if (F_DELAY_OVERR & flags)

		return schedule_resp(scp, devip, errsts, 0, 0);

	else

		return schedule_resp(scp, devip, errsts, sdebug_jdelay,

				     sdebug_ndelay);

check_cond:

	return schedule_resp(scp, devip, check_condition_result, 0);

	return schedule_resp(scp, devip, check_condition_result, 0, 0);

err_out:

	return schedule_resp(scp, NULL, DID_NO_CONNECT << 16, 0);

	return schedule_resp(scp, NULL, DID_NO_CONNECT << 16, 0, 0);

}



static struct scsi_host_template sdebug_driver_template = {

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