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authorDouglas Gilbert <dgilbert@interlog.com>2016-04-25 16:16:32 (GMT)
committerMartin K. Petersen <martin.petersen@oracle.com>2016-04-29 23:27:27 (GMT)
commita10bc12af6347d2aa3a2ffbd5f8b7be260c12b85 (patch)
treed3b1c696994d246c544bee88e0d9163d29242899
parentc2206098972e8ca464040897c95bdf5b2f45ac32 (diff)
downloadlinux-a10bc12af6347d2aa3a2ffbd5f8b7be260c12b85.tar.xz
scsi_debug: replace tasklet with work queue
When a negative value was placed in the delay parameter, a tasklet was scheduled. Change the tasklet to a work queue. Previously a delay of -1 scheduled a high priority tasklet; since there are no high priority work queues, treat -1 like other negative values in delay and schedule a work item. Signed-off-by: Douglas Gilbert <dgilbert@interlog.com> Reviewed-by: Hannes Reinicke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/scsi_debug.c230
1 files changed, 95 insertions, 135 deletions
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index e2fbac3..40de305 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -610,15 +610,15 @@ static LIST_HEAD(sdebug_host_list);
static DEFINE_SPINLOCK(sdebug_host_list_lock);
-struct sdebug_hrtimer { /* ... is derived from hrtimer */
- struct hrtimer hrt; /* must be first element */
+struct sdebug_defer {
+ struct hrtimer hrt;
+ struct execute_work ew;
int qa_indx;
};
struct sdebug_queued_cmd {
/* in_use flagged by a bit in queued_in_use_bm[] */
- struct tasklet_struct *tletp;
- struct sdebug_hrtimer *sd_hrtp;
+ struct sdebug_defer *sd_dp;
struct scsi_cmnd * a_cmnd;
};
static struct sdebug_queued_cmd queued_arr[SCSI_DEBUG_CANQUEUE];
@@ -3349,8 +3349,9 @@ resp_xdwriteread_10(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
return resp_xdwriteread(scp, lba, num, devip);
}
-/* When tasklet goes off this function is called. */
-static void sdebug_q_cmd_complete(unsigned long indx)
+/* Queued command completions converge here. */
+static void
+sdebug_q_cmd_complete(struct sdebug_defer *sd_dp)
{
int qa_indx;
int retiring = 0;
@@ -3360,7 +3361,7 @@ static void sdebug_q_cmd_complete(unsigned long indx)
struct sdebug_dev_info *devip;
atomic_inc(&sdebug_completions);
- qa_indx = indx;
+ qa_indx = sd_dp->qa_indx;
if ((qa_indx < 0) || (qa_indx >= SCSI_DEBUG_CANQUEUE)) {
pr_err("wild qa_indx=%d\n", qa_indx);
return;
@@ -3411,64 +3412,21 @@ static void sdebug_q_cmd_complete(unsigned long indx)
static enum hrtimer_restart
sdebug_q_cmd_hrt_complete(struct hrtimer *timer)
{
- int qa_indx;
- int retiring = 0;
- unsigned long iflags;
- struct sdebug_hrtimer *sd_hrtp = (struct sdebug_hrtimer *)timer;
- struct sdebug_queued_cmd *sqcp;
- struct scsi_cmnd *scp;
- struct sdebug_dev_info *devip;
-
- atomic_inc(&sdebug_completions);
- qa_indx = sd_hrtp->qa_indx;
- if ((qa_indx < 0) || (qa_indx >= SCSI_DEBUG_CANQUEUE)) {
- pr_err("wild qa_indx=%d\n", qa_indx);
- goto the_end;
- }
- spin_lock_irqsave(&queued_arr_lock, iflags);
- sqcp = &queued_arr[qa_indx];
- scp = sqcp->a_cmnd;
- if (NULL == scp) {
- spin_unlock_irqrestore(&queued_arr_lock, iflags);
- pr_err("scp is NULL\n");
- goto the_end;
- }
- devip = (struct sdebug_dev_info *)scp->device->hostdata;
- if (devip)
- atomic_dec(&devip->num_in_q);
- else
- pr_err("devip=NULL\n");
- if (atomic_read(&retired_max_queue) > 0)
- retiring = 1;
-
- sqcp->a_cmnd = NULL;
- if (!test_and_clear_bit(qa_indx, queued_in_use_bm)) {
- spin_unlock_irqrestore(&queued_arr_lock, iflags);
- pr_err("Unexpected completion\n");
- goto the_end;
- }
-
- if (unlikely(retiring)) { /* user has reduced max_queue */
- int k, retval;
-
- retval = atomic_read(&retired_max_queue);
- if (qa_indx >= retval) {
- spin_unlock_irqrestore(&queued_arr_lock, iflags);
- pr_err("index %d too large\n", retval);
- goto the_end;
- }
- k = find_last_bit(queued_in_use_bm, retval);
- if ((k < sdebug_max_queue) || (k == retval))
- atomic_set(&retired_max_queue, 0);
- else
- atomic_set(&retired_max_queue, k + 1);
- }
- spin_unlock_irqrestore(&queued_arr_lock, iflags);
- scp->scsi_done(scp); /* callback to mid level */
-the_end:
+ struct sdebug_defer *sd_dp = container_of(timer, struct sdebug_defer,
+ hrt);
+ sdebug_q_cmd_complete(sd_dp);
return HRTIMER_NORESTART;
}
+/* When work queue schedules work, it calls this function. */
+static void
+sdebug_q_cmd_wq_complete(struct work_struct *work)
+{
+ struct sdebug_defer *sd_dp = container_of(work, struct sdebug_defer,
+ ew.work);
+ sdebug_q_cmd_complete(sd_dp);
+}
+
static struct sdebug_dev_info *
sdebug_device_create(struct sdebug_host_info *sdbg_host, gfp_t flags)
{
@@ -3567,13 +3525,15 @@ static void scsi_debug_slave_destroy(struct scsi_device *sdp)
}
}
-/* Returns 1 if cmnd found (deletes its timer or tasklet), else returns 0 */
-static int stop_queued_cmnd(struct scsi_cmnd *cmnd)
+/* If @cmnd found deletes its timer or work queue and returns true; else
+ returns false */
+static bool stop_queued_cmnd(struct scsi_cmnd *cmnd)
{
unsigned long iflags;
int k, qmax, r_qmax;
struct sdebug_queued_cmd *sqcp;
struct sdebug_dev_info *devip;
+ struct sdebug_defer *sd_dp;
spin_lock_irqsave(&queued_arr_lock, iflags);
qmax = sdebug_max_queue;
@@ -3583,64 +3543,63 @@ static int stop_queued_cmnd(struct scsi_cmnd *cmnd)
for (k = 0; k < qmax; ++k) {
if (test_bit(k, queued_in_use_bm)) {
sqcp = &queued_arr[k];
- if (cmnd == sqcp->a_cmnd) {
- devip = (struct sdebug_dev_info *)
- cmnd->device->hostdata;
- if (devip)
- atomic_dec(&devip->num_in_q);
- sqcp->a_cmnd = NULL;
- spin_unlock_irqrestore(&queued_arr_lock,
- iflags);
- if ((sdebug_jdelay > 0) ||
- (sdebug_ndelay > 0)) {
- if (sqcp->sd_hrtp)
- hrtimer_cancel(
- &sqcp->sd_hrtp->hrt);
- } else if (sdebug_jdelay < 0) {
- if (sqcp->tletp)
- tasklet_kill(sqcp->tletp);
- }
- clear_bit(k, queued_in_use_bm);
- return 1;
+ if (cmnd != sqcp->a_cmnd)
+ continue;
+ /* found command */
+ devip = (struct sdebug_dev_info *)
+ cmnd->device->hostdata;
+ if (devip)
+ atomic_dec(&devip->num_in_q);
+ sqcp->a_cmnd = NULL;
+ sd_dp = sqcp->sd_dp;
+ spin_unlock_irqrestore(&queued_arr_lock,
+ iflags);
+ if ((sdebug_jdelay > 0) || (sdebug_ndelay > 0)) {
+ if (sd_dp)
+ hrtimer_cancel(&sd_dp->hrt);
+ } else if (sdebug_jdelay < 0) {
+ if (sd_dp)
+ cancel_work_sync(&sd_dp->ew.work);
}
+ clear_bit(k, queued_in_use_bm);
+ return true;
}
}
spin_unlock_irqrestore(&queued_arr_lock, iflags);
- return 0;
+ return false;
}
-/* Deletes (stops) timers or tasklets of all queued commands */
+/* Deletes (stops) timers or work queues of all queued commands */
static void stop_all_queued(void)
{
unsigned long iflags;
int k;
struct sdebug_queued_cmd *sqcp;
struct sdebug_dev_info *devip;
+ struct sdebug_defer *sd_dp;
spin_lock_irqsave(&queued_arr_lock, iflags);
for (k = 0; k < SCSI_DEBUG_CANQUEUE; ++k) {
if (test_bit(k, queued_in_use_bm)) {
sqcp = &queued_arr[k];
- if (sqcp->a_cmnd) {
- devip = (struct sdebug_dev_info *)
- sqcp->a_cmnd->device->hostdata;
- if (devip)
- atomic_dec(&devip->num_in_q);
- sqcp->a_cmnd = NULL;
- spin_unlock_irqrestore(&queued_arr_lock,
- iflags);
- if ((sdebug_jdelay > 0) ||
- (sdebug_ndelay > 0)) {
- if (sqcp->sd_hrtp)
- hrtimer_cancel(
- &sqcp->sd_hrtp->hrt);
- } else if (sdebug_jdelay < 0) {
- if (sqcp->tletp)
- tasklet_kill(sqcp->tletp);
- }
- clear_bit(k, queued_in_use_bm);
- spin_lock_irqsave(&queued_arr_lock, iflags);
+ if (NULL == sqcp->a_cmnd)
+ continue;
+ devip = (struct sdebug_dev_info *)
+ sqcp->a_cmnd->device->hostdata;
+ if (devip)
+ atomic_dec(&devip->num_in_q);
+ sqcp->a_cmnd = NULL;
+ sd_dp = sqcp->sd_dp;
+ spin_unlock_irqrestore(&queued_arr_lock, iflags);
+ if ((sdebug_jdelay > 0) || (sdebug_ndelay > 0)) {
+ if (sd_dp)
+ hrtimer_cancel(&sd_dp->hrt);
+ } else if (sdebug_jdelay < 0) {
+ if (sd_dp)
+ cancel_work_sync(&sd_dp->ew.work);
}
+ clear_bit(k, queued_in_use_bm);
+ spin_lock_irqsave(&queued_arr_lock, iflags);
}
}
spin_unlock_irqrestore(&queued_arr_lock, iflags);
@@ -3649,30 +3608,27 @@ static void stop_all_queued(void)
/* Free queued command memory on heap */
static void free_all_queued(void)
{
- unsigned long iflags;
int k;
struct sdebug_queued_cmd *sqcp;
- spin_lock_irqsave(&queued_arr_lock, iflags);
for (k = 0; k < SCSI_DEBUG_CANQUEUE; ++k) {
sqcp = &queued_arr[k];
- kfree(sqcp->tletp);
- sqcp->tletp = NULL;
- kfree(sqcp->sd_hrtp);
- sqcp->sd_hrtp = NULL;
+ kfree(sqcp->sd_dp);
+ sqcp->sd_dp = NULL;
}
- spin_unlock_irqrestore(&queued_arr_lock, iflags);
}
static int scsi_debug_abort(struct scsi_cmnd *SCpnt)
{
+ bool ok;
+
++num_aborts;
if (SCpnt) {
- if (SCpnt->device &&
- (SDEBUG_OPT_ALL_NOISE & sdebug_opts))
- sdev_printk(KERN_INFO, SCpnt->device, "%s\n",
- __func__);
- stop_queued_cmnd(SCpnt);
+ ok = stop_queued_cmnd(SCpnt);
+ if (SCpnt->device && (SDEBUG_OPT_ALL_NOISE & sdebug_opts))
+ sdev_printk(KERN_INFO, SCpnt->device,
+ "%s: command%s found\n", __func__,
+ ok ? "" : " not");
}
return SUCCESS;
}
@@ -3846,6 +3802,7 @@ schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
int k, num_in_q, qdepth, inject;
struct sdebug_queued_cmd *sqcp = NULL;
struct scsi_device *sdp;
+ struct sdebug_defer *sd_dp;
/* this should never happen */
if (WARN_ON(!cmnd))
@@ -3912,8 +3869,8 @@ schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
sqcp->a_cmnd = cmnd;
cmnd->result = scsi_result;
spin_unlock_irqrestore(&queued_arr_lock, iflags);
+ sd_dp = sqcp->sd_dp;
if ((delta_jiff > 0) || (sdebug_ndelay > 0)) {
- struct sdebug_hrtimer *sd_hp = sqcp->sd_hrtp;
ktime_t kt;
if (delta_jiff > 0) {
@@ -3923,30 +3880,27 @@ schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
kt = ktime_set(ts.tv_sec, ts.tv_nsec);
} else
kt = ktime_set(0, sdebug_ndelay);
- if (NULL == sd_hp) {
- sd_hp = kzalloc(sizeof(*sd_hp), GFP_ATOMIC);
- if (NULL == sd_hp)
+ if (NULL == sd_dp) {
+ sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC);
+ if (NULL == sd_dp)
return SCSI_MLQUEUE_HOST_BUSY;
- sqcp->sd_hrtp = sd_hp;
- hrtimer_init(&sd_hp->hrt, CLOCK_MONOTONIC,
+ sqcp->sd_dp = sd_dp;
+ hrtimer_init(&sd_dp->hrt, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
- sd_hp->hrt.function = sdebug_q_cmd_hrt_complete;
- sd_hp->qa_indx = k;
+ sd_dp->hrt.function = sdebug_q_cmd_hrt_complete;
+ sd_dp->qa_indx = k;
}
- hrtimer_start(&sd_hp->hrt, kt, HRTIMER_MODE_REL);
+ hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL);
} else { /* jdelay < 0 */
- if (NULL == sqcp->tletp) {
- sqcp->tletp = kzalloc(sizeof(*sqcp->tletp),
- GFP_ATOMIC);
- if (NULL == sqcp->tletp)
+ if (NULL == sd_dp) {
+ sd_dp = kzalloc(sizeof(*sqcp->sd_dp), GFP_ATOMIC);
+ if (NULL == sd_dp)
return SCSI_MLQUEUE_HOST_BUSY;
- tasklet_init(sqcp->tletp,
- sdebug_q_cmd_complete, k);
+ sqcp->sd_dp = sd_dp;
+ sd_dp->qa_indx = k;
+ INIT_WORK(&sd_dp->ew.work, sdebug_q_cmd_wq_complete);
}
- if (-1 == delta_jiff)
- tasklet_hi_schedule(sqcp->tletp);
- else
- tasklet_schedule(sqcp->tletp);
+ schedule_work(&sd_dp->ew.work);
}
if ((SDEBUG_OPT_Q_NOISE & sdebug_opts) &&
(scsi_result == device_qfull_result))
@@ -4149,6 +4103,9 @@ static ssize_t delay_store(struct device_driver *ddp, const char *buf,
if (k != sdebug_max_queue)
res = -EBUSY; /* have queued commands */
else {
+ /* make sure sdebug_defer instances get
+ * re-allocated for new delay variant */
+ free_all_queued();
sdebug_jdelay = jdelay;
sdebug_ndelay = 0;
}
@@ -4181,6 +4138,9 @@ static ssize_t ndelay_store(struct device_driver *ddp, const char *buf,
if (k != sdebug_max_queue)
res = -EBUSY; /* have queued commands */
else {
+ /* 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;