scsi: scsi_debug: add cmd abort option to every_nth

This patch is motivated by a response in the thread:

  Re: [PATCH 0/5]stop normal completion path entering a timeout req

by Jianchao Wang . It generalizes the error injection of
blk_abort_request() to use scsi_debug's "every_nth" mechanism.  Ref with
original patch to scsi_debug:

https://lore.kernel.org/lkml/a68ad043-26a1-d3d8-2009-504ba4230e0f@oracle.com/

Also convert two vmalloc/memset(0) to vzalloc() calls.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_debug.c

@@ -164,29 +164,29 @@ static const char *sdebug_version_date = "20180128";
 #define SDEBUG_OPT_RESET_NOISE		0x2000
 #define SDEBUG_OPT_NO_CDB_NOISE		0x4000
 #define SDEBUG_OPT_HOST_BUSY		0x8000
+#define SDEBUG_OPT_CMD_ABORT		0x10000
 #define SDEBUG_OPT_ALL_NOISE (SDEBUG_OPT_NOISE | SDEBUG_OPT_Q_NOISE | \
 			      SDEBUG_OPT_RESET_NOISE)
 #define SDEBUG_OPT_ALL_INJECTING (SDEBUG_OPT_RECOVERED_ERR | \
 				  SDEBUG_OPT_TRANSPORT_ERR | \
 				  SDEBUG_OPT_DIF_ERR | SDEBUG_OPT_DIX_ERR | \
 				  SDEBUG_OPT_SHORT_TRANSFER | \
-				  SDEBUG_OPT_HOST_BUSY)
+				  SDEBUG_OPT_HOST_BUSY | \
+				  SDEBUG_OPT_CMD_ABORT)
 /* When "every_nth" > 0 then modulo "every_nth" commands:
  *   - a missing response is simulated if SDEBUG_OPT_TIMEOUT is set
  *   - a RECOVERED_ERROR is simulated on successful read and write
  *     commands if SDEBUG_OPT_RECOVERED_ERR is set.
  *   - a TRANSPORT_ERROR is simulated on successful read and write
  *     commands if SDEBUG_OPT_TRANSPORT_ERR is set.
+ *   - similarly for DIF_ERR, DIX_ERR, SHORT_TRANSFER, HOST_BUSY and
+ *     CMD_ABORT
  *
- * When "every_nth" < 0 then after "- every_nth" commands:
- *   - a missing response is simulated if SDEBUG_OPT_TIMEOUT is set
- *   - a RECOVERED_ERROR is simulated on successful read and write
- *     commands if SDEBUG_OPT_RECOVERED_ERR is set.
- *   - a TRANSPORT_ERROR is simulated on successful read and write
- *     commands if _DEBUG_OPT_TRANSPORT_ERR is set.
- * This will continue on every subsequent command until some other action
- * occurs (e.g. the user * writing a new value (other than -1 or 1) to
- * every_nth via sysfs).
+ * When "every_nth" < 0 then after "- every_nth" commands the selected
+ * error will be injected. The error will be injected on every subsequent
+ * command until some other action occurs; for example, the user writing
+ * a new value (other than -1 or 1) to every_nth:
+ *      echo 0 > /sys/bus/pseudo/drivers/scsi_debug/every_nth
  */
 
 /* As indicated in SAM-5 and SPC-4 Unit Attentions (UAs) are returned in
@@ -281,6 +281,7 @@ struct sdebug_defer {
 	int issuing_cpu;
 	bool init_hrt;
 	bool init_wq;
+	bool aborted;	/* true when blk_abort_request() already called */
 	enum sdeb_defer_type defer_t;
 };
 
@@ -296,6 +297,7 @@ struct sdebug_queued_cmd {
 	unsigned int inj_dix:1;
 	unsigned int inj_short:1;
 	unsigned int inj_host_busy:1;
+	unsigned int inj_cmd_abort:1;
 };
 
 struct sdebug_queue {
@@ -3792,6 +3794,7 @@ static struct sdebug_queue *get_queue(struct scsi_cmnd *cmnd)
 /* Queued (deferred) command completions converge here. */
 static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp)
 {
+	bool aborted = sd_dp->aborted;
 	int qc_idx;
 	int retiring = 0;
 	unsigned long iflags;
@@ -3801,6 +3804,8 @@ static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp)
 	struct sdebug_dev_info *devip;
 
 	sd_dp->defer_t = SDEB_DEFER_NONE;
+	if (unlikely(aborted))
+		sd_dp->aborted = false;
 	qc_idx = sd_dp->qc_idx;
 	sqp = sdebug_q_arr + sd_dp->sqa_idx;
 	if (sdebug_statistics) {
@@ -3852,6 +3857,11 @@ static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp)
 			atomic_set(&retired_max_queue, k + 1);
 	}
 	spin_unlock_irqrestore(&sqp->qc_lock, iflags);
+	if (unlikely(aborted)) {
+		if (sdebug_verbose)
+			pr_info("bypassing scsi_done() due to aborted cmd\n");
+		return;
+	}
 	scp->scsi_done(scp); /* callback to mid level */
 }
 
@@ -4312,7 +4322,8 @@ static void setup_inject(struct sdebug_queue *sqp,
 		if (sdebug_every_nth > 0)
 			sqcp->inj_recovered = sqcp->inj_transport
 				= sqcp->inj_dif
-				= sqcp->inj_dix = sqcp->inj_short = 0;
+				= sqcp->inj_dix = sqcp->inj_short
+				= sqcp->inj_host_busy = sqcp->inj_cmd_abort = 0;
 		return;
 	}
 	sqcp->inj_recovered = !!(SDEBUG_OPT_RECOVERED_ERR & sdebug_opts);
@@ -4321,6 +4332,7 @@ static void setup_inject(struct sdebug_queue *sqp,
 	sqcp->inj_dix = !!(SDEBUG_OPT_DIX_ERR & sdebug_opts);
 	sqcp->inj_short = !!(SDEBUG_OPT_SHORT_TRANSFER & sdebug_opts);
 	sqcp->inj_host_busy = !!(SDEBUG_OPT_HOST_BUSY & sdebug_opts);
+	sqcp->inj_cmd_abort = !!(SDEBUG_OPT_CMD_ABORT & sdebug_opts);
 }
 
 /* Complete the processing of the thread that queued a SCSI command to this
@@ -4458,7 +4470,14 @@ 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;
+		if (unlikely(sqcp->inj_cmd_abort))
+			sd_dp->aborted = true;
 		schedule_work(&sd_dp->ew.work);
+		if (unlikely(sqcp->inj_cmd_abort)) {
+			sdev_printk(KERN_INFO, sdp, "abort request tag %d\n",
+				    cmnd->request->tag);
+			blk_abort_request(cmnd->request);
+		}
 	}
 	if (unlikely((SDEBUG_OPT_Q_NOISE & sdebug_opts) &&
 		     (scsi_result == device_qfull_result)))
@@ -4844,12 +4863,11 @@ static ssize_t fake_rw_store(struct device_driver *ddp, const char *buf,
 					(unsigned long)sdebug_dev_size_mb *
 					1048576;
 
-				fake_storep = vmalloc(sz);
+				fake_storep = vzalloc(sz);
 				if (NULL == fake_storep) {
 					pr_err("out of memory, 9\n");
 					return -ENOMEM;
 				}
-				memset(fake_storep, 0, sz);
 			}
 			sdebug_fake_rw = n;
 		}
@@ -5391,13 +5409,12 @@ static int __init scsi_debug_init(void)
 	}
 
 	if (sdebug_fake_rw == 0) {
-		fake_storep = vmalloc(sz);
+		fake_storep = vzalloc(sz);
 		if (NULL == fake_storep) {
 			pr_err("out of memory, 1\n");
 			ret = -ENOMEM;
 			goto free_q_arr;
 		}
-		memset(fake_storep, 0, sz);
 		if (sdebug_num_parts > 0)
 			sdebug_build_parts(fake_storep, sz);
 	}