scsi_debug: give unit attention and other errors precedence over TSF
Give existing errors priority over the generation of Task
Set Full (TSF) errors. So that max_queue is not exceeded,
existing errors may be sent back in the invocation thread.
This is done so errors like Unit Attentions are not hidden
and lost by either max_queue exceeded or real/injected
TSFs.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 07d224a..693f2fa 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -3006,7 +3006,7 @@
int scsi_result, int delta_jiff)
{
unsigned long iflags;
- int k, num_in_q, tsf, qdepth, inject;
+ int k, num_in_q, qdepth, inject;
struct sdebug_queued_cmd *sqcp = NULL;
struct scsi_device *sdp = cmnd->device;
@@ -3019,55 +3019,48 @@
if ((scsi_result) && (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts))
sdev_printk(KERN_INFO, sdp, "%s: non-zero result=0x%x\n",
__func__, scsi_result);
- if (delta_jiff == 0) {
- /* using same thread to call back mid-layer */
- cmnd->result = scsi_result;
- cmnd->scsi_done(cmnd);
- return 0;
- }
+ if (delta_jiff == 0)
+ goto respond_in_thread;
- /* deferred response cases */
+ /* schedule the response at a later time if resources permit */
spin_lock_irqsave(&queued_arr_lock, iflags);
num_in_q = atomic_read(&devip->num_in_q);
qdepth = cmnd->device->queue_depth;
- k = find_first_zero_bit(queued_in_use_bm, scsi_debug_max_queue);
- tsf = 0;
inject = 0;
- if ((qdepth > 0) && (num_in_q >= qdepth))
- tsf = 1;
- else if ((scsi_debug_every_nth != 0) &&
- (SCSI_DEBUG_OPT_RARE_TSF & scsi_debug_opts)) {
+ if ((qdepth > 0) && (num_in_q >= qdepth)) {
+ if (scsi_result) {
+ spin_unlock_irqrestore(&queued_arr_lock, iflags);
+ goto respond_in_thread;
+ } else
+ scsi_result = device_qfull_result;
+ } else if ((scsi_debug_every_nth != 0) &&
+ (SCSI_DEBUG_OPT_RARE_TSF & scsi_debug_opts) &&
+ (scsi_result == 0)) {
if ((num_in_q == (qdepth - 1)) &&
(atomic_inc_return(&sdebug_a_tsf) >=
abs(scsi_debug_every_nth))) {
atomic_set(&sdebug_a_tsf, 0);
inject = 1;
- tsf = 1;
+ scsi_result = device_qfull_result;
}
}
- /* if (tsf) simulate device reporting SCSI status of TASK SET FULL.
- * Might override existing CHECK CONDITION. */
- if (tsf)
- scsi_result = device_qfull_result;
+ k = find_first_zero_bit(queued_in_use_bm, scsi_debug_max_queue);
if (k >= scsi_debug_max_queue) {
- if (SCSI_DEBUG_OPT_ALL_TSF & scsi_debug_opts)
- tsf = 1;
spin_unlock_irqrestore(&queued_arr_lock, iflags);
+ if (scsi_result)
+ goto respond_in_thread;
+ else if (SCSI_DEBUG_OPT_ALL_TSF & scsi_debug_opts)
+ scsi_result = device_qfull_result;
if (SCSI_DEBUG_OPT_Q_NOISE & scsi_debug_opts)
sdev_printk(KERN_INFO, sdp,
- "%s: num_in_q=%d, bypass q, %s%s\n",
- __func__, num_in_q,
- (inject ? "<inject> " : ""),
- (tsf ? "status: TASK SET FULL" :
- "report: host busy"));
- if (tsf) {
- /* queued_arr full so respond in same thread */
- cmnd->result = scsi_result;
- cmnd->scsi_done(cmnd);
- /* As scsi_done() is called "inline" must return 0 */
- return 0;
- } else
+ "%s: max_queue=%d exceeded, %s\n",
+ __func__, scsi_debug_max_queue,
+ (scsi_result ? "status: TASK SET FULL" :
+ "report: host busy"));
+ if (scsi_result)
+ goto respond_in_thread;
+ else
return SCSI_MLQUEUE_HOST_BUSY;
}
__set_bit(k, queued_in_use_bm);
@@ -3117,12 +3110,18 @@
else
tasklet_schedule(sqcp->tletp);
}
- if (tsf && (SCSI_DEBUG_OPT_Q_NOISE & scsi_debug_opts))
+ if ((SCSI_DEBUG_OPT_Q_NOISE & scsi_debug_opts) &&
+ (scsi_result == device_qfull_result))
sdev_printk(KERN_INFO, sdp,
"%s: num_in_q=%d +1, %s%s\n", __func__,
num_in_q, (inject ? "<inject> " : ""),
"status: TASK SET FULL");
return 0;
+
+respond_in_thread: /* call back to mid-layer using invocation thread */
+ cmnd->result = scsi_result;
+ cmnd->scsi_done(cmnd);
+ return 0;
}
/* Note: The following macros create attribute files in the