When the internal in_use bit array in this driver is full returning SCSI_MLQUEUE_HOST_BUSY leads to the mid-level re-issueing 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. Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> --- drivers/scsi/scsi_debug.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 3fb9e0072627..6d50d248ff3a 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -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; + 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) - goto respond_in_thread; - else - return SCSI_MLQUEUE_HOST_BUSY; + sdev_printk(KERN_INFO, sdp, "%s: max_queue=%d exceeded: TASK SET FULL\n", + __func__, sdebug_max_queue); + goto respond_in_thread; } set_bit(k, sqp->in_use_bm); atomic_inc(&devip->num_in_q); -- 2.25.1
