scsi: scsi_debug: Add support for injecting SCSI_MLQUEUE_HOST_BUSY

Although it is important to be able to trigger the code in the SCSI core
for SCSI_MLQUEUE_HOST_BUSY handling, currently it is nontrivial to
trigger that code. Hence this patch that adds a new error injection
option to the scsi_debug driver for making the .queue_rq()
implementation of this driver return SCSI_MLQUEUE_HOST_BUSY.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bart Van Assche 2017-12-07 14:56:18 -08:00 committed by Martin K. Petersen
parent 0b7509c76d
commit 7ee6d1b435
1 changed files with 13 additions and 1 deletions

View File

@ -162,12 +162,14 @@ static const char *sdebug_version_date = "20171202";
#define SDEBUG_OPT_N_WCE 0x1000
#define SDEBUG_OPT_RESET_NOISE 0x2000
#define SDEBUG_OPT_NO_CDB_NOISE 0x4000
#define SDEBUG_OPT_HOST_BUSY 0x8000
#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_SHORT_TRANSFER | \
SDEBUG_OPT_HOST_BUSY)
/* 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
@ -283,6 +285,7 @@ struct sdebug_queued_cmd {
unsigned int inj_dif:1;
unsigned int inj_dix:1;
unsigned int inj_short:1;
unsigned int inj_host_busy:1;
};
struct sdebug_queue {
@ -4055,6 +4058,7 @@ static void setup_inject(struct sdebug_queue *sqp,
sqcp->inj_dif = !!(SDEBUG_OPT_DIF_ERR & sdebug_opts);
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);
}
/* Complete the processing of the thread that queued a SCSI command to this
@ -5360,6 +5364,12 @@ static bool fake_timeout(struct scsi_cmnd *scp)
return false;
}
static bool fake_host_busy(struct scsi_cmnd *scp)
{
return (sdebug_opts & SDEBUG_OPT_HOST_BUSY) &&
(atomic_read(&sdebug_cmnd_count) % abs(sdebug_every_nth)) == 0;
}
static int scsi_debug_queuecommand(struct Scsi_Host *shost,
struct scsi_cmnd *scp)
{
@ -5402,6 +5412,8 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost,
sdev_printk(KERN_INFO, sdp, "%s: cmd %s\n", my_name,
b);
}
if (fake_host_busy(scp))
return SCSI_MLQUEUE_HOST_BUSY;
has_wlun_rl = (sdp->lun == SCSI_W_LUN_REPORT_LUNS);
if (unlikely((sdp->lun >= sdebug_max_luns) && !has_wlun_rl))
goto err_out;