[PATCH 6/6] scsi: Implement blk_mq_ops.show_rq()

Bart Van Assche
2017-04-11T20:58:42Z

Show the SCSI CDB, .eh_eflags and .result for pending SCSI commands
in /sys/kernel/debug/block/*/mq/*/dispatch and */rq_list.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: <linux-scsi@vger.kernel.org>
---
drivers/scsi/scsi_lib.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7bc4513bf4e4..7d3efb8924ee 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2126,6 +2126,32 @@ static void scsi_exit_rq(struct request_queue *q, struct request *rq)
scsi_free_sense_buffer(shost, cmd->sense_buffer);
}

+static const char *const ehflag_name[] = {
+ [ilog2(SCSI_EH_CANCEL_CMD)] = "CANCEL_CMD",
+ [ilog2(SCSI_EH_ABORT_SCHEDULED)] = "ABORT_SCHEDULED",
+};
+
+static void scsi_show_rq(struct request *rq, char *info, unsigned int info_sz)
+{
+ char *p = info, *const end = info + info_sz;
+ struct scsi_cmnd *cmd = container_of(scsi_req(rq), typeof(*cmd), req);
+ unsigned int i;
+
+ p += scnprintf(p, end - p, ".cmd =");
+ for (i = 0; i < cmd->cmd_len; i++)
+ p += scnprintf(p, end - p, " %02x", cmd->cmnd[i]);
+ p += scnprintf(p, end - p, ", .eh_eflags =");
+ for (i = 0; i < sizeof(cmd->eh_eflags) * BITS_PER_BYTE; i++) {
+ if (!(cmd->eh_eflags & BIT(i)))
+ continue;
+ if (i < ARRAY_SIZE(ehflag_name) && ehflag_name[i])
+ p += scnprintf(p, end - p, " %s", ehflag_name[i]);
+ else
+ p += scnprintf(p, end - p, " %d", i);
+ }
+ p += scnprintf(p, end - p, ", .result = %#06x", cmd->result);
+}
+
struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
{
struct Scsi_Host *shost = sdev->host;
@@ -2158,6 +2184,7 @@ static const struct blk_mq_ops scsi_mq_ops = {
.queue_rq = scsi_queue_rq,
.complete = scsi_softirq_done,
.timeout = scsi_timeout,
+ .show_rq = scsi_show_rq,
.init_request = scsi_init_request,
.exit_request = scsi_exit_request,
.map_queues = scsi_map_queues,
--
2.12.0