Show the request result, request timeout and SCSI command flags.
This information is very helpful when trying to figure out why a
queue got stuck. An example of the information that is exported
through debugfs:
$ (cd /sys/kernel/debug/block && find -type f -print0 | xargs -0 grep ago)
./sda/hctx0/busy:ffff8804a4523300 {.op=READ, .cmd_flags=FAILFAST_DEV|FAILFAST_TRANSPORT|FAILFAST_DRIVER|RAHEAD, .rq_flags=MQ_INFLIGHT|DONTPREP|IO_STAT|STATS, .atomic_flags=STARTED, .tag=24, .internal_tag=-1, .cmd=Read(10) 28 00 06 80 1c c8 00 00 08 00, .retries=0, .result = 0x0, .flags=TAGGED|INITIALIZED, .timeout=90.000, allocated 0.010 s ago}
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: James E.J. Bottomley <jejb@xxxxxxxxxxxxxxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
drivers/scsi/scsi_debugfs.c | 41 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 38 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_debugfs.c b/drivers/scsi/scsi_debugfs.c
index c3765d29fd3f..37ed6bb8e6ec 100644
--- a/drivers/scsi/scsi_debugfs.c
+++ b/drivers/scsi/scsi_debugfs.c
@@ -4,15 +4,50 @@
#include <scsi/scsi_dbg.h>
#include "scsi_debugfs.h"
+#define SCSI_CMD_FLAG_NAME(name) [ilog2(SCMD_##name)] = #name
+static const char *const scsi_cmd_flags[] = {
+ SCSI_CMD_FLAG_NAME(TAGGED),
+ SCSI_CMD_FLAG_NAME(UNCHECKED_ISA_DMA),
+ SCSI_CMD_FLAG_NAME(ZONE_WRITE_LOCK),
+ SCSI_CMD_FLAG_NAME(INITIALIZED),
+};
+#undef SCSI_CMD_FLAG_NAME
+
+static int scsi_flags_show(struct seq_file *m, const unsigned long flags,
+ const char *const *flag_name, int flag_name_count)
+{
+ bool sep = false;
+ int i;
+
+ for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
+ if (!(flags & BIT(i)))
+ continue;
+ if (sep)
+ seq_puts(m, "|");
+ sep = true;
+ if (i < flag_name_count && flag_name[i])
+ seq_puts(m, flag_name[i]);
+ else
+ seq_printf(m, "%d", i);
+ }
+ return 0;
+}
+
void scsi_show_rq(struct seq_file *m, struct request *rq)
{
struct scsi_cmnd *cmd = container_of(scsi_req(rq), typeof(*cmd), req);
- int msecs = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc);
+ int alloc_ms = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc);
+ int timeout_ms = jiffies_to_msecs(rq->timeout);
const u8 *const cdb = READ_ONCE(cmd->cmnd);
char buf[80] = "(?)";
if (cdb)
__scsi_format_command(buf, sizeof(buf), cdb, cmd->cmd_len);
- seq_printf(m, ", .cmd=%s, .retries=%d, allocated %d.%03d s ago", buf,
- cmd->retries, msecs / 1000, msecs % 1000);
+ seq_printf(m, ", .cmd=%s, .retries=%d, .result = %#x, .flags=", buf,
+ cmd->retries, cmd->result);
+ scsi_flags_show(m, cmd->flags, scsi_cmd_flags,
+ ARRAY_SIZE(scsi_cmd_flags));
+ seq_printf(m, ", .timeout=%d.%03d, allocated %d.%03d s ago",
+ timeout_ms / 1000, timeout_ms % 1000,
+ alloc_ms / 1000, alloc_ms % 1000);
}
--
2.15.0
