Re: [PATCH v5 10/10] scsi: Implement blk_mq_ops.show_rq()

Omar Sandoval
2017-04-25T21:39:56Z

On Tue, Apr 25, 2017 at 01:37:45PM -0700, Bart Van Assche wrote:
> Show the SCSI CDB, .eh_eflags and .result for pending SCSI commands
> in /sys/kernel/debug/block/*/mq/*/dispatch and */rq_list.

Only thing I noticed was that the only other caller I see has buf[70].
No idea if that's a meaningful number. For the sake of this not getting
bike-shedded to death,

Reviewed-by: Omar Sandoval <osandov@fb.com>

> 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/Makefile | 1 +
> drivers/scsi/scsi_debugfs.c | 13 +++++++++++++
> drivers/scsi/scsi_debugfs.h | 4 ++++
> drivers/scsi/scsi_lib.c | 4 ++++
> 4 files changed, 22 insertions(+)
> create mode 100644 drivers/scsi/scsi_debugfs.c
> create mode 100644 drivers/scsi/scsi_debugfs.h
>
> diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
> index fc2855565a51..93dbe58c47c8 100644
> --- a/drivers/scsi/Makefile
> +++ b/drivers/scsi/Makefile
> @@ -166,6 +166,7 @@ scsi_mod-y += scsi_scan.o scsi_sysfs.o scsi_devinfo.o
> scsi_mod-$(CONFIG_SCSI_NETLINK) += scsi_netlink.o
> scsi_mod-$(CONFIG_SYSCTL) += scsi_sysctl.o
> scsi_mod-$(CONFIG_SCSI_PROC_FS) += scsi_proc.o
> +scsi_mod-$(CONFIG_BLK_DEBUG_FS) += scsi_debugfs.o
> scsi_mod-y += scsi_trace.o scsi_logging.o
> scsi_mod-$(CONFIG_PM) += scsi_pm.o
> scsi_mod-$(CONFIG_SCSI_DH) += scsi_dh.o
> diff --git a/drivers/scsi/scsi_debugfs.c b/drivers/scsi/scsi_debugfs.c
> new file mode 100644
> index 000000000000..f831c23fdee3
> --- /dev/null
> +++ b/drivers/scsi/scsi_debugfs.c
> @@ -0,0 +1,13 @@
> +#include <linux/seq_file.h>
> +#include <scsi/scsi_cmnd.h>
> +#include <scsi/scsi_dbg.h>
> +#include "scsi_debugfs.h"
> +
> +void scsi_show_rq(struct seq_file *m, struct request *rq)
> +{
> + struct scsi_cmnd *cmd = container_of(scsi_req(rq), typeof(*cmd), req);
> + char buf[64];
> +
> + __scsi_format_command(buf, sizeof(buf), cmd->cmnd, cmd->cmd_len);
> + seq_printf(m, ", .cmd=%s", buf);
> +}
> diff --git a/drivers/scsi/scsi_debugfs.h b/drivers/scsi/scsi_debugfs.h
> new file mode 100644
> index 000000000000..951b043e82d0
> --- /dev/null
> +++ b/drivers/scsi/scsi_debugfs.h
> @@ -0,0 +1,4 @@
> +struct request;
> +struct seq_file;
> +
> +void scsi_show_rq(struct seq_file *m, struct request *rq);
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index abc391e00f7d..1c3e87d6c48f 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -34,6 +34,7 @@
>
> #include <trace/events/scsi.h>
>
> +#include "scsi_debugfs.h"
> #include "scsi_priv.h"
> #include "scsi_logging.h"
>
> @@ -2157,6 +2158,9 @@ static const struct blk_mq_ops scsi_mq_ops = {
> .queue_rq = scsi_queue_rq,
> .complete = scsi_softirq_done,
> .timeout = scsi_timeout,
> +#ifdef CONFIG_BLK_DEBUG_FS
> + .show_rq = scsi_show_rq,
> +#endif
> .init_request = scsi_init_request,
> .exit_request = scsi_exit_request,
> .map_queues = scsi_map_queues,
> --
> 2.12.2
>