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Commit bd49784f authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
Browse files

dm stats: report precise_timestamps and histogram in @stats_list output 



If the user selected the precise_timestamps or histogram options, report
it in the @stats_list message output.

If the user didn't select these options, no extra tokens are reported,
thus it is backward compatible with old software that doesn't know about
precise timestamps and histogram.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.2
parent 84f8bd86

Documentation/device-mapper/statistics.txt

+4 −0
Original line number Diff line number Diff line
@@ -121,6 +121,10 @@ Messages 


	Output format:

	  <region_id>: <start_sector>+<length> <step> <program_id> <aux_data>

	        precise_timestamps histogram:n1,n2,n3,...



	The strings "precise_timestamps" and "histogram" are printed only

	if they were specified when creating the region.



    @stats_print <region_id> [<starting_line> <number_of_lines>]

drivers/md/dm-stats.c

+13 −1
Original line number Diff line number Diff line
@@ -457,12 +457,24 @@ static int dm_stats_list(struct dm_stats *stats, const char *program, 
	list_for_each_entry(s, &stats->list, list_entry) {

		if (!program || !strcmp(program, s->program_id)) {

			len = s->end - s->start;

			DMEMIT("%d: %llu+%llu %llu %s %s\n", s->id,

			DMEMIT("%d: %llu+%llu %llu %s %s", s->id,

				(unsigned long long)s->start,

				(unsigned long long)len,

				(unsigned long long)s->step,

				s->program_id,

				s->aux_data);

			if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)

				DMEMIT(" precise_timestamps");

			if (s->n_histogram_entries) {

				unsigned i;

				DMEMIT(" histogram:");

				for (i = 0; i < s->n_histogram_entries; i++) {

					if (i)

						DMEMIT(",");

					DMEMIT("%llu", s->histogram_boundaries[i]);

				}

			}

			DMEMIT("\n");

		}

	}

	mutex_unlock(&stats->mutex);

include/uapi/linux/dm-ioctl.h

+2 −2
Original line number Diff line number Diff line
@@ -267,9 +267,9 @@ enum { 
#define DM_DEV_SET_GEOMETRY	_IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)



#define DM_VERSION_MAJOR	4

#define DM_VERSION_MINOR	32

#define DM_VERSION_MINOR	33

#define DM_VERSION_PATCHLEVEL	0

#define DM_VERSION_EXTRA	"-ioctl (2015-6-26)"

#define DM_VERSION_EXTRA	"-ioctl (2015-8-18)"



/* Status bits */

#define DM_READONLY_FLAG	(1 << 0) /* In/Out */