block: Define and use STAT_READ and STAT_WRITE
Add defines for STAT_READ and STAT_WRITE for indexing the partition
stat entries. This clarifies some fs/ code which has hardcoded 1 for
STAT_WRITE and will make it easier to extend the stats with additional
fields.
tj: Refreshed on top of v4.17.
Signed-off-by: Michael Callahan <michaelcallahan@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/genhd.c b/block/genhd.c
index f1543a4..0711a80 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1337,14 +1337,14 @@ static int diskstats_show(struct seq_file *seqf, void *v)
"%u %lu %lu %lu %u %u %u %u\n",
MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
disk_name(gp, hd->partno, buf),
- part_stat_read(hd, ios[READ]),
- part_stat_read(hd, merges[READ]),
- part_stat_read(hd, sectors[READ]),
- jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
- part_stat_read(hd, ios[WRITE]),
- part_stat_read(hd, merges[WRITE]),
- part_stat_read(hd, sectors[WRITE]),
- jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
+ part_stat_read(hd, ios[STAT_READ]),
+ part_stat_read(hd, merges[STAT_READ]),
+ part_stat_read(hd, sectors[STAT_READ]),
+ jiffies_to_msecs(part_stat_read(hd, ticks[STAT_READ])),
+ part_stat_read(hd, ios[STAT_WRITE]),
+ part_stat_read(hd, merges[STAT_WRITE]),
+ part_stat_read(hd, sectors[STAT_WRITE]),
+ jiffies_to_msecs(part_stat_read(hd, ticks[STAT_WRITE])),
inflight[0],
jiffies_to_msecs(part_stat_read(hd, io_ticks)),
jiffies_to_msecs(part_stat_read(hd, time_in_queue))