[PATCH 20/35] dm: pass dm stats data dir instead of bi_rw

mchristi
2016-01-05T20:55:04Z

It looks like dm stats cares about the data direction
(READ vs WRITE) and does not need the bio/request flags.
Commands like REQ_FLUSH, REQ_DISCARD and REQ_WRITE_SAME
are currently always set with REQ_WRITE, so the extra check for
REQ_DISCARD in dm_stats_account_io is not needed.

This patch has it use the bio and request data_dir helpers
instead of accessing the bi_rw/cmd_flags directly. This makes
the next patches that remove the operation from the cmd_flags
and bi_rw easier, because we will no longer have the REQ_WRITE
bit set for operations like discards.

This patch is compile tested only.

Signed-off-by: Mike Christie <mchristi@redhat.com>
---
drivers/md/dm-stats.c | 6 +++---
drivers/md/dm.c | 8 ++++----
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c
index 8289804..96b5c1b 100644
--- a/drivers/md/dm-stats.c
+++ b/drivers/md/dm-stats.c
@@ -518,7 +518,7 @@ static void dm_stat_for_entry(struct dm_stat *s, size_t entry,
struct dm_stats_aux *stats_aux, bool end,
unsigned long duration_jiffies)
{
- unsigned long idx = bi_rw & REQ_WRITE;
+ unsigned long idx = bi_rw;
struct dm_stat_shared *shared = &s->stat_shared[entry];
struct dm_stat_percpu *p;

@@ -645,8 +645,8 @@ void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
last = raw_cpu_ptr(stats->last);
stats_aux->merged =
(bi_sector == (ACCESS_ONCE(last->last_sector) &&
- ((bi_rw & (REQ_WRITE | REQ_DISCARD)) ==
- (ACCESS_ONCE(last->last_rw) & (REQ_WRITE | REQ_DISCARD)))
+ ((bi_rw == WRITE) ==
+ (ACCESS_ONCE(last->last_rw) == WRITE))
));
ACCESS_ONCE(last->last_sector) = end_sector;
ACCESS_ONCE(last->last_rw) = bi_rw;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 1777c9c..5dbdae7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -686,7 +686,7 @@ static void start_io_acct(struct dm_io *io)
atomic_inc_return(&md->pending[rw]));

if (unlikely(dm_stats_used(&md->stats)))
- dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector,
+ dm_stats_account_io(&md->stats, bio_data_dir(bio), bio->bi_iter.bi_sector,
bio_sectors(bio), false, 0, &io->stats_aux);
}

@@ -701,7 +701,7 @@ static void end_io_acct(struct dm_io *io)
generic_end_io_acct(rw, &dm_disk(md)->part0, io->start_time);

if (unlikely(dm_stats_used(&md->stats)))
- dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector,
+ dm_stats_account_io(&md->stats, bio_data_dir(bio), bio->bi_iter.bi_sector,
bio_sectors(bio), true, duration, &io->stats_aux);

/*
@@ -1084,7 +1084,7 @@ static void rq_end_stats(struct mapped_device *md, struct request *orig)
if (unlikely(dm_stats_used(&md->stats))) {
struct dm_rq_target_io *tio = tio_from_request(orig);
tio->duration_jiffies = jiffies - tio->duration_jiffies;
- dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
+ dm_stats_account_io(&md->stats, rq_data_dir(orig), blk_rq_pos(orig),
tio->n_sectors, true, tio->duration_jiffies,
&tio->stats_aux);
}
@@ -2017,7 +2017,7 @@ static void dm_start_request(struct mapped_device *md, struct request *orig)
struct dm_rq_target_io *tio = tio_from_request(orig);
tio->duration_jiffies = jiffies;
tio->n_sectors = blk_rq_sectors(orig);
- dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
+ dm_stats_account_io(&md->stats, rq_data_dir(orig), blk_rq_pos(orig),
tio->n_sectors, false, 0, &tio->stats_aux);
}

--
1.8.3.1