[PATCH AUTOSEL 5.16 51/52] block: add bio_start_io_acct_time() to control start_time

Sasha Levin
2022-02-03T20:34:19Z

From: Mike Snitzer <snitzer@redhat.com>

[ Upstream commit e45c47d1f94e0cc7b6b079fdb4bcce2995e2adc4 ]

bio_start_io_acct_time() interface is like bio_start_io_acct() that
allows start_time to be passed in. This gives drivers the ability to
defer starting accounting until after IO is issued (but possibily not
entirely due to bio splitting).

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220128155841.39644-2-snitzer@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/blk-core.c | 25 +++++++++++++++++++------
include/linux/blkdev.h | 1 +
2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 1378d084c770f..9ebeb9bdf5832 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1258,20 +1258,32 @@ void __blk_account_io_start(struct request *rq)
}

static unsigned long __part_start_io_acct(struct block_device *part,
- unsigned int sectors, unsigned int op)
+ unsigned int sectors, unsigned int op,
+ unsigned long start_time)
{
const int sgrp = op_stat_group(op);
- unsigned long now = READ_ONCE(jiffies);

part_stat_lock();
- update_io_ticks(part, now, false);
+ update_io_ticks(part, start_time, false);
part_stat_inc(part, ios[sgrp]);
part_stat_add(part, sectors[sgrp], sectors);
part_stat_local_inc(part, in_flight[op_is_write(op)]);
part_stat_unlock();

- return now;
+ return start_time;
+}
+
+/**
+ * bio_start_io_acct_time - start I/O accounting for bio based drivers
+ * @bio: bio to start account for
+ * @start_time: start time that should be passed back to bio_end_io_acct().
+ */
+void bio_start_io_acct_time(struct bio *bio, unsigned long start_time)
+{
+ __part_start_io_acct(bio->bi_bdev, bio_sectors(bio),
+ bio_op(bio), start_time);
}
+EXPORT_SYMBOL_GPL(bio_start_io_acct_time);

/**
* bio_start_io_acct - start I/O accounting for bio based drivers
@@ -1281,14 +1293,15 @@ static unsigned long __part_start_io_acct(struct block_device *part,
*/
unsigned long bio_start_io_acct(struct bio *bio)
{
- return __part_start_io_acct(bio->bi_bdev, bio_sectors(bio), bio_op(bio));
+ return __part_start_io_acct(bio->bi_bdev, bio_sectors(bio),
+ bio_op(bio), jiffies);
}
EXPORT_SYMBOL_GPL(bio_start_io_acct);

unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
unsigned int op)
{
- return __part_start_io_acct(disk->part0, sectors, op);
+ return __part_start_io_acct(disk->part0, sectors, op, jiffies);
}
EXPORT_SYMBOL(disk_start_io_acct);

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bd4370baccca3..d73887c805e05 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1254,6 +1254,7 @@ unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
void disk_end_io_acct(struct gendisk *disk, unsigned int op,
unsigned long start_time);

+void bio_start_io_acct_time(struct bio *bio, unsigned long start_time);
unsigned long bio_start_io_acct(struct bio *bio);
void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time,
struct block_device *orig_bdev);
--
2.34.1