diff options
| author | Coly Li <colyli@suse.de> | 2020-07-25 15:00:39 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-07-25 16:38:21 +0300 |
| commit | a2f32ee8fd853cec8860f883d98afc3a339546de (patch) | |
| tree | e66e47a1c79a051ee9d69221df1b6b253a31ff49 /drivers/md | |
| parent | 4e4d4e0962262c97ba4580716d11623384effdfd (diff) | |
| download | linux-a2f32ee8fd853cec8860f883d98afc3a339546de.tar.xz | |
bcache: fix bio_{start,end}_io_acct with proper device
Commit 85750aeb748f ("bcache: use bio_{start,end}_io_acct") moves the
io account code to the location after bio_set_dev(bio, dc->bdev) in
cached_dev_make_request(). Then the account is performed incorrectly on
backing device, indeed the I/O should be counted to bcache device like
/dev/bcache0.
With the mistaken I/O account, iostat does not display I/O counts for
bcache device and all the numbers go to backing device. In writeback
mode, the hard drive may have 340K+ IOPS which is impossible and wrong
for spinning disk.
This patch introduces bch_bio_start_io_acct() and bch_bio_end_io_acct(),
which switches bio->bi_disk to bcache device before calling
bio_start_io_acct() or bio_end_io_acct(). Now the I/Os are counted to
bcache device, and bcache device, cache device and backing device have
their correct I/O count information back.
Fixes: 85750aeb748f ("bcache: use bio_{start,end}_io_acct")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/bcache/request.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index dd012ebface0..11a7ecc00401 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -617,6 +617,28 @@ static void cache_lookup(struct closure *cl) /* Common code for the make_request functions */ +static inline void bch_bio_start_io_acct(struct gendisk *acct_bi_disk, + struct bio *bio, + unsigned long *start_time) +{ + struct gendisk *saved_bi_disk = bio->bi_disk; + + bio->bi_disk = acct_bi_disk; + *start_time = bio_start_io_acct(bio); + bio->bi_disk = saved_bi_disk; +} + +static inline void bch_bio_end_io_acct(struct gendisk *acct_bi_disk, + struct bio *bio, + unsigned long start_time) +{ + struct gendisk *saved_bi_disk = bio->bi_disk; + + bio->bi_disk = acct_bi_disk; + bio_end_io_acct(bio, start_time); + bio->bi_disk = saved_bi_disk; +} + static void request_endio(struct bio *bio) { struct closure *cl = bio->bi_private; @@ -668,7 +690,7 @@ static void backing_request_endio(struct bio *bio) static void bio_complete(struct search *s) { if (s->orig_bio) { - bio_end_io_acct(s->orig_bio, s->start_time); + bch_bio_end_io_acct(s->d->disk, s->orig_bio, s->start_time); trace_bcache_request_end(s->d, s->orig_bio); s->orig_bio->bi_status = s->iop.status; bio_endio(s->orig_bio); @@ -728,7 +750,7 @@ static inline struct search *search_alloc(struct bio *bio, s->recoverable = 1; s->write = op_is_write(bio_op(bio)); s->read_dirty_data = 0; - s->start_time = bio_start_io_acct(bio); + bch_bio_start_io_acct(d->disk, bio, &s->start_time); s->iop.c = d->c; s->iop.bio = NULL; @@ -1080,7 +1102,7 @@ static void detached_dev_end_io(struct bio *bio) bio->bi_end_io = ddip->bi_end_io; bio->bi_private = ddip->bi_private; - bio_end_io_acct(bio, ddip->start_time); + bch_bio_end_io_acct(ddip->d->disk, bio, ddip->start_time); if (bio->bi_status) { struct cached_dev *dc = container_of(ddip->d, @@ -1105,7 +1127,8 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio) */ ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO); ddip->d = d; - ddip->start_time = bio_start_io_acct(bio); + bch_bio_start_io_acct(d->disk, bio, &ddip->start_time); + ddip->bi_end_io = bio->bi_end_io; ddip->bi_private = bio->bi_private; bio->bi_end_io = detached_dev_end_io; |