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authorColy Li <colyli@suse.de>2020-07-25 15:00:39 +0300
committerJens Axboe <axboe@kernel.dk>2020-07-25 16:38:21 +0300
commita2f32ee8fd853cec8860f883d98afc3a339546de (patch)
treee66e47a1c79a051ee9d69221df1b6b253a31ff49 /drivers/md
parent4e4d4e0962262c97ba4580716d11623384effdfd (diff)
downloadlinux-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.c31
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;