This is a note to let you know that I've just added the patch titled bcache: use disk_{start,end}_io_acct() to count I/O for bcache device to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bcache-use-disk_-start-end-_io_acct-to-count-i-o-for-bcache-device.patch and it can be found in the queue-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c5be1f2c5bab1538aa29cd42e226d6b80391e3ff Mon Sep 17 00:00:00 2001 From: Coly Li <colyli@xxxxxxx> Date: Tue, 28 Jul 2020 21:59:20 +0800 Subject: bcache: use disk_{start,end}_io_acct() to count I/O for bcache device From: Coly Li <colyli@xxxxxxx> commit c5be1f2c5bab1538aa29cd42e226d6b80391e3ff upstream. This patch is a fix to patch "bcache: fix bio_{start,end}_io_acct with proper device". The previous patch uses a hack to temporarily set bi_disk to bcache device, which is mistaken too. As Christoph suggests, this patch uses disk_{start,end}_io_acct() to count I/O for bcache device in the correct way. Fixes: 85750aeb748f ("bcache: use bio_{start,end}_io_acct") Signed-off-by: Coly Li <colyli@xxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/bcache/request.c | 37 +++++++++---------------------------- 1 file changed, 9 insertions(+), 28 deletions(-) --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -617,28 +617,6 @@ static void cache_lookup(struct closure /* 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; @@ -690,7 +668,9 @@ static void backing_request_endio(struct static void bio_complete(struct search *s) { if (s->orig_bio) { - bch_bio_end_io_acct(s->d->disk, s->orig_bio, s->start_time); + /* Count on bcache device */ + disk_end_io_acct(s->d->disk, bio_op(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); @@ -750,8 +730,8 @@ static inline struct search *search_allo s->recoverable = 1; s->write = op_is_write(bio_op(bio)); s->read_dirty_data = 0; - bch_bio_start_io_acct(d->disk, bio, &s->start_time); - + /* Count on the bcache device */ + s->start_time = disk_start_io_acct(d->disk, bio_sectors(bio), bio_op(bio)); s->iop.c = d->c; s->iop.bio = NULL; s->iop.inode = d->id; @@ -1102,7 +1082,8 @@ static void detached_dev_end_io(struct b bio->bi_end_io = ddip->bi_end_io; bio->bi_private = ddip->bi_private; - bch_bio_end_io_acct(ddip->d->disk, bio, ddip->start_time); + /* Count on the bcache device */ + disk_end_io_acct(ddip->d->disk, bio_op(bio), ddip->start_time); if (bio->bi_status) { struct cached_dev *dc = container_of(ddip->d, @@ -1127,8 +1108,8 @@ static void detached_dev_do_request(stru */ ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO); ddip->d = d; - bch_bio_start_io_acct(d->disk, bio, &ddip->start_time); - + /* Count on the bcache device */ + ddip->start_time = disk_start_io_acct(d->disk, bio_sectors(bio), bio_op(bio)); ddip->bi_end_io = bio->bi_end_io; ddip->bi_private = bio->bi_private; bio->bi_end_io = detached_dev_end_io; Patches currently in stable-queue which might be from colyli@xxxxxxx are queue-5.8/bcache-fix-overflow-in-offset_to_stripe.patch queue-5.8/bcache-use-disk_-start-end-_io_acct-to-count-i-o-for-bcache-device.patch queue-5.8/bcache-avoid-nr_stripes-overflow-in-bcache_device_init.patch queue-5.8/bcache-fix-bio_-start-end-_io_acct-with-proper-device.patch queue-5.8/bcache-allocate-meta-data-pages-as-compound-pages.patch