DM needs the ability to account a clone bio's IO to the original block_device. So add @orig_bdev argument to bio_start_io_acct_time. Rename bio_start_io_acct_time to bio_start_io_acct_remapped. Also, follow bio_end_io_acct and bio_end_io_acct_remapped pattern by moving bio_start_io_acct to blkdev.h and have it call bio_start_io_acct_remapped.
Improve DM to no longer need to play games with swizzling a clone bio's bi_bdev (in dm_submit_bio_remap) and remove DM's clone_and_start_io_acct() interface. Signed-off-by: Mike Snitzer <[email protected]> --- block/blk-core.c | 24 ++++++++---------------- drivers/md/dm.c | 41 ++++++++--------------------------------- include/linux/blkdev.h | 16 ++++++++++++++-- 3 files changed, 30 insertions(+), 51 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index be8812f5489d..8f23be96c737 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1077,29 +1077,21 @@ static unsigned long __part_start_io_acct(struct block_device *part, } /** - * bio_start_io_acct_time - start I/O accounting for bio based drivers + * bio_start_io_acct_remapped - 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 - * @bio: bio to start account for + * @orig_bdev: block device that I/O must be accounted to. * * Returns the start time that should be passed back to bio_end_io_acct(). */ -unsigned long bio_start_io_acct(struct bio *bio) +unsigned long bio_start_io_acct_remapped(struct bio *bio, + unsigned long start_time, + struct block_device *orig_bdev) { - return __part_start_io_acct(bio->bi_bdev, bio_sectors(bio), - bio_op(bio), jiffies); + return __part_start_io_acct(orig_bdev, bio_sectors(bio), + bio_op(bio), start_time); } -EXPORT_SYMBOL_GPL(bio_start_io_acct); +EXPORT_SYMBOL_GPL(bio_start_io_acct_remapped); unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, unsigned int op) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 329f0be64523..e020f505e243 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -485,35 +485,19 @@ u64 dm_start_time_ns_from_clone(struct bio *bio) } EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone); -static void __start_io_acct(struct dm_io *io, struct bio *bio) -{ - bio_start_io_acct_time(bio, io->start_time); - if (unlikely(dm_stats_used(&io->md->stats))) - dm_stats_account_io(&io->md->stats, bio_data_dir(bio), - bio->bi_iter.bi_sector, bio_sectors(bio), - false, 0, &io->stats_aux); -} - static void start_io_acct(struct dm_io *io, struct bio *bio) { /* Ensure IO accounting is only ever started once */ if (xchg(&io->was_accounted, 1) == 1) return; - __start_io_acct(io, bio); -} + bio_start_io_acct_remapped(bio, io->start_time, + io->orig_bio->bi_bdev); -static void clone_and_start_io_acct(struct dm_io *io, struct bio *bio) -{ - struct bio io_acct_clone; - - /* Ensure IO accounting is only ever started once */ - if (xchg(&io->was_accounted, 1) == 1) - return; - - bio_init_clone(io->orig_bio->bi_bdev, - &io_acct_clone, bio, GFP_NOIO); - __start_io_acct(io, &io_acct_clone); + if (unlikely(dm_stats_used(&io->md->stats))) + dm_stats_account_io(&io->md->stats, bio_data_dir(bio), + bio->bi_iter.bi_sector, bio_sectors(bio), + false, 0, &io->stats_aux); } static void end_io_acct(struct mapped_device *md, struct bio *bio, @@ -1137,7 +1121,6 @@ void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone) { struct dm_target_io *tio = clone_to_tio(clone); struct dm_io *io = tio->io; - struct block_device *clone_bdev = clone->bi_bdev; /* establish bio that will get submitted */ if (!tgt_clone) @@ -1151,9 +1134,7 @@ void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone) * io->orig_bio so there is no IO imbalance in * end_io_acct(). */ - clone->bi_bdev = io->orig_bio->bi_bdev; start_io_acct(io, clone); - clone->bi_bdev = clone_bdev; trace_block_bio_remap(tgt_clone, bio_dev(io->orig_bio), tio->old_sector); @@ -1213,14 +1194,8 @@ static void __map_bio(struct bio *clone) switch (r) { case DM_MAPIO_SUBMITTED: /* target has assumed ownership of this io */ - if (!ti->accounts_remapped_io) { - /* - * Any split isn't reflected in io->orig_bio yet. And bio - * cannot be modified because target is submitting it. - * Clone bio and account IO to DM device. - */ - clone_and_start_io_acct(io, clone); - } + if (!ti->accounts_remapped_io) + start_io_acct(io, clone); break; case DM_MAPIO_REMAPPED: /* the bio has been remapped so dispatch it */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3bfc75a2a450..31d055d4a17e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1512,11 +1512,23 @@ 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); +unsigned long bio_start_io_acct_remapped(struct bio *bio, + unsigned long start_time, + struct block_device *orig_bdev); void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time, struct block_device *orig_bdev); +/** + * bio_start_io_acct - start I/O accounting for bio based drivers + * @bio: bio to start account for + * + * Returns the start time that should be passed back to bio_end_io_acct(). + */ +static inline unsigned long bio_start_io_acct(struct bio *bio) +{ + return bio_start_io_acct_remapped(bio, jiffies, bio->bi_bdev); +} + /** * bio_end_io_acct - end I/O accounting for bio based drivers * @bio: bio to end account for -- 2.15.0 -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
