From e54f700d6ae3203221745c168dae20d88f2be4f1 Mon Sep 17 00:00:00 2001 From: Daniel Vacek Date: Wed, 2 Sep 2026 15:56:27 +0200 Subject: [PATCH] btrfs: use bio::remaining for async checksumming synchronization We can use bio::remaining counter to sync the offloaded checksumming. As a result we can slim down the btrfs_bio structure by 24 bytes and simplify the code a bit. Difference in pahole output: - /* size: 328, cachelines: 6, members: 15 */ + /* size: 304, cachelines: 5, members: 14 */ Moreover this will allow us enabling async checksumming with encryption where we need to checksum the bounce bio instead of our regular one embedded in btrfs_bio. And so we need to extend it's lifetime. This is the preferred way to do so. This also fixes a bug in experimental build where the async checksumming was using the system workqueue instead of fs_info::endio_workers. Fixes: dd57c78aec39 ("btrfs: introduce btrfs_bio::async_csum") Reviewed-by: Qu Wenruo Signed-off-by: Daniel Vacek Signed-off-by: David Sterba --- fs/btrfs/bio.c | 4 ---- fs/btrfs/bio.h | 4 ---- fs/btrfs/file-item.c | 8 +++----- 3 files changed, 3 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/bio.c b/fs/btrfs/bio.c index 19b4855969f5..771b7d598aee 100644 --- a/fs/btrfs/bio.c +++ b/fs/btrfs/bio.c @@ -103,7 +103,6 @@ static struct btrfs_bio *btrfs_split_bio(struct btrfs_fs_info *fs_info, bbio->can_use_append = orig_bbio->can_use_append; bbio->is_scrub = orig_bbio->is_scrub; bbio->is_remap = orig_bbio->is_remap; - bbio->async_csum = orig_bbio->async_csum; atomic_inc(&orig_bbio->pending_ios); return bbio; @@ -114,9 +113,6 @@ void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status) /* Make sure we're already in task context. */ ASSERT(in_task()); - if (bbio->async_csum) - wait_for_completion(&bbio->csum_done); - bbio->bio.bi_status = status; if (bbio->bio.bi_pool == &btrfs_clone_bioset) { struct btrfs_bio *orig_bbio = bbio->private; diff --git a/fs/btrfs/bio.h b/fs/btrfs/bio.h index b7bd377a0162..bbf362b8668b 100644 --- a/fs/btrfs/bio.h +++ b/fs/btrfs/bio.h @@ -58,7 +58,6 @@ struct btrfs_bio { struct btrfs_ordered_extent *ordered; struct btrfs_ordered_sum *sums; struct work_struct csum_work; - struct completion csum_done; struct bvec_iter csum_saved_iter; u64 orig_physical; u64 orig_logical; @@ -93,9 +92,6 @@ struct btrfs_bio { /* Whether the bio is coming from copy_remapped_data_io(). */ bool is_remap:1; - /* Whether the csum generation for data write is async. */ - bool async_csum:1; - /* Whether the bio is written using zone append. */ bool can_use_append:1; diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 2c6c14dfe393..ae1fd4da38d3 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -819,9 +819,8 @@ static void csum_one_bio_work(struct work_struct *work) struct btrfs_bio *bbio = container_of(work, struct btrfs_bio, csum_work); ASSERT(btrfs_op(&bbio->bio) == BTRFS_MAP_WRITE); - ASSERT(bbio->async_csum == true); csum_one_bio(bbio); - complete(&bbio->csum_done); + bio_endio(&bbio->bio); } /* @@ -855,10 +854,9 @@ int btrfs_csum_one_bio(struct btrfs_bio *bbio, bool async) csum_one_bio(bbio); return 0; } - init_completion(&bbio->csum_done); - bbio->async_csum = true; + bio_inc_remaining(bio); INIT_WORK(&bbio->csum_work, csum_one_bio_work); - schedule_work(&bbio->csum_work); + queue_work(fs_info->endio_workers, &bbio->csum_work); return 0; }