From b7f8dff09827c96032c34a945ee7757e394b5952 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 10 Mar 2022 11:45:58 -0500 Subject: [PATCH] dm: simplify dm_sumbit_bio_remap interface Remove the from_wq argument from dm_sumbit_bio_remap(). Eliminates the need for dm_sumbit_bio_remap() callers to know whether they are calling for a workqueue or from the original dm_submit_bio(). Add map_task to dm_io struct, record the map_task in alloc_io and clear it after all target ->map() calls have completed. Update dm_sumbit_bio_remap to check if 'current' matches io->map_task rather than rely on passed 'from_rq' argument. This change really simplifies the chore of porting each DM target to using dm_sumbit_bio_remap() because there is no longer the risk of programming error by not completely knowing all the different contexts a particular method that calls dm_sumbit_bio_remap() might be used in. Signed-off-by: Mike Snitzer --- drivers/md/dm-core.h | 1 + drivers/md/dm-crypt.c | 6 +++--- drivers/md/dm-delay.c | 2 +- drivers/md/dm-thin.c | 4 ++-- drivers/md/dm.c | 8 ++++---- include/linux/device-mapper.h | 2 +- 6 files changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index 8cc03c0c262e..8d3d11887343 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -237,6 +237,7 @@ struct dm_io { unsigned long start_time; void *data; struct hlist_node node; + struct task_struct *map_task; spinlock_t endio_lock; struct dm_stats_aux stats_aux; /* last member of dm_target_io is 'struct bio' */ diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index ec746cc4b1f8..a1730cc8ae27 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1857,7 +1857,7 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) return 1; } - dm_submit_bio_remap(io->base_bio, clone, (gfp != CRYPT_MAP_READ_GFP)); + dm_submit_bio_remap(io->base_bio, clone); return 0; } @@ -1883,7 +1883,7 @@ static void kcryptd_io_write(struct dm_crypt_io *io) { struct bio *clone = io->ctx.bio_out; - dm_submit_bio_remap(io->base_bio, clone, true); + dm_submit_bio_remap(io->base_bio, clone); } #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) @@ -1962,7 +1962,7 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) || test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) { - dm_submit_bio_remap(io->base_bio, clone, true); + dm_submit_bio_remap(io->base_bio, clone); return; } diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c index b25b45011b11..9a51bf51a859 100644 --- a/drivers/md/dm-delay.c +++ b/drivers/md/dm-delay.c @@ -72,7 +72,7 @@ static void flush_bios(struct bio *bio) while (bio) { n = bio->bi_next; bio->bi_next = NULL; - dm_submit_bio_remap(bio, NULL, true); + dm_submit_bio_remap(bio, NULL); bio = n; } } diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index ba74bc22ba42..4d25d0e27031 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -755,7 +755,7 @@ static void issue(struct thin_c *tc, struct bio *bio) struct pool *pool = tc->pool; if (!bio_triggers_commit(tc, bio)) { - dm_submit_bio_remap(bio, NULL, true); + dm_submit_bio_remap(bio, NULL); return; } @@ -2383,7 +2383,7 @@ static void process_deferred_bios(struct pool *pool) if (bio->bi_opf & REQ_PREFLUSH) bio_endio(bio); else - dm_submit_bio_remap(bio, NULL, true); + dm_submit_bio_remap(bio, NULL); } } diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 1c5c9036a20e..c470f54f9193 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -574,6 +574,7 @@ static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio) this_cpu_inc(*md->pending_io); io->orig_bio = NULL; io->md = md; + io->map_task = current; spin_lock_init(&io->endio_lock); io->start_time = jiffies; @@ -1189,15 +1190,13 @@ static inline void __dm_submit_bio_remap(struct bio *clone, /* * @clone: clone bio that DM core passed to target's .map function * @tgt_clone: clone of @clone bio that target needs submitted - * @from_wq: caller is a workqueue thread managed by DM target * * Targets should use this interface to submit bios they take * ownership of when returning DM_MAPIO_SUBMITTED. * * Target should also enable ti->accounts_remapped_io */ -void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone, - bool from_wq) +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; @@ -1212,7 +1211,7 @@ void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone, * Account io->origin_bio to DM dev on behalf of target * that took ownership of IO with DM_MAPIO_SUBMITTED. */ - if (!from_wq) { + if (io->map_task == current) { /* Still in target's map function */ io->start_io_acct = true; } else { @@ -1568,6 +1567,7 @@ static void dm_split_and_process_bio(struct mapped_device *md, } error = __split_and_process_bio(&ci); + ci.io->map_task = NULL; if (error || !ci.sector_count) goto out; diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 70cd9449275a..901ec191250c 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -471,7 +471,7 @@ int dm_suspended(struct dm_target *ti); int dm_post_suspending(struct dm_target *ti); int dm_noflush_suspending(struct dm_target *ti); void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors); -void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone, bool from_wq); +void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone); union map_info *dm_get_rq_mapinfo(struct request *rq); #ifdef CONFIG_BLK_DEV_ZONED