diff options
| author | Mike Snitzer <snitzer@kernel.org> | 2022-03-26 21:08:36 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2022-05-05 17:31:34 -0400 |
| commit | 563a225c9fd207326c2a2af9d59b4097cb31ce70 (patch) | |
| tree | 689fb3a68efff475af00c41c1b1a58a7792d50e2 /drivers/md/dm.c | |
| parent | 982b48ae25d9aabd69c1f012a94f63766181f0b2 (diff) | |
dm: introduce dm_{get,put}_live_table_bio called from dm_submit_bio
If a bio is marked REQ_NOWAIT optimize dm_submit_bio()'s dm_table RCU
usage to dm_{get,put}_live_table_fast.
DM core offers protection against blocking (via suspend) if REQ_NOWAIT.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md/dm.c')
| -rw-r--r-- | drivers/md/dm.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 152545ef00fa..d7b7154edffd 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -661,14 +661,16 @@ static void queue_io(struct mapped_device *md, struct bio *bio) * function to access the md->map field, and make sure they call * dm_put_live_table() when finished. */ -struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier) +struct dm_table *dm_get_live_table(struct mapped_device *md, + int *srcu_idx) __acquires(md->io_barrier) { *srcu_idx = srcu_read_lock(&md->io_barrier); return srcu_dereference(md->map, &md->io_barrier); } -void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier) +void dm_put_live_table(struct mapped_device *md, + int srcu_idx) __releases(md->io_barrier) { srcu_read_unlock(&md->io_barrier, srcu_idx); } @@ -694,6 +696,24 @@ static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) rcu_read_unlock(); } +static inline struct dm_table *dm_get_live_table_bio(struct mapped_device *md, + int *srcu_idx, struct bio *bio) +{ + if (bio->bi_opf & REQ_NOWAIT) + return dm_get_live_table_fast(md); + else + return dm_get_live_table(md, srcu_idx); +} + +static inline void dm_put_live_table_bio(struct mapped_device *md, int srcu_idx, + struct bio *bio) +{ + if (bio->bi_opf & REQ_NOWAIT) + dm_put_live_table_fast(md); + else + dm_put_live_table(md, srcu_idx); +} + static char *_dm_claim_ptr = "I belong to device-mapper"; /* @@ -1612,7 +1632,7 @@ static void dm_submit_bio(struct bio *bio) int srcu_idx; struct dm_table *map; - map = dm_get_live_table(md, &srcu_idx); + map = dm_get_live_table_bio(md, &srcu_idx, bio); /* If suspended, or map not yet available, queue this IO for later */ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) || @@ -1635,7 +1655,7 @@ static void dm_submit_bio(struct bio *bio) dm_split_and_process_bio(md, map, bio); out: - dm_put_live_table(md, srcu_idx); + dm_put_live_table_bio(md, srcu_idx, bio); } static bool dm_poll_dm_io(struct dm_io *io, struct io_comp_batch *iob, |