diff options
| author | Kent Overstreet <kmo@daterainc.com> | 2013-11-23 18:34:15 -0800 |
|---|---|---|
| committer | Kent Overstreet <kmo@daterainc.com> | 2013-11-23 22:33:56 -0800 |
| commit | 196d38bccfcfa32faed8c561868336fdfa0fe8e4 (patch) | |
| tree | 9dee2bc174436072c9e90ffebbe71f47fde63aaf /drivers/md | |
| parent | e90abc8ec323c1fd2a25600097ef7ae1e91f39b0 (diff) | |
block: Generic bio chaining
This adds a generic mechanism for chaining bio completions. This is
going to be used for a bio_split() replacement, and it turns out to be
very useful in a fair amount of driver code - a fair number of drivers
were implementing this in their own roundabout ways, often painfully.
Note that this means it's no longer to call bio_endio() more than once
on the same bio! This can cause problems for drivers that save/restore
bi_end_io. Arguably they shouldn't be saving/restoring bi_end_io at all
- in all but the simplest cases they'd be better off just cloning the
bio, and immutable biovecs is making bio cloning cheaper. But for now,
we add a bio_endio_nodec() for these cases.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/bcache/io.c | 2 | ||||
| -rw-r--r-- | drivers/md/dm-cache-target.c | 6 | ||||
| -rw-r--r-- | drivers/md/dm-snap.c | 1 | ||||
| -rw-r--r-- | drivers/md/dm-thin.c | 8 | ||||
| -rw-r--r-- | drivers/md/dm-verity.c | 2 |
5 files changed, 15 insertions, 4 deletions
diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c index 0f0ab659914d..522f95778443 100644 --- a/drivers/md/bcache/io.c +++ b/drivers/md/bcache/io.c @@ -133,7 +133,7 @@ static void bch_bio_submit_split_done(struct closure *cl) s->bio->bi_end_io = s->bi_end_io; s->bio->bi_private = s->bi_private; - bio_endio(s->bio, 0); + bio_endio_nodec(s->bio, 0); closure_debug_destroy(&s->cl); mempool_free(s, s->p->bio_split_hook); diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 86f9c83eb30c..bf3a206abd78 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -765,6 +765,12 @@ static void writethrough_endio(struct bio *bio, int err) dm_unhook_bio(&pb->hook_info, bio); + /* + * Must bump bi_remaining to allow bio to complete with + * restored bi_end_io. + */ + atomic_inc(&bio->bi_remaining); + if (err) { bio_endio(bio, err); return; diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 3ded8c729dfb..80b5cabbea29 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -1415,6 +1415,7 @@ out: if (full_bio) { full_bio->bi_end_io = pe->full_bio_end_io; full_bio->bi_private = pe->full_bio_private; + atomic_inc(&full_bio->bi_remaining); } free_pending_exception(pe); diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index a65402480c8c..1abb4a24c338 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -611,8 +611,10 @@ static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *c static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m) { - if (m->bio) + if (m->bio) { m->bio->bi_end_io = m->saved_bi_end_io; + atomic_inc(&m->bio->bi_remaining); + } cell_error(m->tc->pool, m->cell); list_del(&m->list); mempool_free(m, m->tc->pool->mapping_pool); @@ -626,8 +628,10 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m) int r; bio = m->bio; - if (bio) + if (bio) { bio->bi_end_io = m->saved_bi_end_io; + atomic_inc(&bio->bi_remaining); + } if (m->err) { cell_error(pool, m->cell); diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c index ac35e959d49b..796007a5e0e1 100644 --- a/drivers/md/dm-verity.c +++ b/drivers/md/dm-verity.c @@ -385,7 +385,7 @@ static void verity_finish_io(struct dm_verity_io *io, int error) bio->bi_end_io = io->orig_bi_end_io; bio->bi_private = io->orig_bi_private; - bio_endio(bio, error); + bio_endio_nodec(bio, error); } static void verity_work(struct work_struct *w) |