noclone_endio() must call the target's ->endio method if it exists. Also must handle the various DM_ENDIO_* returns that are possible.
Factor out dm_bio_pushback_needed() for both dec_pending() and noclone_endio() to use when handling BLK_STS_DM_REQUEUE. Lastly, there is no need to conditionally set md->immutable_target in __bind(). If the device only uses a single immutable target then it should always be reflected in md->immutable_target. This is important because noclone_endio() benefits from this to get access to the multipath dm_target without needing to add another member to the 'dm_noclone' structure. Signed-off-by: Mike Snitzer <[email protected]> --- drivers/md/dm.c | 80 ++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 57 insertions(+), 23 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 7e022f840419..0943913bceca 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -919,6 +919,28 @@ static int __noflush_suspending(struct mapped_device *md) return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags); } +static bool dm_bio_pushback_needed(struct mapped_device *md, + struct bio *bio, blk_status_t *error) +{ + unsigned long flags; + + /* + * Target requested pushing back the I/O. + */ + if (__noflush_suspending(md)) { + spin_lock_irqsave(&md->deferred_lock, flags); + // FIXME: using bio_list_add_head() creates LIFO + bio_list_add_head(&md->deferred, bio); + spin_unlock_irqrestore(&md->deferred_lock, flags); + return true; + } else { + /* noflush suspend was interrupted. */ + *error = BLK_STS_IOERR; + } + + return false; +} + /* * Decrements the number of outstanding ios that a bio has been * cloned into, completing the original io if necc. @@ -939,22 +961,12 @@ static void dec_pending(struct dm_io *io, blk_status_t error) } if (atomic_dec_and_test(&io->io_count)) { - if (io->status == BLK_STS_DM_REQUEUE) { - /* - * Target requested pushing back the I/O. - */ - spin_lock_irqsave(&md->deferred_lock, flags); - if (__noflush_suspending(md)) - /* NOTE early return due to BLK_STS_DM_REQUEUE below */ - bio_list_add_head(&md->deferred, io->orig_bio); - else - /* noflush suspend was interrupted. */ - io->status = BLK_STS_IOERR; - spin_unlock_irqrestore(&md->deferred_lock, flags); - } + bio = io->orig_bio; + + if (unlikely(io->status == BLK_STS_DM_REQUEUE)) + (void) dm_bio_pushback_needed(md, bio, &io->status); io_error = io->status; - bio = io->orig_bio; if (unlikely(dm_stats_used(&md->stats))) { unsigned long duration = jiffies - io->start_time; @@ -1041,8 +1053,33 @@ static void clone_endio(struct bio *bio) static void noclone_endio(struct bio *bio) { + blk_status_t error = bio->bi_status; struct dm_noclone *noclone = bio->bi_private; struct mapped_device *md = noclone->md; + struct dm_target *ti = NULL; + dm_endio_fn endio = NULL; + + if (md->immutable_target) { + ti = md->immutable_target; + endio = ti->type->end_io; + } + + if (endio) { + int r = endio(ti, bio, &error); + switch (r) { + case DM_ENDIO_REQUEUE: + error = BLK_STS_DM_REQUEUE; + /*FALLTHRU*/ + case DM_ENDIO_DONE: + break; + case DM_ENDIO_INCOMPLETE: + /* The target will handle the io */ + return; + default: + DMWARN("unimplemented target endio return value: %d", r); + BUG(); + } + } end_io_acct(md, bio, noclone->start_time); @@ -1050,6 +1087,11 @@ static void noclone_endio(struct bio *bio) bio->bi_private = noclone->orig_bi_private; kfree(noclone); + if (unlikely(error == BLK_STS_DM_REQUEUE)) { + if (dm_bio_pushback_needed(md, bio, &bio->bi_status)) + return; + } + bio_endio(bio); } @@ -2249,15 +2291,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, if (request_based) dm_stop_queue(q); - if (request_based || md->type == DM_TYPE_NVME_BIO_BASED) { - /* - * Leverage the fact that request-based DM targets and - * NVMe bio based targets are immutable singletons - * - used to optimize both dm_request_fn and dm_mq_queue_rq; - * and __process_bio. - */ - md->immutable_target = dm_table_get_immutable_target(t); - } + md->immutable_target = dm_table_get_immutable_target(t); ret = __bind_mempools(md, t); if (ret) { -- 2.15.0 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
