diff options
| -rw-r--r-- | drivers/md/dm-mpath.c | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index d325edcbb3f..3aa01350696 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -282,6 +282,23 @@ failed: m->current_pg = NULL; } +/* + * Check whether bios must be queued in the device-mapper core rather + * than here in the target. + * + * m->lock must be held on entry. + * + * If m->queue_if_no_path and m->saved_queue_if_no_path hold the + * same value then we are not between multipath_presuspend() + * and multipath_resume() calls and we have no need to check + * for the DMF_NOFLUSH_SUSPENDING flag. + */ +static int __must_push_back(struct multipath *m) +{ + return (m->queue_if_no_path != m->saved_queue_if_no_path && + dm_noflush_suspending(m->ti)); +} + static int map_io(struct multipath *m, struct bio *bio, struct mpath_io *mpio, unsigned was_queued) { @@ -311,10 +328,12 @@ static int map_io(struct multipath *m, struct bio *bio, struct mpath_io *mpio, queue_work(kmultipathd, &m->process_queued_ios); pgpath = NULL; r = DM_MAPIO_SUBMITTED; - } else if (!pgpath) - r = -EIO; /* Failed */ - else + } else if (pgpath) bio->bi_bdev = pgpath->path.dev->bdev; + else if (__must_push_back(m)) + r = DM_MAPIO_REQUEUE; + else + r = -EIO; /* Failed */ mpio->pgpath = pgpath; @@ -374,6 +393,8 @@ static void dispatch_queued_ios(struct multipath *m) bio_endio(bio, bio->bi_size, r); else if (r == DM_MAPIO_REMAPPED) generic_make_request(bio); + else if (r == DM_MAPIO_REQUEUE) + bio_endio(bio, bio->bi_size, -EIO); bio = next; } @@ -783,7 +804,7 @@ static int multipath_map(struct dm_target *ti, struct bio *bio, map_context->ptr = mpio; bio->bi_rw |= (1 << BIO_RW_FAILFAST); r = map_io(m, bio, mpio, 0); - if (r < 0) + if (r < 0 || r == DM_MAPIO_REQUEUE) mempool_free(mpio, m->mpio_pool); return r; @@ -1007,7 +1028,10 @@ static int do_end_io(struct multipath *m, struct bio *bio, spin_lock_irqsave(&m->lock, flags); if (!m->nr_valid_paths) { - if (!m->queue_if_no_path) { + if (__must_push_back(m)) { + spin_unlock_irqrestore(&m->lock, flags); + return DM_ENDIO_REQUEUE; + } else if (!m->queue_if_no_path) { spin_unlock_irqrestore(&m->lock, flags); return -EIO; } else { |