From: John Garry <[email protected]> Failover occurs when the scsi_cmnd has failed and it is discovered that the target scsi_device has transport down.
For a scsi command which suffers failover, requeue the master bio of each bio attached to its request. A bio which for which failover occurs is handled in scsi_mpath_clone_end_io(). Failover is detected for blk_path_error() occuring, same as how dm-mpath detects this. Signed-off-by: John Garry <[email protected]> --- drivers/scsi/scsi_multipath.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c index 456351fee4b98..12200664ed676 100644 --- a/drivers/scsi/scsi_multipath.c +++ b/drivers/scsi/scsi_multipath.c @@ -256,10 +256,34 @@ void scsi_mpath_dev_clear_path(struct scsi_mpath_device *scsi_mpath_dev) mpath_synchronize(mpath_head); } +static inline void bio_list_add_master(struct bio_list *bl, + struct bio *master_bio) +{ + if (bl->tail) + bl->tail->bi_next = master_bio; + else + bl->head = master_bio; + bl->tail = master_bio; +} + static void scsi_mpath_clone_end_io(struct bio *clone) { struct bio *master_bio = clone->bi_private; + if (clone->bi_status && blk_path_error(clone->bi_status)) { + struct mpath_head *mpath_head = + master_bio->bi_bdev->bd_disk->private_data; + unsigned long flags; + + spin_lock_irqsave(&mpath_head->requeue_lock, flags); + bio_list_add_master(&mpath_head->requeue_list, master_bio); + spin_unlock_irqrestore(&mpath_head->requeue_lock, flags); + bio_put(clone); + + mpath_schedule_requeue_work(mpath_head); + return; + } + master_bio->bi_status = clone->bi_status; bio_put(clone); bio_endio(master_bio); -- 2.43.7
