raid5-cache: check stripe finish out of order
stripes could finish out of order. Hence r5l_move_io_unit_list() of
__r5l_stripe_write_finished might not move any entry and leave
stripe_end_ios list empty.
This applies on top of http://marc.info/?l=linux-raid&m=144122700510667
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index ea14803..30c7e5e 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -550,8 +550,13 @@
spin_lock_irqsave(&log->io_list_lock, flags);
__r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
+ /* might move 0 entry */
r5l_move_io_unit_list(&log->flushed_ios, &log->stripe_end_ios,
IO_UNIT_STRIPE_END);
+ if (list_empty(&log->stripe_end_ios)) {
+ spin_unlock_irqrestore(&log->io_list_lock, flags);
+ return;
+ }
last = list_last_entry(&log->stripe_end_ios,
struct r5l_io_unit, log_sibling);