md/raid10: call wait_barrier() for each request submitted.
wait_barrier() includes a counter, so we must call it precisely once
(unless balanced by allow_barrier()) for each request submitted.
Since
commit 20d0189b1012a37d2533a87fb451f7852f2418d1
block: Introduce new bio_split()
in 3.14-rc1, we don't call it for the extra requests generated when
we need to split a bio.
When this happens the counter goes negative, any resync/recovery will
never start, and "mdadm --stop" will hang.
Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: 20d0189b1012a37d2533a87fb451f7852f2418d1
Cc: stable@vger.kernel.org (3.14+)
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 33fc408..cb882aa 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1172,6 +1172,13 @@
int max_sectors;
int sectors;
+ /*
+ * Register the new request and wait if the reconstruction
+ * thread has put up a bar for new requests.
+ * Continue immediately if no resync is active currently.
+ */
+ wait_barrier(conf);
+
sectors = bio_sectors(bio);
while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
bio->bi_iter.bi_sector < conf->reshape_progress &&
@@ -1552,12 +1559,6 @@
md_write_start(mddev, bio);
- /*
- * Register the new request and wait if the reconstruction
- * thread has put up a bar for new requests.
- * Continue immediately if no resync is active currently.
- */
- wait_barrier(conf);
do {
