From e08f866978350ecc9dd90a2cfeb907b2abb74392 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Fri, 2 Feb 2018 23:13:19 +0100 Subject: md: fix md_write_start() deadlock w/o metadata devices [ Upstream commit 4b6c1060eaa6495aa5b0032e8f2d51dd936b1257 ] If no metadata devices are configured on raid1/4/5/6/10 (e.g. via dm-raid), md_write_start() unconditionally waits for superblocks to be written thus deadlocking. Fix introduces mddev->has_superblocks bool, defines it in md_run() and checks for it in md_write_start() to conditionally avoid waiting. Once on it, check for non-existing superblocks in md_super_write(). Link: https://bugzilla.kernel.org/show_bug.cgi?id=198647 Fixes: cc27b0c78c796 ("md: fix deadlock between mddev_suspend() and md_write_start()") Signed-off-by: Heinz Mauelshagen Signed-off-by: Shaohua Li Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/md/md.h') diff --git a/drivers/md/md.h b/drivers/md/md.h index d8287d3cd1bf..9b0a896890ef 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -462,6 +462,8 @@ struct mddev { void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); struct md_cluster_info *cluster_info; unsigned int good_device_nr; /* good device num within cluster raid */ + + bool has_superblocks:1; }; enum recovery_flags { -- cgit v1.2.3