4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: NeilBrown <neilb@xxxxxxxx>
commit d47c8ad261f787af22a220ffcc2d07afba809223 upstream.
A recent patch aimed to cause md_write_start() to fail (rather than
block) when the mddev was suspending, so as to avoid deadlocks.
Unfortunately the test in wait_event() was wrong, and it didn't change
behaviour at all.
We wait_event() must wait until the metadata is written OR the array is
suspending.
Fixes: cc27b0c78c79 ("md: fix deadlock between mddev_suspend() and md_write_start()")
Reported-by: Xiao Ni <xni@xxxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Shaohua Li <shli@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/md.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8039,7 +8039,8 @@ bool md_write_start(struct mddev *mddev,
if (did_change)
sysfs_notify_dirent_safe(mddev->sysfs_state);
wait_event(mddev->sb_wait,
- !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) && !mddev->suspended);
+ !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) ||
+ mddev->suspended);
if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
percpu_ref_put(&mddev->writes_pending);
return false;