This is a note to let you know that I've just added the patch titled

md: fix deadlock error in recent patch.

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: md-fix-deadlock-error-in-recent-patch.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From d47c8ad261f787af22a220ffcc2d07afba809223 Mon Sep 17 00:00:00 2001

From: NeilBrown neilb@suse.com Date: Thu, 5 Oct 2017 16:23:16 +1100 Subject: md: fix deadlock error in recent patch.

From: NeilBrown neilb@suse.com

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@redhat.com Signed-off-by: NeilBrown neilb@suse.com Signed-off-by: Shaohua Li shli@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- 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;

Patches currently in stable-queue which might be from neilb@suse.com are

queue-4.14/md-fix-deadlock-error-in-recent-patch.patch queue-4.14/autofs-don-t-fail-mount-for-transient-error.patch queue-4.14/md-bitmap-revert-a-patch.patch queue-4.14/nfs-revalidate-.-etc-correctly-on-open.patch