[3.16.y-ckt stable] Patch "md: Always set RECOVERY_NEEDED when clearing RECOVERY_FROZEN" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    md: Always set RECOVERY_NEEDED when clearing RECOVERY_FROZEN

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 2831db47e07bed6597b45615c126e26bfc578a20 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb at suse.de>
Date: Wed, 29 Oct 2014 08:49:50 +1100
Subject: md: Always set RECOVERY_NEEDED when clearing RECOVERY_FROZEN

commit 45eaf45dfa4850df16bc2e8e7903d89021137f40 upstream.

md_check_recovery will skip any recovery and also clear
MD_RECOVERY_NEEDED if MD_RECOVERY_FROZEN is set.
So when we clear _FROZEN, we must set _NEEDED and ensure that
md_check_recovery gets run.
Otherwise we could miss out on something that is needed.

In particular, this can make it impossible to remove a
failed device from an array is the  'recovery-needed' processing
didn't happen.
Suitable for stable kernels since 3.13.

Reported-and-tested-by: Joe Lawrence <joe.lawrence at stratus.com>
Fixes: 30b8feb730f9b9b3c5de02580897da03f59b6b16
Signed-off-by: NeilBrown <neilb at suse.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/md/md.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 32fc19c540d4..f5b1af403b5c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5313,6 +5313,7 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
 		printk("md: %s still in use.\n",mdname(mddev));
 		if (did_freeze) {
 			clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 			md_wakeup_thread(mddev->thread);
 		}
 		err = -EBUSY;
@@ -5327,6 +5328,8 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
 		mddev->ro = 1;
 		set_disk_ro(mddev->gendisk, 1);
 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+		md_wakeup_thread(mddev->thread);
 		sysfs_notify_dirent_safe(mddev->sysfs_state);
 		err = 0;
 	}
@@ -5370,6 +5373,7 @@ static int do_md_stop(struct mddev * mddev, int mode,
 		mutex_unlock(&mddev->open_mutex);
 		if (did_freeze) {
 			clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 			md_wakeup_thread(mddev->thread);
 		}
 		return -EBUSY;
--
2.1.0