linux-kernel - [PATCH 4.14 049/122] md: allow metadata updates while suspending an array

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191122100757.092527726@linuxfoundation.org>
Date:   Fri, 22 Nov 2019 11:28:22 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Jeff Mahoney <jeffm@...e.com>,
        NeilBrown <neilb@...e.com>, Shaohua Li <shli@...com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.14 049/122] md: allow metadata updates while suspending an array - fix

From: NeilBrown <neilb@...e.com>

[ Upstream commit 059421e041eb461fb2b3e81c9adaec18ef03ca3c ]

Commit 35bfc52187f6 ("md: allow metadata update while suspending.")
added support for allowing md_check_recovery() to still perform
metadata updates while the array is entering the 'suspended' state.
This is needed to allow the processes of entering the state to
complete.

Unfortunately, the patch doesn't really work.  The test for
"mddev->suspended" at the start of md_check_recovery() means that the
function doesn't try to do anything at all while entering suspend.

This patch moves the code of updating the metadata while suspending to
*before* the test on mddev->suspended.

Reported-by: Jeff Mahoney <jeffm@...e.com>
Fixes: 35bfc52187f6 ("md: allow metadata update while suspending.")
Signed-off-by: NeilBrown <neilb@...e.com>
Signed-off-by: Shaohua Li <shli@...com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/md/md.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index e529cef5483a8..b942c74f1ce83 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8736,6 +8736,18 @@ static void md_start_sync(struct work_struct *ws)
  */
 void md_check_recovery(struct mddev *mddev)
 {
+	if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags) && mddev->sb_flags) {
+		/* Write superblock - thread that called mddev_suspend()
+		 * holds reconfig_mutex for us.
+		 */
+		set_bit(MD_UPDATING_SB, &mddev->flags);
+		smp_mb__after_atomic();
+		if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags))
+			md_update_sb(mddev, 0);
+		clear_bit_unlock(MD_UPDATING_SB, &mddev->flags);
+		wake_up(&mddev->sb_wait);
+	}
+
 	if (mddev->suspended)
 		return;
 
@@ -8896,16 +8908,6 @@ void md_check_recovery(struct mddev *mddev)
 	unlock:
 		wake_up(&mddev->sb_wait);
 		mddev_unlock(mddev);
-	} else if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags) && mddev->sb_flags) {
-		/* Write superblock - thread that called mddev_suspend()
-		 * holds reconfig_mutex for us.
-		 */
-		set_bit(MD_UPDATING_SB, &mddev->flags);
-		smp_mb__after_atomic();
-		if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags))
-			md_update_sb(mddev, 0);
-		clear_bit_unlock(MD_UPDATING_SB, &mddev->flags);
-		wake_up(&mddev->sb_wait);
 	}
 }
 EXPORT_SYMBOL(md_check_recovery);
-- 
2.20.1