This is a note to let you know that I've just added the patch titled
md: don't set md arrays to readonly on shutdown.
to the 3.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
md-don-t-set-md-arrays-to-readonly-on-shutdown.patch
and it can be found in the queue-3.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From c744a65c1e2d59acc54333ce80a5b0702a98010b Mon Sep 17 00:00:00 2001
From: NeilBrown <[email protected]>
Date: Mon, 19 Mar 2012 12:46:37 +1100
Subject: md: don't set md arrays to readonly on shutdown.
From: NeilBrown <[email protected]>
commit c744a65c1e2d59acc54333ce80a5b0702a98010b upstream.
It seems that with recent kernel, writeback can still be happening
while shutdown is happening, and consequently data can be written
after the md reboot notifier switches all arrays to read-only.
This causes a BUG.
So don't switch them to read-only - just mark them clean and
set 'safemode' to '2' which mean that immediately after any
write the array will be switch back to 'clean'.
This could result in the shutdown happening when array is marked
dirty, thus forcing a resync on reboot. However if you reboot
without performing a "sync" first, you get to keep both halves.
This is suitable for any stable kernel (though there might be some
conflicts with obvious fixes in earlier kernels).
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/md/md.c | 37 +++++++++++++++----------------------
1 file changed, 15 insertions(+), 22 deletions(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8097,30 +8097,23 @@ static int md_notify_reboot(struct notif
struct mddev *mddev;
int need_delay = 0;
- if ((code == SYS_DOWN) || (code == SYS_HALT) || (code ==
SYS_POWER_OFF)) {
-
- printk(KERN_INFO "md: stopping all md devices.\n");
-
- for_each_mddev(mddev, tmp) {
- if (mddev_trylock(mddev)) {
- /* Force a switch to readonly even array
- * appears to still be in use. Hence
- * the '100'.
- */
- md_set_readonly(mddev, 100);
- mddev_unlock(mddev);
- }
- need_delay = 1;
+ for_each_mddev(mddev, tmp) {
+ if (mddev_trylock(mddev)) {
+ __md_stop_writes(mddev);
+ mddev->safemode = 2;
+ mddev_unlock(mddev);
}
- /*
- * certain more exotic SCSI devices are known to be
- * volatile wrt too early system reboots. While the
- * right place to handle this issue is the given
- * driver, we do want to have a safe RAID driver ...
- */
- if (need_delay)
- mdelay(1000*1);
+ need_delay = 1;
}
+ /*
+ * certain more exotic SCSI devices are known to be
+ * volatile wrt too early system reboots. While the
+ * right place to handle this issue is the given
+ * driver, we do want to have a safe RAID driver ...
+ */
+ if (need_delay)
+ mdelay(1000*1);
+
return NOTIFY_DONE;
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.2/md-raid1-raid10-avoid-deadlock-during-resync-recovery.patch
queue-3.2/md-bitmap-ensure-to-load-bitmap-when-creating-via-sysfs.patch
queue-3.2/md-fix-clearing-of-the-changed-flags-for-the-bad-blocks-list.patch
queue-3.2/md-don-t-set-md-arrays-to-readonly-on-shutdown.patch
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