Commit d87f064f authored Apr 24, 2013 by NeilBrown

md: never update metadata when array is read-only.



Normally we don't even try to update the metadata if
the array is read-only.  However future patches
will increase the number of things that can happen on a read-only
array, so it is safest to explicitly disable this.

Every time that mddev->ro is set to 0, either
 - md_update_sb will be called again (at least if MD_CHANGE_DEVS
   is set) or
 - the mddev->thread is scheduled, which will also run
   md_update_sb if needed.

So this is safe: if the array ever become read-write the
metadata will be updated.

Signed-off-by: NeilBrown <neilb@suse.de>

parent 824282ca

drivers/md/md.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -2411,6 +2411,11 @@ static void md_update_sb(struct mddev * mddev, int force_change)
		int nospares = 0;
		int any_badblocks_changed = 0;

		if (mddev->ro) {
		if (force_change)
		set_bit(MD_CHANGE_DEVS, &mddev->flags);
		return;
		}
		repeat:
		/* First make sure individual recovery_offsets are correct */
		rdev_for_each(rdev, mddev) {

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