From ea43ddd8491feccf36267349748ea91b1194481e Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Mon, 13 Oct 2008 11:55:11 +1100
Subject: [PATCH] md: Allow metadata_version to be updated for externally
managed metadata.
For externally managed metadata, the 'metadata_version' sysfs
attribute is really just a channel for user-space programs to
communicate about how the array is being managed.
It can be useful for this to be changed while the array is active.
Normally changes to metadata_version are not permitted while the array
is active. Change that so that if the metadata is externally managed,
the metadata_version can be changed to a different flavour of external
management.
Signed-off-by: NeilBrown <neilb@suse.de>
---
drivers/md/md.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 7d8c2bb0a67c..13dd7b276150 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2943,7 +2943,13 @@ metadata_store(mddev_t *mddev, const char *buf, size_t len)
{
int major, minor;
char *e;
- if (!list_empty(&mddev->disks))
+ /* Changing the details of 'external' metadata is
+ * always permitted. Otherwise there must be
+ * no devices attached to the array.
+ */
+ if (mddev->external && strncmp(buf, "external:", 9) == 0)
+ ;
+ else if (!list_empty(&mddev->disks))
return -EBUSY;
if (cmd_match(buf, "none")) {
--
2.30.9