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>
This commit is contained in:
NeilBrown 2008-10-13 11:55:11 +11:00
parent 7d3c6f8717
commit ea43ddd849

View File

@ -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")) {