[PATCH] md: expose md metadata format in sysfs

Allow it to be set to a particular version, or 'none'.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
NeilBrown 2006-01-06 00:20:50 -08:00 committed by Linus Torvalds
parent a35b0d695d
commit 8bb93aaca2
2 changed files with 55 additions and 0 deletions

View File

@ -183,6 +183,12 @@ All md devices contain:
the array if the personality supports it (raid1, raid5, raid6),
and if the component drives are large enough.
metadata_version
This indicates the format that is being used to record metadata
about the array. It can be 0.90 (traditional format), 1.0, 1.1,
1.2 (newer format in varying locations) or "none" indicating that
the kernel isn't managing metadata at all.
As component devices are added to an md array, they appear in the 'md'
directory as new directories named
dev-XXX

View File

@ -1857,6 +1857,54 @@ size_store(mddev_t *mddev, const char *buf, size_t len)
static struct md_sysfs_entry md_size =
__ATTR(component_size, 0644, size_show, size_store);
/* Metdata version.
* This is either 'none' for arrays with externally managed metadata,
* or N.M for internally known formats
*/
static ssize_t
metadata_show(mddev_t *mddev, char *page)
{
if (mddev->persistent)
return sprintf(page, "%d.%d\n",
mddev->major_version, mddev->minor_version);
else
return sprintf(page, "none\n");
}
static ssize_t
metadata_store(mddev_t *mddev, const char *buf, size_t len)
{
int major, minor;
char *e;
if (!list_empty(&mddev->disks))
return -EBUSY;
if (cmd_match(buf, "none")) {
mddev->persistent = 0;
mddev->major_version = 0;
mddev->minor_version = 90;
return len;
}
major = simple_strtoul(buf, &e, 10);
if (e==buf || *e != '.')
return -EINVAL;
buf = e+1;
minor = simple_strtoul(buf, &e, 10);
if (e==buf || *e != '\n')
return -EINVAL;
if (major >= sizeof(super_types)/sizeof(super_types[0]) ||
super_types[major].name == NULL)
return -ENOENT;
mddev->major_version = major;
mddev->minor_version = minor;
mddev->persistent = 1;
return len;
}
static struct md_sysfs_entry md_metadata =
__ATTR(metadata_version, 0644, metadata_show, metadata_store);
static ssize_t
action_show(mddev_t *mddev, char *page)
{
@ -1926,6 +1974,7 @@ static struct attribute *md_default_attrs[] = {
&md_raid_disks.attr,
&md_chunk_size.attr,
&md_size.attr,
&md_metadata.attr,
NULL,
};