Allow it to be set to a particular version, or 'none'.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
### Diffstat output
./Documentation/md.txt | 6 ++++++
./drivers/md/md.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)
diff ./Documentation/md.txt~current~ ./Documentation/md.txt
--- ./Documentation/md.txt~current~ 2005-12-12 11:31:46.000000000 +1100
+++ ./Documentation/md.txt 2005-12-12 11:33:02.000000000 +1100
@@ -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
diff ./drivers/md/md.c~current~ ./drivers/md/md.c
--- ./drivers/md/md.c~current~ 2005-12-12 11:32:28.000000000 +1100
+++ ./drivers/md/md.c 2005-12-12 11:33:24.000000000 +1100
@@ -1857,6 +1857,54 @@ size_store(mddev_t *mddev, const char *b
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_attr
&md_raid_disks.attr,
&md_chunk_size.attr,
&md_size.attr,
+ &md_metadata.attr,
NULL,
};
-
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