diff options
| -rw-r--r-- | Documentation/md.txt | 6 | ||||
| -rw-r--r-- | drivers/md/md.c | 49 |
2 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt index 0a2e10a4040d..c5512afd5917 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -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 --git a/drivers/md/md.c b/drivers/md/md.c index d568ab4a487f..ecc0166ba779 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -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, }; |