diff options
| -rw-r--r-- | Documentation/md.txt | 5 | ||||
| -rw-r--r-- | drivers/md/md.c | 27 |
2 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt index 4cf5972821a..80f158745ca 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -200,6 +200,11 @@ All md devices contain: This can be written only while the array is being assembled, not after it is started. + layout + The "layout" for the array for the particular level. This is + simply a number that is interpretted differently by different + levels. It can be written while assembling an array. + new_dev This file can be written but not read. The value written should be a block device number as major:minor. e.g. 8:0 diff --git a/drivers/md/md.c b/drivers/md/md.c index 4b74c77213c..e3261c438a6 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2155,6 +2155,32 @@ level_store(mddev_t *mddev, const char *buf, size_t len) static struct md_sysfs_entry md_level = __ATTR(level, 0644, level_show, level_store); + +static ssize_t +layout_show(mddev_t *mddev, char *page) +{ + /* just a number, not meaningful for all levels */ + return sprintf(page, "%d\n", mddev->layout); +} + +static ssize_t +layout_store(mddev_t *mddev, const char *buf, size_t len) +{ + char *e; + unsigned long n = simple_strtoul(buf, &e, 10); + if (mddev->pers) + return -EBUSY; + + if (!*buf || (*e && *e != '\n')) + return -EINVAL; + + mddev->layout = n; + return len; +} +static struct md_sysfs_entry md_layout = +__ATTR(layout, 0655, layout_show, layout_store); + + static ssize_t raid_disks_show(mddev_t *mddev, char *page) { @@ -2741,6 +2767,7 @@ __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store); static struct attribute *md_default_attrs[] = { &md_level.attr, + &md_layout.attr, &md_raid_disks.attr, &md_chunk_size.attr, &md_size.attr, |