[PATCH] md: allow md/raid_disks to be settable
If array is active, try to reshape, else just set the value.
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>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 32a4e23..86e9f2e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1843,7 +1843,27 @@
return sprintf(page, "%d\n", mddev->raid_disks);
}
-static struct md_sysfs_entry md_raid_disks = __ATTR_RO(raid_disks);
+static int update_raid_disks(mddev_t *mddev, int raid_disks);
+
+static ssize_t
+raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
+{
+ /* can only set raid_disks if array is not yet active */
+ char *e;
+ int rv = 0;
+ unsigned long n = simple_strtoul(buf, &e, 10);
+
+ if (!*buf || (*e && *e != '\n'))
+ return -EINVAL;
+
+ if (mddev->pers)
+ rv = update_raid_disks(mddev, n);
+ else
+ mddev->raid_disks = n;
+ return rv ? rv : len;
+}
+static struct md_sysfs_entry md_raid_disks =
+__ATTR(raid_disks, 0644, raid_disks_show, raid_disks_store);
static ssize_t
chunk_size_show(mddev_t *mddev, char *page)
@@ -3201,6 +3221,33 @@
return rv;
}
+static int update_raid_disks(mddev_t *mddev, int raid_disks)
+{
+ int rv;
+ /* change the number of raid disks */
+ if (mddev->pers->reshape == NULL)
+ return -EINVAL;
+ if (raid_disks <= 0 ||
+ raid_disks >= mddev->max_disks)
+ return -EINVAL;
+ if (mddev->sync_thread)
+ return -EBUSY;
+ rv = mddev->pers->reshape(mddev, raid_disks);
+ if (!rv) {
+ struct block_device *bdev;
+
+ bdev = bdget_disk(mddev->gendisk, 0);
+ if (bdev) {
+ down(&bdev->bd_inode->i_sem);
+ i_size_write(bdev->bd_inode, mddev->array_size << 10);
+ up(&bdev->bd_inode->i_sem);
+ bdput(bdev);
+ }
+ }
+ return rv;
+}
+
+
/*
* update_array_info is used to change the configuration of an
* on-line array.
@@ -3252,28 +3299,9 @@
if (mddev->size != info->size)
rv = update_size(mddev, info->size);
- if (mddev->raid_disks != info->raid_disks) {
- /* change the number of raid disks */
- if (mddev->pers->reshape == NULL)
- return -EINVAL;
- if (info->raid_disks <= 0 ||
- info->raid_disks >= mddev->max_disks)
- return -EINVAL;
- if (mddev->sync_thread)
- return -EBUSY;
- rv = mddev->pers->reshape(mddev, info->raid_disks);
- if (!rv) {
- struct block_device *bdev;
+ if (mddev->raid_disks != info->raid_disks)
+ rv = update_raid_disks(mddev, info->raid_disks);
- bdev = bdget_disk(mddev->gendisk, 0);
- if (bdev) {
- down(&bdev->bd_inode->i_sem);
- i_size_write(bdev->bd_inode, mddev->array_size << 10);
- up(&bdev->bd_inode->i_sem);
- bdput(bdev);
- }
- }
- }
if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
if (mddev->pers->quiesce == NULL)
return -EINVAL;