+/*
+ * update_array_info is used to change the configuration of an
+ * on-line array.
+ * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
+ * fields in the info are checked against the array.
+ * Any differences that cannot be handled will cause an error.
+ * Normally, only one change can be managed at a time.
+ */
+static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
+{
+ int rv = 0;
+ int cnt = 0;
+
+ if (mddev->major_version != info->major_version ||
+ mddev->minor_version != info->minor_version ||
+/* mddev->patch_version != info->patch_version || */
+ mddev->ctime != info->ctime ||
+ mddev->level != info->level ||
+/* mddev->layout != info->layout || */
+ !mddev->persistent != info->not_persistent||
+ mddev->chunk_size != info->chunk_size )
+ return -EINVAL;
+ /* Check there is only one change */
+ if (mddev->size != info->size) cnt++;
+ if (mddev->raid_disks != info->raid_disks) cnt++;
+ if (mddev->layout != info->layout) cnt++;
+ if (cnt == 0) return 0;
+ if (cnt > 1) return -EINVAL;
+
+ if (mddev->layout != info->layout) {
+ /* Change layout
+ * we don't need to do anything at the md level, the
+ * personality will take care of it all.
+ */
+ if (mddev->pers->reconfig == NULL)
+ return -EINVAL;
+ else
+ return mddev->pers->reconfig(mddev, info->layout, -1);
+ }
+ if (mddev->size != info->size) {
+ mdk_rdev_t * rdev;
+ struct list_head *tmp;
+ if (mddev->pers->resize == NULL)
+ return -EINVAL;
+ /* The "size" is the amount of each device that is used.
+ * This can only make sense for arrays with redundancy.
+ * linear and raid0 always use whatever space is available
+ * We can only consider changing the size if no resync
+ * or reconstruction is happening, and if the new size
+ * is acceptable. It must fit before the sb_offset or,
+ * if that is <data_offset, it must fit before the
+ * size of each device.
+ * If size is zero, we find the largest size that fits.
+ */
+ if (mddev->sync_thread)
+ return -EBUSY;
+ ITERATE_RDEV(mddev,rdev,tmp) {
+ sector_t avail;
+ int fit = (info->size == 0);
+ if (rdev->sb_offset > rdev->data_offset)
+ avail = (rdev->sb_offset*2) - rdev->data_offset;
+ else
+ avail = get_capacity(rdev->bdev->bd_disk)
+ - rdev->data_offset;
+ if (fit && (info->size == 0 || info->size > avail/2))
+ info->size = avail/2;
+ if (avail < ((sector_t)info->size << 1))
+ return -ENOSPC;
+ }
+ rv = mddev->pers->resize(mddev, (sector_t)info->size *2);
+ 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);
+ }
+ }
+ }
+ 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;
+
+ 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);
+ }
+ }
+ }
+ md_update_sb(mddev);
+ return rv;
+}
+