+ ret = mnt_want_write(filp->f_path.mnt);
+ if (ret)
+ return ret;
+ if (get_user(inode->i_generation, (int __user *) arg)) {
+ ret = -EFAULT;
+ } else {
+ inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty(inode);
+ }
+ mnt_drop_write(filp->f_path.mnt);
+ return ret;
+ case EXT2_IOC_GETRSVSZ:
+ if (test_opt(inode->i_sb, RESERVATION)
+ && S_ISREG(inode->i_mode)
+ && ei->i_block_alloc_info) {
+ rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
+ return put_user(rsv_window_size, (int __user *)arg);
+ }
+ return -ENOTTY;
+ case EXT2_IOC_SETRSVSZ: {
+
+ if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
+ return -ENOTTY;
+
+ if (!is_owner_or_cap(inode))
+ return -EACCES;
+
+ if (get_user(rsv_window_size, (int __user *)arg))
+ return -EFAULT;
+
+ ret = mnt_want_write(filp->f_path.mnt);
+ if (ret)
+ return ret;
+
+ if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
+ rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
+
+ /*
+ * need to allocate reservation structure for this inode
+ * before set the window size
+ */
+ /*
+ * XXX What lock should protect the rsv_goal_size?
+ * Accessed in ext2_get_block only. ext3 uses i_truncate.
+ */
+ mutex_lock(&ei->truncate_mutex);
+ if (!ei->i_block_alloc_info)
+ ext2_init_block_alloc_info(inode);
+
+ if (ei->i_block_alloc_info){
+ struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
+ rsv->rsv_goal_size = rsv_window_size;
+ }
+ mutex_unlock(&ei->truncate_mutex);
+ mnt_drop_write(filp->f_path.mnt);