From: Tejun Heo <tj@xxxxxxxxxx> commit 9b0eb69b75bccada2d341d7e7ca342f0cb1c9a6a upstream. btrfs is going to use css_put() and wbc helpers to improve cgroup writeback support. Add dummy css_get() definition and export wbc helpers to prepare for module and !CONFIG_CGROUP builds. [only backport the export of __inode_attach_wb for stable kernels - gregkh] Reported-by: kbuild test robot <lkp@xxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/fs-writeback.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -269,6 +269,7 @@ void __inode_attach_wb(struct inode *ino if (unlikely(cmpxchg(&inode->i_wb, NULL, wb))) wb_put(wb); } +EXPORT_SYMBOL_GPL(__inode_attach_wb); /** * locked_inode_to_wb_and_lock_list - determine a locked inode's wb and lock it
