From: Tejun Heo <tj@kernel.org> 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@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/fs-writeback.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 027e50419f17..fe1604ad9023 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -269,6 +269,7 @@ void __inode_attach_wb(struct inode *inode, struct page *page) 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 -- 2.25.1