[PATCH 4.19 041/267] cgroup, blkcg: Prepare some symbols for module and !CONFIG_CGROUP usages

Greg Kroah-Hartman
2020-06-19T14:54:57Z

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>

---
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