f2fs: fix lost xattrs of directories

This patch enhances the xattr consistency of dirs from suddern power-cuts.

Possible scenario would be:
1. dir->setxattr used by per-file encryption
2. file->setxattr goes into inline_xattr
3. file->fsync

In that case, we should do checkpoint for #1.
Otherwise we'd lose dir's key information for the file given #2.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c2478a1..b9611d4 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -756,6 +756,7 @@
 	SBI_NEED_FSCK,				/* need fsck.f2fs to fix */
 	SBI_POR_DOING,				/* recovery is doing or not */
 	SBI_NEED_SB_WRITE,			/* need to recover superblock */
+	SBI_NEED_CP,				/* need to checkpoint */
 };
 
 enum {