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/checkpoint.c b/fs/f2fs/checkpoint.c
index 64a685d..727e97e 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1152,6 +1152,7 @@
 
 	clear_prefree_segments(sbi, cpc);
 	clear_sbi_flag(sbi, SBI_IS_DIRTY);
+	clear_sbi_flag(sbi, SBI_NEED_CP);
 
 	return 0;
 }
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 {
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 7c6ee7e..21aa99b 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -135,6 +135,8 @@
 
 	if (!S_ISREG(inode->i_mode) || inode->i_nlink != 1)
 		need_cp = true;
+	else if (is_sbi_flag_set(sbi, SBI_NEED_CP))
+		need_cp = true;
 	else if (file_enc_name(inode) && need_dentry_mark(sbi, inode->i_ino))
 		need_cp = true;
 	else if (file_wrong_pino(inode))
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index c8898b5..d39a792 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -548,6 +548,8 @@
 			!strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT))
 		f2fs_set_encrypted_inode(inode);
 	f2fs_mark_inode_dirty_sync(inode);
+	if (!error && S_ISDIR(inode->i_mode))
+		set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP);
 exit:
 	kzfree(base_addr);
 	return error;