[PATCH AUTOSEL 4.19 002/100] f2fs: flush quota blocks after turnning it off

[Sasha Levin]

From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

[ Upstream commit 0e0667b625cf64243df83171bff61f9d350b9ca5 ]

After quota_off, we'll get some dirty blocks. If put_super don't have a chance
to flush them by checkpoint, it causes NULL pointer exception in end_io after
iput(node_inode). (e.g., by checkpoint=disable)

Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/f2fs/super.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index fdafcfd8b20e2..4ec57d538c15c 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1886,6 +1886,12 @@ void f2fs_quota_off_umount(struct super_block *sb)
 			set_sbi_flag(F2FS_SB(sb), SBI_NEED_FSCK);
 		}
 	}
+	/*
+	 * In case of checkpoint=disable, we must flush quota blocks.
+	 * This can cause NULL exception for node_inode in end_io, since
+	 * put_super already dropped it.
+	 */
+	sync_filesystem(sb);
 }
 
 static void f2fs_truncate_quota_inode_pages(struct super_block *sb)
-- 
2.20.1