f2fs: flush quota blocks after turnning it off

BugLink: https://bugs.launchpad.net/bugs/1852492
[ 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@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index ff2e512f5e7030248a64b781df692b840555eb71..0c7abc5b13f21b0082bb6c1e3caf1fc1771a302d 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1667,6 +1667,12 @@ 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)