[PATCH 1/2] exfat: call sync_filesystem for read-only remount

[Hyunchul Lee]

We need to commit dirty metadata and pages to disk
before remounting exfat as read-only.

This fixes a failure in xfstests generic/452

Signed-off-by: Hyunchul Lee <hyc....@gmail.com>
---
 fs/exfat/super.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index e650e65536f8..61c6cf240c19 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -693,10 +693,29 @@ static void exfat_free(struct fs_context *fc)
        }
 }
 
+static int exfat_reconfigure(struct fs_context *fc)
+{
+       struct super_block *sb = fc->root->d_sb;
+       int ret;
+       bool new_rdonly;
+
+       new_rdonly = fc->sb_flags & SB_RDONLY;
+       if (new_rdonly != sb_rdonly(sb)) {
+               if (new_rdonly) {
+                       /* volume flag will be updated in exfat_sync_fs */
+                       ret = sync_filesystem(sb);
+                       if (ret < 0)
+                               return ret;
+               }
+       }
+       return 0;
+}
+
 static const struct fs_context_operations exfat_context_ops = {
        .parse_param    = exfat_parse_param,
        .get_tree       = exfat_get_tree,
        .free           = exfat_free,
+       .reconfigure    = exfat_reconfigure,
 };
 
 static int exfat_init_fs_context(struct fs_context *fc)
-- 
2.17.1