nilfs2: reject incompatible filesystem

This forces nilfs to check compatibility of feature flags so as to
reject a filesystem with unknown features when it mounts or remounts
the filesystem.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index cfedc48d78d9..0842d775b3e0 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -275,6 +275,8 @@ extern struct nilfs_super_block *
 nilfs_read_super_block(struct super_block *, u64, int, struct buffer_head **);
 extern int nilfs_store_magic_and_option(struct super_block *,
                                         struct nilfs_super_block *, char *);
+extern int nilfs_check_feature_compatibility(struct super_block *,
+                                             struct nilfs_super_block *);
 extern void nilfs_set_log_cursor(struct nilfs_super_block *,
                                  struct the_nilfs *);
 extern struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *,