[LogFS] Check feature flags

2 files changed, 12 insertions, 2 deletions

diff --git a/fs/logfs/logfs_abi.h b/fs/logfs/logfs_abi.h
index 5d3782ddecc8..8d4dd3de551e 100644
--- a/fs/logfs/logfs_abi.h
+++ b/fs/logfs/logfs_abi.h
@@ -193,6 +193,10 @@ struct logfs_segment_header {
 
 SIZE_CHECK(logfs_segment_header, LOGFS_SEGMENT_HEADERSIZE);
 
+#define LOGFS_FEATURES_INCOMPAT         (0ull)
+#define LOGFS_FEATURES_RO_COMPAT        (0ull)
+#define LOGFS_FEATURES_COMPAT           (0ull)
+
 /**
  * struct logfs_disk_super - on-medium superblock
  *
diff --git a/fs/logfs/super.c b/fs/logfs/super.c
index 1d081b7ede5a..c66beab78dee 100644
--- a/fs/logfs/super.c
+++ b/fs/logfs/super.c
@@ -440,7 +440,7 @@ static int __logfs_read_sb(struct super_block *sb)
         return 0;
 }
 
-static int logfs_read_sb(struct super_block *sb)
+static int logfs_read_sb(struct super_block *sb, int read_only)
 {
         struct logfs_super *super = logfs_super(sb);
         int ret;
@@ -460,6 +460,12 @@ static int logfs_read_sb(struct super_block *sb)
         if (ret)
                 return ret;
 
+        if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT)
+                return -EIO;
+        if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) &&
+                        !read_only)
+                return -EIO;
+
         mutex_init(&super->s_dirop_mutex);
         mutex_init(&super->s_object_alias_mutex);
         INIT_LIST_HEAD(&super->s_freeing_list);
@@ -555,7 +561,7 @@ int logfs_get_sb_device(struct file_system_type *type, int flags,
         sb->s_op        = &logfs_super_operations;
         sb->s_flags     = flags | MS_NOATIME;
 
-        err = logfs_read_sb(sb);
+        err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY);
         if (err)
                 goto err1;