[LogFS] Check feature flags

diff --git a/fs/logfs/logfs_abi.h b/fs/logfs/logfs_abi.h
index 5d3782d..8d4dd3d 100644 (file)
--- 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 1d081b7..c66beab 100644 (file)
--- 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;