befs: add flags field to validate superblock state

For validating superblock state, add flags field to befs_sb_info, read the state from the disk
and check if it is equal to BEFS_DIRTY.
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>

fs/befs/befs.h

@@ -43,6 +43,9 @@ struct befs_sb_info {
 	u32 ag_shift;
 	u32 num_ags;
 
+	/* State of the superblock */
+	u32 flags;
+
 	/* jornal log entry */
 	befs_block_run log_blocks;
 	befs_off_t log_start;

fs/befs/super.c

@@ -45,6 +45,8 @@ befs_load_sb(struct super_block *sb, befs_super_block * disk_sb)
 	befs_sb->ag_shift = fs32_to_cpu(sb, disk_sb->ag_shift);
 	befs_sb->num_ags = fs32_to_cpu(sb, disk_sb->num_ags);
 
+	befs_sb->flags = fs32_to_cpu(sb, disk_sb->flags);
+
 	befs_sb->log_blocks = fsrun_to_cpu(sb, disk_sb->log_blocks);
 	befs_sb->log_start = fs64_to_cpu(sb, disk_sb->log_start);
 	befs_sb->log_end = fs64_to_cpu(sb, disk_sb->log_end);
@@ -101,7 +103,7 @@ befs_check_sb(struct super_block *sb)
 		return BEFS_ERR;
 	}
 
-	if (befs_sb->log_start != befs_sb->log_end) {
+	if (befs_sb->log_start != befs_sb->log_end || befs_sb->flags == BEFS_DIRTY) {
 		befs_error(sb, "Filesystem not clean! There are blocks in the "
 			   "journal. You must boot into BeOS and mount this volume "
 			   "to make it clean.");