Btrfs: set a compat flag when setting default subvol

Commit Message

Josef Bacik Dec. 17, 2009, 9:40 p.m. UTC

None

Patch

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 917211b..fa8a3e7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -371,7 +371,10 @@  struct btrfs_super_block {
  */
 #define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF	(1ULL << 0)
 
-#define BTRFS_FEATURE_COMPAT_SUPP		0ULL
+#define BTRFS_FEATURE_COMPAT_DEFAULT_SUBVOL	(1ULL << 0)
+
+#define BTRFS_FEATURE_COMPAT_SUPP		\
+	BTRFS_FEATURE_COMPAT_DEFAULT_SUBVOL
 #define BTRFS_FEATURE_COMPAT_RO_SUPP		0ULL
 #define BTRFS_FEATURE_INCOMPAT_SUPP		\
 	BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 81d8378..6a78711 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1563,6 +1563,8 @@  static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	struct btrfs_path *path;
 	struct btrfs_key location;
 	struct btrfs_disk_key disk_key;
+	struct btrfs_super_block *disk_super;
+	u64 features;
 	u64 objectid = 0;
 	u64 dir_id;
 
@@ -1610,6 +1612,12 @@  static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 	btrfs_free_path(path);
 
+	disk_super = &root->fs_info->super_copy;
+	features = btrfs_super_compat_flags(disk_super);
+	if (!(features & BTRFS_FEATURE_COMPAT_DEFAULT_SUBVOL)) {
+		features |= BTRFS_FEATURE_COMPAT_DEFAULT_SUBVOL;
+		btrfs_set_super_compat_flags(disk_super, features);
+	}
 	btrfs_end_transaction(trans, root);
 
 	return 0;