btrfs: sysfs: introduce helper for syncing bits with sysfs files
The files under /sys/fs/UUID/features get out of sync with the actual
incompat bits set for the filesystem if they change after mount. We're
going to sync them and need a helper to do that.
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 906f7ed..6986886 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -782,6 +782,36 @@
return error;
}
+
+/*
+ * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
+ * values in superblock. Call after any changes to incompat/compat_ro flags
+ */
+void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
+ u64 bit, enum btrfs_feature_set set)
+{
+ struct btrfs_fs_devices *fs_devs;
+ struct kobject *fsid_kobj;
+ u64 features;
+ int ret;
+
+ if (!fs_info)
+ return;
+
+ features = get_features(fs_info, set);
+ ASSERT(bit & supported_feature_masks[set]);
+
+ fs_devs = fs_info->fs_devices;
+ fsid_kobj = &fs_devs->fsid_kobj;
+
+ /*
+ * FIXME: this is too heavy to update just one value, ideally we'd like
+ * to use sysfs_update_group but some refactoring is needed first.
+ */
+ sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
+ ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
+}
+
static int btrfs_init_debugfs(void)
{
#ifdef CONFIG_DEBUG_FS