int is_dead_root = 0;
/*
- * this is an orphan in the tree root. Currently these
+ * This is an orphan in the tree root. Currently these
* could come from 2 sources:
- * a) a snapshot deletion in progress
+ * a) a root (snapshot/subvolume) deletion in progress
* b) a free space cache inode
- * We need to distinguish those two, as the snapshot
- * orphan must not get deleted.
- * find_dead_roots already ran before us, so if this
- * is a snapshot deletion, we should find the root
- * in the fs_roots radix tree.
+ * We need to distinguish those two, as the orphan item
+ * for a root must not get deleted before the deletion
+ * of the snapshot/subvolume's tree completes.
+ *
+ * btrfs_find_orphan_roots() ran before us, which has
+ * found all deleted roots and loaded them into
+ * fs_info->fs_roots_radix. So here we can find if an
+ * orphan item corresponds to a deleted root by looking
+ * up the root from that radix tree.
*/
spin_lock(&fs_info->fs_roots_radix_lock);