diff options
Diffstat (limited to 'fs/btrfs/ctree.h')
| -rw-r--r-- | fs/btrfs/ctree.h | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 0a1fa1526c43..bf46093be76e 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -969,7 +969,28 @@ enum { * is used to tell us when more checks are required */ BTRFS_ROOT_IN_TRANS_SETUP, - BTRFS_ROOT_REF_COWS, + + /* + * Set if tree blocks of this root can be shared by other roots. + * Only subvolume trees and their reloc trees have this bit set. + * Conflicts with TRACK_DIRTY bit. + * + * This affects two things: + * + * - How balance works + * For shareable roots, we need to use reloc tree and do path + * replacement for balance, and need various pre/post hooks for + * snapshot creation to handle them. + * + * While for non-shareable trees, we just simply do a tree search + * with COW. + * + * - How dirty roots are tracked + * For shareable roots, btrfs_record_root_in_trans() is needed to + * track them, while non-subvolume roots have TRACK_DIRTY bit, they + * don't need to set this manually. + */ + BTRFS_ROOT_SHAREABLE, BTRFS_ROOT_TRACK_DIRTY, BTRFS_ROOT_IN_RADIX, BTRFS_ROOT_ORPHAN_ITEM_INSERTED, @@ -1055,7 +1076,7 @@ struct btrfs_root { struct btrfs_key defrag_progress; struct btrfs_key defrag_max; - /* the dirty list is only used by non-reference counted roots */ + /* The dirty list is only used by non-shareable roots */ struct list_head dirty_list; struct list_head root_list; |