diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 8bd556c8bca4..8226fb9d8f7b 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2867,6 +2867,54 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans) return 0; } +/* + * Parse an extent item's inline extents looking for a simple quotas owner ref. + * + * @fs_info: the btrfs_fs_info for this mount + * @leaf: a leaf in the extent tree containing the extent item + * @slot: the slot in the leaf where the extent item is found + * + * Returns the objectid of the root that originally allocated the extent item + * if the inline owner ref is expected and present, otherwise 0. + * + * If an extent item has an owner ref item, it will be the first inline ref + * item. Therefore the logic is to check whether there are any inline ref + * items, then check the type of the first one. + */ +u64 btrfs_get_extent_owner_root(struct btrfs_fs_info *fs_info, + struct extent_buffer *leaf, int slot) +{ + struct btrfs_extent_item *ei; + struct btrfs_extent_inline_ref *iref; + struct btrfs_extent_owner_ref *oref; + unsigned long ptr; + unsigned long end; + int type; + + if (!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)) + return 0; + + ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); + ptr = (unsigned long)(ei + 1); + end = (unsigned long)ei + btrfs_item_size(leaf, slot); + + /* No inline ref items of any kind, can't check type. */ + if (ptr == end) + return 0; + + iref = (struct btrfs_extent_inline_ref *)ptr; + type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY); + + /* We found an owner ref, get the root out of it. */ + if (type == BTRFS_EXTENT_OWNER_REF_KEY) { + oref = (struct btrfs_extent_owner_ref *)(&iref->offset); + return btrfs_extent_owner_ref_root_id(leaf, oref); + } + + /* We have inline refs, but not an owner ref. */ + return 0; +} + static int do_free_extent_accounting(struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, bool is_data) { |