1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Copyright (C) 2016 Oracle. All Rights Reserved. |
4 | * Author: Darrick J. Wong <darrick.wong@oracle.com> |
5 | */ |
6 | #ifndef __XFS_REFCOUNT_ITEM_H__ |
7 | #define __XFS_REFCOUNT_ITEM_H__ |
8 | |
9 | /* |
10 | * There are (currently) two pairs of refcount btree redo item types: |
11 | * increase and decrease. The log items for these are CUI (refcount |
12 | * update intent) and CUD (refcount update done). The redo item type |
13 | * is encoded in the flags field of each xfs_map_extent. |
14 | * |
15 | * *I items should be recorded in the *first* of a series of rolled |
16 | * transactions, and the *D items should be recorded in the same |
17 | * transaction that records the associated refcountbt updates. |
18 | * |
19 | * Should the system crash after the commit of the first transaction |
20 | * but before the commit of the final transaction in a series, log |
21 | * recovery will use the redo information recorded by the intent items |
22 | * to replay the refcountbt metadata updates. |
23 | */ |
24 | |
25 | /* kernel only CUI/CUD definitions */ |
26 | |
27 | struct xfs_mount; |
28 | struct kmem_cache; |
29 | |
30 | /* |
31 | * Max number of extents in fast allocation path. |
32 | */ |
33 | #define XFS_CUI_MAX_FAST_EXTENTS 16 |
34 | |
35 | /* |
36 | * This is the "refcount update intent" log item. It is used to log |
37 | * the fact that some reverse mappings need to change. It is used in |
38 | * conjunction with the "refcount update done" log item described |
39 | * below. |
40 | * |
41 | * These log items follow the same rules as struct xfs_efi_log_item; |
42 | * see the comments about that structure (in xfs_extfree_item.h) for |
43 | * more details. |
44 | */ |
45 | struct xfs_cui_log_item { |
46 | struct xfs_log_item cui_item; |
47 | atomic_t cui_refcount; |
48 | atomic_t cui_next_extent; |
49 | struct xfs_cui_log_format cui_format; |
50 | }; |
51 | |
52 | static inline size_t |
53 | xfs_cui_log_item_sizeof( |
54 | unsigned int nr) |
55 | { |
56 | return offsetof(struct xfs_cui_log_item, cui_format) + |
57 | xfs_cui_log_format_sizeof(nr); |
58 | } |
59 | |
60 | /* |
61 | * This is the "refcount update done" log item. It is used to log the |
62 | * fact that some refcountbt updates mentioned in an earlier cui item |
63 | * have been performed. |
64 | */ |
65 | struct xfs_cud_log_item { |
66 | struct xfs_log_item cud_item; |
67 | struct xfs_cui_log_item *cud_cuip; |
68 | struct xfs_cud_log_format cud_format; |
69 | }; |
70 | |
71 | extern struct kmem_cache *xfs_cui_cache; |
72 | extern struct kmem_cache *xfs_cud_cache; |
73 | |
74 | #endif /* __XFS_REFCOUNT_ITEM_H__ */ |
75 | |