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_RMAP_ITEM_H__ |
7 | #define __XFS_RMAP_ITEM_H__ |
8 | |
9 | /* |
10 | * There are (currently) three pairs of rmap btree redo item types: map, unmap, |
11 | * and convert. The common abbreviations for these are RUI (rmap update |
12 | * intent) and RUD (rmap update done). The redo item type is encoded in the |
13 | * 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 transaction |
17 | * that records the associated rmapbt updates. Typically, the first |
18 | * transaction will record a bmbt update, followed by some number of |
19 | * transactions containing rmapbt updates, and finally transactions with any |
20 | * bnobt/cntbt updates. |
21 | * |
22 | * Should the system crash after the commit of the first transaction but |
23 | * before the commit of the final transaction in a series, log recovery will |
24 | * use the redo information recorded by the intent items to replay the |
25 | * (rmapbt/bnobt/cntbt) metadata updates in the non-first transaction. |
26 | */ |
27 | |
28 | /* kernel only RUI/RUD definitions */ |
29 | |
30 | struct xfs_mount; |
31 | struct kmem_cache; |
32 | |
33 | /* |
34 | * Max number of extents in fast allocation path. |
35 | */ |
36 | #define XFS_RUI_MAX_FAST_EXTENTS 16 |
37 | |
38 | /* |
39 | * This is the "rmap update intent" log item. It is used to log the fact that |
40 | * some reverse mappings need to change. It is used in conjunction with the |
41 | * "rmap update done" log item described below. |
42 | * |
43 | * These log items follow the same rules as struct xfs_efi_log_item; see the |
44 | * comments about that structure (in xfs_extfree_item.h) for more details. |
45 | */ |
46 | struct xfs_rui_log_item { |
47 | struct xfs_log_item rui_item; |
48 | atomic_t rui_refcount; |
49 | atomic_t rui_next_extent; |
50 | struct xfs_rui_log_format rui_format; |
51 | }; |
52 | |
53 | static inline size_t |
54 | xfs_rui_log_item_sizeof( |
55 | unsigned int nr) |
56 | { |
57 | return offsetof(struct xfs_rui_log_item, rui_format) + |
58 | xfs_rui_log_format_sizeof(nr); |
59 | } |
60 | |
61 | /* |
62 | * This is the "rmap update done" log item. It is used to log the fact that |
63 | * some rmapbt updates mentioned in an earlier rui item have been performed. |
64 | */ |
65 | struct xfs_rud_log_item { |
66 | struct xfs_log_item rud_item; |
67 | struct xfs_rui_log_item *rud_ruip; |
68 | struct xfs_rud_log_format rud_format; |
69 | }; |
70 | |
71 | extern struct kmem_cache *xfs_rui_cache; |
72 | extern struct kmem_cache *xfs_rud_cache; |
73 | |
74 | #endif /* __XFS_RMAP_ITEM_H__ */ |
75 | |