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Linux kernel mirror (for testing)
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1/*
2 * Copyright (C) 2016 Oracle. All Rights Reserved.
3 *
4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it would be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
19 */
20#ifndef __XFS_BMAP_ITEM_H__
21#define __XFS_BMAP_ITEM_H__
22
23/*
24 * There are (currently) two pairs of bmap btree redo item types: map & unmap.
25 * The common abbreviations for these are BUI (bmap update intent) and BUD
26 * (bmap update done). The redo item type is encoded in the flags field of
27 * each xfs_map_extent.
28 *
29 * *I items should be recorded in the *first* of a series of rolled
30 * transactions, and the *D items should be recorded in the same transaction
31 * that records the associated bmbt updates.
32 *
33 * Should the system crash after the commit of the first transaction but
34 * before the commit of the final transaction in a series, log recovery will
35 * use the redo information recorded by the intent items to replay the
36 * bmbt metadata updates in the non-first transaction.
37 */
38
39/* kernel only BUI/BUD definitions */
40
41struct xfs_mount;
42struct kmem_zone;
43
44/*
45 * Max number of extents in fast allocation path.
46 */
47#define XFS_BUI_MAX_FAST_EXTENTS 1
48
49/*
50 * Define BUI flag bits. Manipulated by set/clear/test_bit operators.
51 */
52#define XFS_BUI_RECOVERED 1
53
54/*
55 * This is the "bmap update intent" log item. It is used to log the fact that
56 * some reverse mappings need to change. It is used in conjunction with the
57 * "bmap update done" log item described below.
58 *
59 * These log items follow the same rules as struct xfs_efi_log_item; see the
60 * comments about that structure (in xfs_extfree_item.h) for more details.
61 */
62struct xfs_bui_log_item {
63 struct xfs_log_item bui_item;
64 atomic_t bui_refcount;
65 atomic_t bui_next_extent;
66 unsigned long bui_flags; /* misc flags */
67 struct xfs_bui_log_format bui_format;
68};
69
70static inline size_t
71xfs_bui_log_item_sizeof(
72 unsigned int nr)
73{
74 return offsetof(struct xfs_bui_log_item, bui_format) +
75 xfs_bui_log_format_sizeof(nr);
76}
77
78/*
79 * This is the "bmap update done" log item. It is used to log the fact that
80 * some bmbt updates mentioned in an earlier bui item have been performed.
81 */
82struct xfs_bud_log_item {
83 struct xfs_log_item bud_item;
84 struct xfs_bui_log_item *bud_buip;
85 struct xfs_bud_log_format bud_format;
86};
87
88extern struct kmem_zone *xfs_bui_zone;
89extern struct kmem_zone *xfs_bud_zone;
90
91struct xfs_bui_log_item *xfs_bui_init(struct xfs_mount *);
92struct xfs_bud_log_item *xfs_bud_init(struct xfs_mount *,
93 struct xfs_bui_log_item *);
94void xfs_bui_item_free(struct xfs_bui_log_item *);
95void xfs_bui_release(struct xfs_bui_log_item *);
96int xfs_bui_recover(struct xfs_mount *mp, struct xfs_bui_log_item *buip);
97
98#endif /* __XFS_BMAP_ITEM_H__ */