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_zone;
32
33 /*
34 * Max number of extents in fast allocation path.
35 */
36 #define XFS_RUI_MAX_FAST_EXTENTS 16
37
38 /*
39 * Define RUI flag bits. Manipulated by set/clear/test_bit operators.
40 */
41 #define XFS_RUI_RECOVERED 1
42
43 /*
44 * This is the "rmap update intent" log item. It is used to log the fact that
45 * some reverse mappings need to change. It is used in conjunction with the
46 * "rmap update done" log item described below.
47 *
48 * These log items follow the same rules as struct xfs_efi_log_item; see the
49 * comments about that structure (in xfs_extfree_item.h) for more details.
50 */
51 struct xfs_rui_log_item {
52 struct xfs_log_item rui_item;
53 atomic_t rui_refcount;
54 atomic_t rui_next_extent;
55 unsigned long rui_flags; /* misc flags */
56 struct xfs_rui_log_format rui_format;
57 };
58
59 static inline size_t
60 xfs_rui_log_item_sizeof(
61 unsigned int nr)
62 {
63 return offsetof(struct xfs_rui_log_item, rui_format) +
64 xfs_rui_log_format_sizeof(nr);
65 }
66
67 /*
68 * This is the "rmap update done" log item. It is used to log the fact that
69 * some rmapbt updates mentioned in an earlier rui item have been performed.
70 */
71 struct xfs_rud_log_item {
72 struct xfs_log_item rud_item;
73 struct xfs_rui_log_item *rud_ruip;
74 struct xfs_rud_log_format rud_format;
75 };
76
77 extern struct kmem_zone *xfs_rui_zone;
78 extern struct kmem_zone *xfs_rud_zone;
79
80 struct xfs_rui_log_item *xfs_rui_init(struct xfs_mount *, uint);
81 int xfs_rui_copy_format(struct xfs_log_iovec *buf,
82 struct xfs_rui_log_format *dst_rui_fmt);
83 void xfs_rui_item_free(struct xfs_rui_log_item *);
84 void xfs_rui_release(struct xfs_rui_log_item *);
85 int xfs_rui_recover(struct xfs_mount *mp, struct xfs_rui_log_item *ruip);
86
87 #endif /* __XFS_RMAP_ITEM_H__ */