1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright (c) 2020-2024 Oracle. All Rights Reserved.
4 * Author: Darrick J. Wong <djwong@kernel.org>
5 */
6#ifndef __XFS_EXCHMAPS_ITEM_H__
7#define __XFS_EXCHMAPS_ITEM_H__
8
9/*
10 * The file mapping exchange intent item helps us exchange multiple file
11 * mappings between two inode forks. It does this by tracking the range of
12 * file block offsets that still need to be exchanged, and relogs as progress
13 * happens.
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 bmbt updates.
18 *
19 * Should the system crash after the commit of the first transaction but
20 * before the commit of the final transaction in a series, log recovery will
21 * use the redo information recorded by the intent items to replay the
22 * rest of the mapping exchanges.
23 */
24
25/* kernel only XMI/XMD definitions */
26
27struct xfs_mount;
28struct kmem_cache;
29
30/*
31 * This is the incore file mapping exchange intent log item. It is used to log
32 * the fact that we are exchanging mappings between two files. It is used in
33 * conjunction with the incore file mapping exchange done log item described
34 * below.
35 *
36 * These log items follow the same rules as struct xfs_efi_log_item; see the
37 * comments about that structure (in xfs_extfree_item.h) for more details.
38 */
39struct xfs_xmi_log_item {
40 struct xfs_log_item xmi_item;
41 atomic_t xmi_refcount;
42 struct xfs_xmi_log_format xmi_format;
43};
44
45/*
46 * This is the incore file mapping exchange done log item. It is used to log
47 * the fact that an exchange mentioned in an earlier xmi item have been
48 * performed.
49 */
50struct xfs_xmd_log_item {
51 struct xfs_log_item xmd_item;
52 struct xfs_xmi_log_item *xmd_intent_log_item;
53 struct xfs_xmd_log_format xmd_format;
54};
55
56extern struct kmem_cache *xfs_xmi_cache;
57extern struct kmem_cache *xfs_xmd_cache;
58
59struct xfs_exchmaps_intent;
60
61void xfs_exchmaps_defer_add(struct xfs_trans *tp,
62 struct xfs_exchmaps_intent *xmi);
63
64#endif /* __XFS_EXCHMAPS_ITEM_H__ */
65

source code of linux/fs/xfs/xfs_exchmaps_item.h