mm/memunmap: don't access uninitialized memmap in memunmap_pages()
[linux-2.6-block.git] / fs / xfs / xfs_refcount_item.h
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0b61f8a4 1// SPDX-License-Identifier: GPL-2.0+
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2/*
3 * Copyright (C) 2016 Oracle. All Rights Reserved.
baf4bcac 4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
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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
27struct xfs_mount;
28struct kmem_zone;
29
30/*
31 * Max number of extents in fast allocation path.
32 */
33#define XFS_CUI_MAX_FAST_EXTENTS 16
34
35/*
36 * Define CUI flag bits. Manipulated by set/clear/test_bit operators.
37 */
38#define XFS_CUI_RECOVERED 1
39
40/*
41 * This is the "refcount update intent" log item. It is used to log
42 * the fact that some reverse mappings need to change. It is used in
43 * conjunction with the "refcount update done" log item described
44 * below.
45 *
46 * These log items follow the same rules as struct xfs_efi_log_item;
47 * see the comments about that structure (in xfs_extfree_item.h) for
48 * more details.
49 */
50struct xfs_cui_log_item {
51 struct xfs_log_item cui_item;
52 atomic_t cui_refcount;
53 atomic_t cui_next_extent;
54 unsigned long cui_flags; /* misc flags */
55 struct xfs_cui_log_format cui_format;
56};
57
58static inline size_t
59xfs_cui_log_item_sizeof(
60 unsigned int nr)
61{
62 return offsetof(struct xfs_cui_log_item, cui_format) +
63 xfs_cui_log_format_sizeof(nr);
64}
65
66/*
67 * This is the "refcount update done" log item. It is used to log the
68 * fact that some refcountbt updates mentioned in an earlier cui item
69 * have been performed.
70 */
71struct xfs_cud_log_item {
72 struct xfs_log_item cud_item;
73 struct xfs_cui_log_item *cud_cuip;
74 struct xfs_cud_log_format cud_format;
75};
76
77extern struct kmem_zone *xfs_cui_zone;
78extern struct kmem_zone *xfs_cud_zone;
79
80struct xfs_cui_log_item *xfs_cui_init(struct xfs_mount *, uint);
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81void xfs_cui_item_free(struct xfs_cui_log_item *);
82void xfs_cui_release(struct xfs_cui_log_item *);
fbfa977d 83int xfs_cui_recover(struct xfs_trans *parent_tp, struct xfs_cui_log_item *cuip);
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84
85#endif /* __XFS_REFCOUNT_ITEM_H__ */