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_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
27 struct xfs_mount;
28 struct 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 */
50 struct 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
58 static inline size_t
59 xfs_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 */
71 struct 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
77 extern struct kmem_zone *xfs_cui_zone;
78 extern struct kmem_zone *xfs_cud_zone;
79
80 struct xfs_cui_log_item *xfs_cui_init(struct xfs_mount *, uint);
81 void xfs_cui_item_free(struct xfs_cui_log_item *);
82 void xfs_cui_release(struct xfs_cui_log_item *);
83 int xfs_cui_recover(struct xfs_trans *parent_tp, struct xfs_cui_log_item *cuip);
84
85 #endif /* __XFS_REFCOUNT_ITEM_H__ */