xref: /OK3568_Linux_fs/kernel/fs/xfs/xfs_refcount_item.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0+
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright (C) 2016 Oracle.  All Rights Reserved.
4*4882a593Smuzhiyun  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun #ifndef	__XFS_REFCOUNT_ITEM_H__
7*4882a593Smuzhiyun #define	__XFS_REFCOUNT_ITEM_H__
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun /*
10*4882a593Smuzhiyun  * There are (currently) two pairs of refcount btree redo item types:
11*4882a593Smuzhiyun  * increase and decrease.  The log items for these are CUI (refcount
12*4882a593Smuzhiyun  * update intent) and CUD (refcount update done).  The redo item type
13*4882a593Smuzhiyun  * is encoded in the flags field of each xfs_map_extent.
14*4882a593Smuzhiyun  *
15*4882a593Smuzhiyun  * *I items should be recorded in the *first* of a series of rolled
16*4882a593Smuzhiyun  * transactions, and the *D items should be recorded in the same
17*4882a593Smuzhiyun  * transaction that records the associated refcountbt updates.
18*4882a593Smuzhiyun  *
19*4882a593Smuzhiyun  * Should the system crash after the commit of the first transaction
20*4882a593Smuzhiyun  * but before the commit of the final transaction in a series, log
21*4882a593Smuzhiyun  * recovery will use the redo information recorded by the intent items
22*4882a593Smuzhiyun  * to replay the refcountbt metadata updates.
23*4882a593Smuzhiyun  */
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun /* kernel only CUI/CUD definitions */
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun struct xfs_mount;
28*4882a593Smuzhiyun struct kmem_zone;
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun /*
31*4882a593Smuzhiyun  * Max number of extents in fast allocation path.
32*4882a593Smuzhiyun  */
33*4882a593Smuzhiyun #define	XFS_CUI_MAX_FAST_EXTENTS	16
34*4882a593Smuzhiyun 
35*4882a593Smuzhiyun /*
36*4882a593Smuzhiyun  * This is the "refcount update intent" log item.  It is used to log
37*4882a593Smuzhiyun  * the fact that some reverse mappings need to change.  It is used in
38*4882a593Smuzhiyun  * conjunction with the "refcount update done" log item described
39*4882a593Smuzhiyun  * below.
40*4882a593Smuzhiyun  *
41*4882a593Smuzhiyun  * These log items follow the same rules as struct xfs_efi_log_item;
42*4882a593Smuzhiyun  * see the comments about that structure (in xfs_extfree_item.h) for
43*4882a593Smuzhiyun  * more details.
44*4882a593Smuzhiyun  */
45*4882a593Smuzhiyun struct xfs_cui_log_item {
46*4882a593Smuzhiyun 	struct xfs_log_item		cui_item;
47*4882a593Smuzhiyun 	atomic_t			cui_refcount;
48*4882a593Smuzhiyun 	atomic_t			cui_next_extent;
49*4882a593Smuzhiyun 	struct xfs_cui_log_format	cui_format;
50*4882a593Smuzhiyun };
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun static inline size_t
xfs_cui_log_item_sizeof(unsigned int nr)53*4882a593Smuzhiyun xfs_cui_log_item_sizeof(
54*4882a593Smuzhiyun 	unsigned int		nr)
55*4882a593Smuzhiyun {
56*4882a593Smuzhiyun 	return offsetof(struct xfs_cui_log_item, cui_format) +
57*4882a593Smuzhiyun 			xfs_cui_log_format_sizeof(nr);
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun /*
61*4882a593Smuzhiyun  * This is the "refcount update done" log item.  It is used to log the
62*4882a593Smuzhiyun  * fact that some refcountbt updates mentioned in an earlier cui item
63*4882a593Smuzhiyun  * have been performed.
64*4882a593Smuzhiyun  */
65*4882a593Smuzhiyun struct xfs_cud_log_item {
66*4882a593Smuzhiyun 	struct xfs_log_item		cud_item;
67*4882a593Smuzhiyun 	struct xfs_cui_log_item		*cud_cuip;
68*4882a593Smuzhiyun 	struct xfs_cud_log_format	cud_format;
69*4882a593Smuzhiyun };
70*4882a593Smuzhiyun 
71*4882a593Smuzhiyun extern struct kmem_zone	*xfs_cui_zone;
72*4882a593Smuzhiyun extern struct kmem_zone	*xfs_cud_zone;
73*4882a593Smuzhiyun 
74*4882a593Smuzhiyun #endif	/* __XFS_REFCOUNT_ITEM_H__ */
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