1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2015 by Delphix. All rights reserved.
*/
#ifndef _SYS_REFCOUNT_H
#define _SYS_REFCOUNT_H
#include <sys/inttypes.h>
#include <sys/list.h>
#include <sys/zfs_context.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* If the reference is held only by the calling function and not any
* particular object, use FTAG (which is a string) for the holder_tag.
* Otherwise, use the object that holds the reference.
*/
#define FTAG ((char *)(uintptr_t)__func__)
/*
* Starting with 4.11, torvalds/linux@f405df5, the linux kernel defines a
* refcount_t type of its own. The macro below effectively changes references
* in the ZFS code from refcount_t to zfs_refcount_t at compile time, so that
* existing code need not be altered, reducing conflicts when landing openZFS
* patches.
*/
#define refcount_t zfs_refcount_t
#define refcount_add zfs_refcount_add
#ifdef ZFS_DEBUG
typedef struct reference {
list_node_t ref_link;
void *ref_holder;
uint64_t ref_number;
uint8_t *ref_removed;
} reference_t;
typedef struct refcount {
kmutex_t rc_mtx;
boolean_t rc_tracked;
list_t rc_list;
list_t rc_removed;
uint64_t rc_count;
uint64_t rc_removed_count;
} zfs_refcount_t;
/* Note: refcount_t must be initialized with refcount_create[_untracked]() */
void refcount_create(refcount_t *rc);
void refcount_create_untracked(refcount_t *rc);
void refcount_create_tracked(refcount_t *rc);
void refcount_destroy(refcount_t *rc);
void refcount_destroy_many(refcount_t *rc, uint64_t number);
int refcount_is_zero(refcount_t *rc);
int64_t refcount_count(refcount_t *rc);
int64_t zfs_refcount_add(refcount_t *rc, void *holder_tag);
int64_t refcount_remove(refcount_t *rc, void *holder_tag);
int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag);
int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag);
void refcount_transfer(refcount_t *dst, refcount_t *src);
void refcount_transfer_ownership(refcount_t *, void *, void *);
boolean_t refcount_held(refcount_t *, void *);
boolean_t refcount_not_held(refcount_t *, void *);
void refcount_init(void);
void refcount_fini(void);
#else /* ZFS_DEBUG */
typedef struct refcount {
uint64_t rc_count;
} refcount_t;
#define refcount_create(rc) ((rc)->rc_count = 0)
#define refcount_create_untracked(rc) ((rc)->rc_count = 0)
#define refcount_create_tracked(rc) ((rc)->rc_count = 0)
#define refcount_destroy(rc) ((rc)->rc_count = 0)
#define refcount_destroy_many(rc, number) ((rc)->rc_count = 0)
#define refcount_is_zero(rc) ((rc)->rc_count == 0)
#define refcount_count(rc) ((rc)->rc_count)
#define zfs_refcount_add(rc, holder) atomic_inc_64_nv(&(rc)->rc_count)
#define refcount_remove(rc, holder) atomic_dec_64_nv(&(rc)->rc_count)
#define refcount_add_many(rc, number, holder) \
atomic_add_64_nv(&(rc)->rc_count, number)
#define refcount_remove_many(rc, number, holder) \
atomic_add_64_nv(&(rc)->rc_count, -number)
#define refcount_transfer(dst, src) { \
uint64_t __tmp = (src)->rc_count; \
atomic_add_64(&(src)->rc_count, -__tmp); \
atomic_add_64(&(dst)->rc_count, __tmp); \
}
#define refcount_transfer_ownership(rc, current_holder, new_holder) (void)0
#define refcount_held(rc, holder) ((rc)->rc_count > 0)
#define refcount_not_held(rc, holder) (B_TRUE)
#define refcount_init()
#define refcount_fini()
#endif /* ZFS_DEBUG */
#ifdef __cplusplus
}
#endif
#endif /* _SYS_REFCOUNT_H */
|
