arc.h revision 1.1.1.2 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#ifndef	_SYS_ARC_H
27#define	_SYS_ARC_H
28
29#include <sys/zfs_context.h>
30
31#ifdef	__cplusplus
32extern "C" {
33#endif
34
35#include <sys/zio.h>
36#include <sys/dmu.h>
37#include <sys/spa.h>
38
39typedef struct arc_buf_hdr arc_buf_hdr_t;
40typedef struct arc_buf arc_buf_t;
41typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
42typedef int arc_evict_func_t(void *private);
43
44/* generic arc_done_func_t's which you can use */
45arc_done_func_t arc_bcopy_func;
46arc_done_func_t arc_getbuf_func;
47
48struct arc_buf {
49	arc_buf_hdr_t		*b_hdr;
50	arc_buf_t		*b_next;
51	krwlock_t		b_lock;
52	void			*b_data;
53	arc_evict_func_t	*b_efunc;
54	void			*b_private;
55};
56
57typedef enum arc_buf_contents {
58	ARC_BUFC_DATA,				/* buffer contains data */
59	ARC_BUFC_METADATA,			/* buffer contains metadata */
60	ARC_BUFC_NUMTYPES
61} arc_buf_contents_t;
62/*
63 * These are the flags we pass into calls to the arc
64 */
65#define	ARC_WAIT	(1 << 1)	/* perform I/O synchronously */
66#define	ARC_NOWAIT	(1 << 2)	/* perform I/O asynchronously */
67#define	ARC_PREFETCH	(1 << 3)	/* I/O is a prefetch */
68#define	ARC_CACHED	(1 << 4)	/* I/O was already in cache */
69#define	ARC_L2CACHE	(1 << 5)	/* cache in L2ARC */
70
71/*
72 * The following breakdows of arc_size exist for kstat only.
73 */
74typedef enum arc_space_type {
75	ARC_SPACE_DATA,
76	ARC_SPACE_HDRS,
77	ARC_SPACE_L2HDRS,
78	ARC_SPACE_OTHER,
79	ARC_SPACE_NUMTYPES
80} arc_space_type_t;
81
82void arc_space_consume(uint64_t space, arc_space_type_t type);
83void arc_space_return(uint64_t space, arc_space_type_t type);
84void *arc_data_buf_alloc(uint64_t space);
85void arc_data_buf_free(void *buf, uint64_t space);
86arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
87    arc_buf_contents_t type);
88arc_buf_t *arc_loan_buf(spa_t *spa, int size);
89void arc_return_buf(arc_buf_t *buf, void *tag);
90void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
91void arc_buf_add_ref(arc_buf_t *buf, void *tag);
92int arc_buf_remove_ref(arc_buf_t *buf, void *tag);
93int arc_buf_size(arc_buf_t *buf);
94void arc_release(arc_buf_t *buf, void *tag);
95int arc_released(arc_buf_t *buf);
96int arc_has_callback(arc_buf_t *buf);
97void arc_buf_freeze(arc_buf_t *buf);
98void arc_buf_thaw(arc_buf_t *buf);
99#ifdef ZFS_DEBUG
100int arc_referenced(arc_buf_t *buf);
101#endif
102
103int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, arc_buf_t *pbuf,
104    arc_done_func_t *done, void *private, int priority, int zio_flags,
105    uint32_t *arc_flags, const zbookmark_t *zb);
106int arc_read_nolock(zio_t *pio, spa_t *spa, const blkptr_t *bp,
107    arc_done_func_t *done, void *private, int priority, int flags,
108    uint32_t *arc_flags, const zbookmark_t *zb);
109zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
110    blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
111    arc_done_func_t *ready, arc_done_func_t *done, void *private,
112    int priority, int zio_flags, const zbookmark_t *zb);
113void arc_free(spa_t *spa, const blkptr_t *bp);
114
115void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
116int arc_buf_evict(arc_buf_t *buf);
117
118void arc_flush(spa_t *spa);
119void arc_tempreserve_clear(uint64_t reserve);
120int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
121
122void arc_init(void);
123void arc_fini(void);
124
125/*
126 * Level 2 ARC
127 */
128
129void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
130void l2arc_remove_vdev(vdev_t *vd);
131boolean_t l2arc_vdev_present(vdev_t *vd);
132void l2arc_init(void);
133void l2arc_fini(void);
134void l2arc_start(void);
135void l2arc_stop(void);
136
137#ifdef	__cplusplus
138}
139#endif
140
141#endif /* _SYS_ARC_H */
142