xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/arc.h (revision c717a56157ae0e6fca6a1e3689ae1edc385716a3)
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 2007 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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/zfs_context.h>
32 
33 #ifdef	__cplusplus
34 extern "C" {
35 #endif
36 
37 #include <sys/zio.h>
38 
39 typedef struct arc_buf_hdr arc_buf_hdr_t;
40 typedef struct arc_buf arc_buf_t;
41 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
42 typedef void arc_byteswap_func_t(void *buf, size_t size);
43 typedef int arc_evict_func_t(void *private);
44 
45 /* generic arc_done_func_t's which you can use */
46 arc_done_func_t arc_bcopy_func;
47 arc_done_func_t arc_getbuf_func;
48 
49 struct arc_buf {
50 	arc_buf_hdr_t		*b_hdr;
51 	arc_buf_t		*b_next;
52 	void			*b_data;
53 	arc_evict_func_t	*b_efunc;
54 	void			*b_private;
55 };
56 
57 typedef enum arc_buf_contents {
58 	ARC_BUFC_UNDEF,				/* buffer contents undefined */
59 	ARC_BUFC_DATA,				/* buffer contains data */
60 	ARC_BUFC_METADATA			/* buffer contains metadata */
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 
70 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
71     arc_buf_contents_t type);
72 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
73 int arc_buf_remove_ref(arc_buf_t *buf, void *tag);
74 int arc_buf_size(arc_buf_t *buf);
75 void arc_release(arc_buf_t *buf, void *tag);
76 int arc_released(arc_buf_t *buf);
77 int arc_has_callback(arc_buf_t *buf);
78 void arc_buf_freeze(arc_buf_t *buf);
79 void arc_buf_thaw(arc_buf_t *buf);
80 #ifdef ZFS_DEBUG
81 int arc_referenced(arc_buf_t *buf);
82 #endif
83 
84 int arc_read(zio_t *pio, spa_t *spa, blkptr_t *bp, arc_byteswap_func_t *swap,
85     arc_done_func_t *done, void *private, int priority, int flags,
86     uint32_t *arc_flags, zbookmark_t *zb);
87 zio_t *arc_write(zio_t *pio, spa_t *spa, int checksum, int compress,
88     int ncopies, uint64_t txg, blkptr_t *bp, arc_buf_t *buf,
89     arc_done_func_t *ready, arc_done_func_t *done, void *private, int priority,
90     int flags, zbookmark_t *zb);
91 int arc_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
92     zio_done_func_t *done, void *private, uint32_t arc_flags);
93 int arc_tryread(spa_t *spa, blkptr_t *bp, void *data);
94 
95 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
96 int arc_buf_evict(arc_buf_t *buf);
97 
98 void arc_flush(void);
99 void arc_tempreserve_clear(uint64_t tempreserve);
100 int arc_tempreserve_space(uint64_t tempreserve);
101 
102 void arc_init(void);
103 void arc_fini(void);
104 
105 #ifdef	__cplusplus
106 }
107 #endif
108 
109 #endif /* _SYS_ARC_H */
110