xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/arc.h (revision fd75ca8de430ee0ba5ce650efee0ac0b85ed43e9)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
24  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25  */
26 
27 #ifndef	_SYS_ARC_H
28 #define	_SYS_ARC_H
29 
30 #include <sys/zfs_context.h>
31 
32 #ifdef	__cplusplus
33 extern "C" {
34 #endif
35 
36 #include <sys/zio.h>
37 #include <sys/dmu.h>
38 #include <sys/spa.h>
39 
40 typedef struct arc_buf_hdr arc_buf_hdr_t;
41 typedef struct arc_buf arc_buf_t;
42 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
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 	kmutex_t		b_evict_lock;
53 	void			*b_data;
54 	arc_evict_func_t	*b_efunc;
55 	void			*b_private;
56 };
57 
58 typedef enum arc_buf_contents {
59 	ARC_BUFC_DATA,				/* buffer contains data */
60 	ARC_BUFC_METADATA,			/* buffer contains metadata */
61 	ARC_BUFC_NUMTYPES
62 } arc_buf_contents_t;
63 /*
64  * These are the flags we pass into calls to the arc
65  */
66 #define	ARC_WAIT	(1 << 1)	/* perform I/O synchronously */
67 #define	ARC_NOWAIT	(1 << 2)	/* perform I/O asynchronously */
68 #define	ARC_PREFETCH	(1 << 3)	/* I/O is a prefetch */
69 #define	ARC_CACHED	(1 << 4)	/* I/O was already in cache */
70 #define	ARC_L2CACHE	(1 << 5)	/* cache in L2ARC */
71 #define	ARC_L2COMPRESS	(1 << 6)	/* compress in L2ARC */
72 
73 /*
74  * The following breakdows of arc_size exist for kstat only.
75  */
76 typedef enum arc_space_type {
77 	ARC_SPACE_DATA,
78 	ARC_SPACE_HDRS,
79 	ARC_SPACE_L2HDRS,
80 	ARC_SPACE_OTHER,
81 	ARC_SPACE_NUMTYPES
82 } arc_space_type_t;
83 
84 void arc_space_consume(uint64_t space, arc_space_type_t type);
85 void arc_space_return(uint64_t space, arc_space_type_t type);
86 void *arc_data_buf_alloc(uint64_t space);
87 void arc_data_buf_free(void *buf, uint64_t space);
88 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
89     arc_buf_contents_t type);
90 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
91 void arc_return_buf(arc_buf_t *buf, void *tag);
92 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
93 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
94 boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
95 int arc_buf_size(arc_buf_t *buf);
96 void arc_release(arc_buf_t *buf, void *tag);
97 int arc_released(arc_buf_t *buf);
98 void arc_buf_freeze(arc_buf_t *buf);
99 void arc_buf_thaw(arc_buf_t *buf);
100 boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
101 #ifdef ZFS_DEBUG
102 int arc_referenced(arc_buf_t *buf);
103 #endif
104 
105 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
106     arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
107     uint32_t *arc_flags, const zbookmark_phys_t *zb);
108 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
109     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
110     const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone,
111     arc_done_func_t *done, void *private, zio_priority_t priority,
112     int zio_flags, const zbookmark_phys_t *zb);
113 void arc_freed(spa_t *spa, const blkptr_t *bp);
114 
115 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
116 boolean_t arc_clear_callback(arc_buf_t *buf);
117 
118 void arc_flush(spa_t *spa);
119 void arc_tempreserve_clear(uint64_t reserve);
120 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
121 
122 void arc_init(void);
123 void arc_fini(void);
124 
125 /*
126  * Level 2 ARC
127  */
128 
129 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
130 void l2arc_remove_vdev(vdev_t *vd);
131 boolean_t l2arc_vdev_present(vdev_t *vd);
132 void l2arc_init(void);
133 void l2arc_fini(void);
134 void l2arc_start(void);
135 void l2arc_stop(void);
136 
137 #ifndef _KERNEL
138 extern boolean_t arc_watch;
139 extern int arc_procfd;
140 #endif
141 
142 #ifdef	__cplusplus
143 }
144 #endif
145 
146 #endif /* _SYS_ARC_H */
147