xref: /titanic_41/usr/src/uts/common/fs/zfs/sys/arc.h (revision 16dd44c265271a75647fb0bb41109bb7c585a526)
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 2009 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
32 extern "C" {
33 #endif
34 
35 #include <sys/zio.h>
36 #include <sys/dmu.h>
37 #include <sys/spa.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 int arc_evict_func_t(void *private);
43 
44 /* generic arc_done_func_t's which you can use */
45 arc_done_func_t arc_bcopy_func;
46 arc_done_func_t arc_getbuf_func;
47 
48 struct 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 
57 typedef 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  */
74 typedef 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 
82 void arc_space_consume(uint64_t space, arc_space_type_t type);
83 void arc_space_return(uint64_t space, arc_space_type_t type);
84 void *arc_data_buf_alloc(uint64_t space);
85 void arc_data_buf_free(void *buf, uint64_t space);
86 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
87     arc_buf_contents_t type);
88 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
89 int arc_buf_remove_ref(arc_buf_t *buf, void *tag);
90 int arc_buf_size(arc_buf_t *buf);
91 void arc_release(arc_buf_t *buf, void *tag);
92 int arc_released(arc_buf_t *buf);
93 int arc_has_callback(arc_buf_t *buf);
94 void arc_buf_freeze(arc_buf_t *buf);
95 void arc_buf_thaw(arc_buf_t *buf);
96 #ifdef ZFS_DEBUG
97 int arc_referenced(arc_buf_t *buf);
98 #endif
99 
100 typedef struct writeprops {
101 	dmu_object_type_t wp_type;
102 	uint8_t wp_level;
103 	uint8_t wp_copies;
104 	uint8_t wp_dncompress, wp_oscompress;
105 	uint8_t wp_dnchecksum, wp_oschecksum;
106 } writeprops_t;
107 
108 void write_policy(spa_t *spa, const writeprops_t *wp, zio_prop_t *zp);
109 int arc_read(zio_t *pio, spa_t *spa, blkptr_t *bp, arc_buf_t *pbuf,
110     arc_done_func_t *done, void *private, int priority, int zio_flags,
111     uint32_t *arc_flags, const zbookmark_t *zb);
112 int arc_read_nolock(zio_t *pio, spa_t *spa, blkptr_t *bp,
113     arc_done_func_t *done, void *private, int priority, int flags,
114     uint32_t *arc_flags, const zbookmark_t *zb);
115 zio_t *arc_write(zio_t *pio, spa_t *spa, const writeprops_t *wp,
116     boolean_t l2arc, uint64_t txg, blkptr_t *bp, arc_buf_t *buf,
117     arc_done_func_t *ready, arc_done_func_t *done, void *private, int priority,
118     int zio_flags, const zbookmark_t *zb);
119 int arc_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
120     zio_done_func_t *done, void *private, uint32_t arc_flags);
121 int arc_tryread(spa_t *spa, blkptr_t *bp, void *data);
122 
123 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
124 int arc_buf_evict(arc_buf_t *buf);
125 
126 void arc_flush(spa_t *spa);
127 void arc_tempreserve_clear(uint64_t reserve);
128 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
129 
130 void arc_init(void);
131 void arc_fini(void);
132 
133 /*
134  * Level 2 ARC
135  */
136 
137 void l2arc_add_vdev(spa_t *spa, vdev_t *vd, uint64_t start, uint64_t end);
138 void l2arc_remove_vdev(vdev_t *vd);
139 boolean_t l2arc_vdev_present(vdev_t *vd);
140 void l2arc_init(void);
141 void l2arc_fini(void);
142 void l2arc_start(void);
143 void l2arc_stop(void);
144 
145 #ifdef	__cplusplus
146 }
147 #endif
148 
149 #endif /* _SYS_ARC_H */
150