xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/arc.h (revision a33595abb743c413156e63834db73f4df0fdc485)
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 typedef enum arc_flags
50 {
51 	/*
52 	 * Public flags that can be passed into the ARC by external consumers.
53 	 */
54 	ARC_FLAG_NONE			= 1 << 0,	/* No flags set */
55 	ARC_FLAG_WAIT			= 1 << 1,	/* perform sync I/O */
56 	ARC_FLAG_NOWAIT			= 1 << 2,	/* perform async I/O */
57 	ARC_FLAG_PREFETCH		= 1 << 3,	/* I/O is a prefetch */
58 	ARC_FLAG_CACHED			= 1 << 4,	/* I/O was in cache */
59 	ARC_FLAG_L2CACHE		= 1 << 5,	/* cache in L2ARC */
60 	ARC_FLAG_L2COMPRESS		= 1 << 6,	/* compress in L2ARC */
61 
62 	/*
63 	 * Private ARC flags.  These flags are private ARC only flags that
64 	 * will show up in b_flags in the arc_hdr_buf_t. These flags should
65 	 * only be set by ARC code.
66 	 */
67 	ARC_FLAG_IN_HASH_TABLE		= 1 << 7,	/* buffer is hashed */
68 	ARC_FLAG_IO_IN_PROGRESS		= 1 << 8,	/* I/O in progress */
69 	ARC_FLAG_IO_ERROR		= 1 << 9,	/* I/O failed for buf */
70 	ARC_FLAG_FREED_IN_READ		= 1 << 10,	/* freed during read */
71 	ARC_FLAG_BUF_AVAILABLE		= 1 << 11,	/* block not in use */
72 	ARC_FLAG_INDIRECT		= 1 << 12,	/* indirect block */
73 	ARC_FLAG_FREE_IN_PROGRESS	= 1 << 13,	/*  about to be freed */
74 	ARC_FLAG_L2_WRITING		= 1 << 14,	/* write in progress */
75 	ARC_FLAG_L2_EVICTED		= 1 << 15,	/* evicted during I/O */
76 	ARC_FLAG_L2_WRITE_HEAD		= 1 << 16,	/* head of write list */
77 } arc_flags_t;
78 
79 struct arc_buf {
80 	arc_buf_hdr_t		*b_hdr;
81 	arc_buf_t		*b_next;
82 	kmutex_t		b_evict_lock;
83 	void			*b_data;
84 	arc_evict_func_t	*b_efunc;
85 	void			*b_private;
86 };
87 
88 typedef enum arc_buf_contents {
89 	ARC_BUFC_DATA,				/* buffer contains data */
90 	ARC_BUFC_METADATA,			/* buffer contains metadata */
91 	ARC_BUFC_NUMTYPES
92 } arc_buf_contents_t;
93 
94 /*
95  * The following breakdows of arc_size exist for kstat only.
96  */
97 typedef enum arc_space_type {
98 	ARC_SPACE_DATA,
99 	ARC_SPACE_HDRS,
100 	ARC_SPACE_L2HDRS,
101 	ARC_SPACE_OTHER,
102 	ARC_SPACE_NUMTYPES
103 } arc_space_type_t;
104 
105 void arc_space_consume(uint64_t space, arc_space_type_t type);
106 void arc_space_return(uint64_t space, arc_space_type_t type);
107 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
108     arc_buf_contents_t type);
109 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
110 void arc_return_buf(arc_buf_t *buf, void *tag);
111 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
112 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
113 boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
114 int arc_buf_size(arc_buf_t *buf);
115 void arc_release(arc_buf_t *buf, void *tag);
116 int arc_released(arc_buf_t *buf);
117 void arc_buf_freeze(arc_buf_t *buf);
118 void arc_buf_thaw(arc_buf_t *buf);
119 boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
120 #ifdef ZFS_DEBUG
121 int arc_referenced(arc_buf_t *buf);
122 #endif
123 
124 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
125     arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
126     arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
127 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
128     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
129     const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone,
130     arc_done_func_t *done, void *private, zio_priority_t priority,
131     int zio_flags, const zbookmark_phys_t *zb);
132 void arc_freed(spa_t *spa, const blkptr_t *bp);
133 
134 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
135 boolean_t arc_clear_callback(arc_buf_t *buf);
136 
137 void arc_flush(spa_t *spa);
138 void arc_tempreserve_clear(uint64_t reserve);
139 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
140 
141 void arc_init(void);
142 void arc_fini(void);
143 
144 /*
145  * Level 2 ARC
146  */
147 
148 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
149 void l2arc_remove_vdev(vdev_t *vd);
150 boolean_t l2arc_vdev_present(vdev_t *vd);
151 void l2arc_init(void);
152 void l2arc_fini(void);
153 void l2arc_start(void);
154 void l2arc_stop(void);
155 
156 #ifndef _KERNEL
157 extern boolean_t arc_watch;
158 extern int arc_procfd;
159 #endif
160 
161 #ifdef	__cplusplus
162 }
163 #endif
164 
165 #endif /* _SYS_ARC_H */
166