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 /*
41 * Used by arc_flush() to inform arc_evict_state() that it should evict
42 * all available buffers from the arc state being passed in.
43 */
44 #define ARC_EVICT_ALL -1ULL
45
46 typedef struct arc_buf_hdr arc_buf_hdr_t;
47 typedef struct arc_buf arc_buf_t;
48 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
49 typedef int arc_evict_func_t(void *private);
50
51 /* generic arc_done_func_t's which you can use */
52 arc_done_func_t arc_bcopy_func;
53 arc_done_func_t arc_getbuf_func;
54
55 typedef enum arc_flags
56 {
57 /*
58 * Public flags that can be passed into the ARC by external consumers.
59 */
60 ARC_FLAG_NONE = 1 << 0, /* No flags set */
61 ARC_FLAG_WAIT = 1 << 1, /* perform sync I/O */
62 ARC_FLAG_NOWAIT = 1 << 2, /* perform async I/O */
63 ARC_FLAG_PREFETCH = 1 << 3, /* I/O is a prefetch */
64 ARC_FLAG_CACHED = 1 << 4, /* I/O was in cache */
65 ARC_FLAG_L2CACHE = 1 << 5, /* cache in L2ARC */
66 ARC_FLAG_L2COMPRESS = 1 << 6, /* compress in L2ARC */
67
68 /*
69 * Private ARC flags. These flags are private ARC only flags that
70 * will show up in b_flags in the arc_hdr_buf_t. These flags should
71 * only be set by ARC code.
72 */
73 ARC_FLAG_IN_HASH_TABLE = 1 << 7, /* buffer is hashed */
74 ARC_FLAG_IO_IN_PROGRESS = 1 << 8, /* I/O in progress */
75 ARC_FLAG_IO_ERROR = 1 << 9, /* I/O failed for buf */
76 ARC_FLAG_FREED_IN_READ = 1 << 10, /* freed during read */
77 ARC_FLAG_BUF_AVAILABLE = 1 << 11, /* block not in use */
78 ARC_FLAG_INDIRECT = 1 << 12, /* indirect block */
79 ARC_FLAG_L2_WRITING = 1 << 13, /* write in progress */
80 ARC_FLAG_L2_EVICTED = 1 << 14, /* evicted during I/O */
81 ARC_FLAG_L2_WRITE_HEAD = 1 << 15, /* head of write list */
82 /* indicates that the buffer contains metadata (otherwise, data) */
83 ARC_FLAG_BUFC_METADATA = 1 << 16,
84
85 /* Flags specifying whether optional hdr struct fields are defined */
86 ARC_FLAG_HAS_L1HDR = 1 << 17,
87 ARC_FLAG_HAS_L2HDR = 1 << 18,
88
89 /*
90 * The arc buffer's compression mode is stored in the top 7 bits of the
91 * flags field, so these dummy flags are included so that MDB can
92 * interpret the enum properly.
93 */
94 ARC_FLAG_COMPRESS_0 = 1 << 24,
95 ARC_FLAG_COMPRESS_1 = 1 << 25,
96 ARC_FLAG_COMPRESS_2 = 1 << 26,
97 ARC_FLAG_COMPRESS_3 = 1 << 27,
98 ARC_FLAG_COMPRESS_4 = 1 << 28,
99 ARC_FLAG_COMPRESS_5 = 1 << 29,
100 ARC_FLAG_COMPRESS_6 = 1 << 30
101
102 } arc_flags_t;
103
104 struct arc_buf {
105 arc_buf_hdr_t *b_hdr;
106 arc_buf_t *b_next;
107 kmutex_t b_evict_lock;
108 void *b_data;
109 arc_evict_func_t *b_efunc;
110 void *b_private;
111 };
112
113 typedef enum arc_buf_contents {
114 ARC_BUFC_DATA, /* buffer contains data */
115 ARC_BUFC_METADATA, /* buffer contains metadata */
116 ARC_BUFC_NUMTYPES
117 } arc_buf_contents_t;
118
119 /*
120 * The following breakdows of arc_size exist for kstat only.
121 */
122 typedef enum arc_space_type {
123 ARC_SPACE_DATA,
124 ARC_SPACE_META,
125 ARC_SPACE_HDRS,
126 ARC_SPACE_L2HDRS,
127 ARC_SPACE_OTHER,
128 ARC_SPACE_NUMTYPES
129 } arc_space_type_t;
130
131 void arc_space_consume(uint64_t space, arc_space_type_t type);
132 void arc_space_return(uint64_t space, arc_space_type_t type);
133 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
134 arc_buf_contents_t type);
135 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
136 void arc_return_buf(arc_buf_t *buf, void *tag);
137 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
138 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
139 boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
140 int arc_buf_size(arc_buf_t *buf);
141 void arc_release(arc_buf_t *buf, void *tag);
142 int arc_released(arc_buf_t *buf);
143 void arc_buf_freeze(arc_buf_t *buf);
144 void arc_buf_thaw(arc_buf_t *buf);
145 boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
146 #ifdef ZFS_DEBUG
147 int arc_referenced(arc_buf_t *buf);
148 #endif
149
150 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
151 arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
152 arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
153 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
154 blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
155 const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone,
156 arc_done_func_t *done, void *private, zio_priority_t priority,
157 int zio_flags, const zbookmark_phys_t *zb);
158 void arc_freed(spa_t *spa, const blkptr_t *bp);
159
160 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
161 boolean_t arc_clear_callback(arc_buf_t *buf);
162
163 void arc_flush(spa_t *spa, boolean_t retry);
164 void arc_tempreserve_clear(uint64_t reserve);
165 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
166
167 void arc_init(void);
168 void arc_fini(void);
169
170 /*
171 * Level 2 ARC
172 */
173
174 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
175 void l2arc_remove_vdev(vdev_t *vd);
176 boolean_t l2arc_vdev_present(vdev_t *vd);
177 void l2arc_init(void);
178 void l2arc_fini(void);
179 void l2arc_start(void);
180 void l2arc_stop(void);
181
182 #ifndef _KERNEL
183 extern boolean_t arc_watch;
184 extern int arc_procfd;
185 #endif
186
187 #ifdef __cplusplus
188 }
189 #endif
190
191 #endif /* _SYS_ARC_H */