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, 2017 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 #define HDR_SET_LSIZE(hdr, x) do { \
47 ASSERT(IS_P2ALIGNED(x, 1U << SPA_MINBLOCKSHIFT)); \
48 (hdr)->b_lsize = ((x) >> SPA_MINBLOCKSHIFT); \
49 _NOTE(CONSTCOND) } while (0)
50
51 #define HDR_SET_PSIZE(hdr, x) do { \
52 ASSERT(IS_P2ALIGNED((x), 1U << SPA_MINBLOCKSHIFT)); \
53 (hdr)->b_psize = ((x) >> SPA_MINBLOCKSHIFT); \
54 _NOTE(CONSTCOND) } while (0)
55
56 #define HDR_GET_LSIZE(hdr) ((hdr)->b_lsize << SPA_MINBLOCKSHIFT)
57 #define HDR_GET_PSIZE(hdr) ((hdr)->b_psize << SPA_MINBLOCKSHIFT)
58
59 typedef struct arc_buf_hdr arc_buf_hdr_t;
60 typedef struct arc_buf arc_buf_t;
61 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
62
63 /* generic arc_done_func_t's which you can use */
64 arc_done_func_t arc_bcopy_func;
65 arc_done_func_t arc_getbuf_func;
66
67 typedef enum arc_flags
68 {
69 /*
70 * Public flags that can be passed into the ARC by external consumers.
71 */
72 ARC_FLAG_WAIT = 1 << 0, /* perform sync I/O */
73 ARC_FLAG_NOWAIT = 1 << 1, /* perform async I/O */
74 ARC_FLAG_PREFETCH = 1 << 2, /* I/O is a prefetch */
75 ARC_FLAG_CACHED = 1 << 3, /* I/O was in cache */
76 ARC_FLAG_L2CACHE = 1 << 4, /* cache in L2ARC */
77 ARC_FLAG_PREDICTIVE_PREFETCH = 1 << 5, /* I/O from zfetch */
78
79 /*
80 * Private ARC flags. These flags are private ARC only flags that
81 * will show up in b_flags in the arc_hdr_buf_t. These flags should
82 * only be set by ARC code.
83 */
84 ARC_FLAG_IN_HASH_TABLE = 1 << 6, /* buffer is hashed */
85 ARC_FLAG_IO_IN_PROGRESS = 1 << 7, /* I/O in progress */
86 ARC_FLAG_IO_ERROR = 1 << 8, /* I/O failed for buf */
87 ARC_FLAG_INDIRECT = 1 << 9, /* indirect block */
88 /* Indicates that block was read with ASYNC priority. */
89 ARC_FLAG_PRIO_ASYNC_READ = 1 << 10,
90 ARC_FLAG_L2_WRITING = 1 << 11, /* write in progress */
91 ARC_FLAG_L2_EVICTED = 1 << 12, /* evicted during I/O */
92 ARC_FLAG_L2_WRITE_HEAD = 1 << 13, /* head of write list */
93 /* indicates that the buffer contains metadata (otherwise, data) */
94 ARC_FLAG_BUFC_METADATA = 1 << 14,
95
96 /* Flags specifying whether optional hdr struct fields are defined */
97 ARC_FLAG_HAS_L1HDR = 1 << 15,
98 ARC_FLAG_HAS_L2HDR = 1 << 16,
99
100 /*
101 * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
102 * This allows the l2arc to use the blkptr's checksum to verify
103 * the data without having to store the checksum in the hdr.
104 */
105 ARC_FLAG_COMPRESSED_ARC = 1 << 17,
106 ARC_FLAG_SHARED_DATA = 1 << 18,
107
108 /*
109 * The arc buffer's compression mode is stored in the top 7 bits of the
110 * flags field, so these dummy flags are included so that MDB can
111 * interpret the enum properly.
112 */
113 ARC_FLAG_COMPRESS_0 = 1 << 24,
114 ARC_FLAG_COMPRESS_1 = 1 << 25,
115 ARC_FLAG_COMPRESS_2 = 1 << 26,
116 ARC_FLAG_COMPRESS_3 = 1 << 27,
117 ARC_FLAG_COMPRESS_4 = 1 << 28,
118 ARC_FLAG_COMPRESS_5 = 1 << 29,
119 ARC_FLAG_COMPRESS_6 = 1 << 30
120
121 } arc_flags_t;
122
123 typedef enum arc_buf_flags {
124 ARC_BUF_FLAG_SHARED = 1 << 0,
125 ARC_BUF_FLAG_COMPRESSED = 1 << 1
126 } arc_buf_flags_t;
127
128 struct arc_buf {
129 arc_buf_hdr_t *b_hdr;
130 arc_buf_t *b_next;
131 kmutex_t b_evict_lock;
132 void *b_data;
133 arc_buf_flags_t b_flags;
134 };
135
136 typedef enum arc_buf_contents {
137 ARC_BUFC_INVALID, /* invalid type */
138 ARC_BUFC_DATA, /* buffer contains data */
139 ARC_BUFC_METADATA, /* buffer contains metadata */
140 ARC_BUFC_NUMTYPES
141 } arc_buf_contents_t;
142
143 /*
144 * The following breakdows of arc_size exist for kstat only.
145 */
146 typedef enum arc_space_type {
147 ARC_SPACE_DATA,
148 ARC_SPACE_META,
149 ARC_SPACE_HDRS,
150 ARC_SPACE_L2HDRS,
151 ARC_SPACE_OTHER,
152 ARC_SPACE_NUMTYPES
153 } arc_space_type_t;
154
155 void arc_space_consume(uint64_t space, arc_space_type_t type);
156 void arc_space_return(uint64_t space, arc_space_type_t type);
157 boolean_t arc_is_metadata(arc_buf_t *buf);
158 enum zio_compress arc_get_compression(arc_buf_t *buf);
159 int arc_decompress(arc_buf_t *buf);
160 arc_buf_t *arc_alloc_buf(spa_t *spa, void *tag, arc_buf_contents_t type,
161 int32_t size);
162 arc_buf_t *arc_alloc_compressed_buf(spa_t *spa, void *tag,
163 uint64_t psize, uint64_t lsize, enum zio_compress compression_type);
164 arc_buf_t *arc_loan_buf(spa_t *spa, boolean_t is_metadata, int size);
165 arc_buf_t *arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize,
166 enum zio_compress compression_type);
167 void arc_return_buf(arc_buf_t *buf, void *tag);
168 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
169 void arc_buf_destroy(arc_buf_t *buf, void *tag);
170 int arc_buf_size(arc_buf_t *buf);
171 int arc_buf_lsize(arc_buf_t *buf);
172 void arc_release(arc_buf_t *buf, void *tag);
173 int arc_released(arc_buf_t *buf);
174 void arc_buf_freeze(arc_buf_t *buf);
175 void arc_buf_thaw(arc_buf_t *buf);
176 #ifdef ZFS_DEBUG
177 int arc_referenced(arc_buf_t *buf);
178 #endif
179
180 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
181 arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
182 arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
183 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
184 blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
185 arc_done_func_t *ready, arc_done_func_t *child_ready,
186 arc_done_func_t *physdone, arc_done_func_t *done,
187 void *private, zio_priority_t priority, int zio_flags,
188 const zbookmark_phys_t *zb);
189 void arc_freed(spa_t *spa, const blkptr_t *bp);
190
191 void arc_flush(spa_t *spa, boolean_t retry);
192 void arc_tempreserve_clear(uint64_t reserve);
193 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
194
195 uint64_t arc_max_bytes(void);
196 void arc_init(void);
197 void arc_fini(void);
198
199 /*
200 * Level 2 ARC
201 */
202
203 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
204 void l2arc_remove_vdev(vdev_t *vd);
205 boolean_t l2arc_vdev_present(vdev_t *vd);
206 void l2arc_init(void);
207 void l2arc_fini(void);
208 void l2arc_start(void);
209 void l2arc_stop(void);
210
211 #ifndef _KERNEL
212 extern boolean_t arc_watch;
213 extern int arc_procfd;
214 #endif
215
216 #ifdef __cplusplus
217 }
218 #endif
219
220 #endif /* _SYS_ARC_H */