xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/arc.h (revision 6f1fa39e3cf1b335f342bbca41590e9d76ab29b7)
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 
62 /*
63  * Because the ARC can store encrypted data, errors (not due to bugs) may arise
64  * while transforming data into its desired format - specifically, when
65  * decrypting, the key may not be present, or the HMAC may not be correct
66  * which signifies deliberate tampering with the on-disk state
67  * (assuming that the checksum was correct). The "error" parameter will be
68  * nonzero in this case, even if there is no associated zio.
69  */
70 typedef void arc_read_done_func_t(zio_t *zio, const zbookmark_phys_t *zb,
71     const blkptr_t *bp, arc_buf_t *buf, void *priv);
72 typedef void arc_write_done_func_t(zio_t *zio, arc_buf_t *buf, void *priv);
73 
74 /* generic arc_done_func_t's which you can use */
75 arc_read_done_func_t arc_bcopy_func;
76 arc_read_done_func_t arc_getbuf_func;
77 
78 typedef enum arc_flags
79 {
80 	/*
81 	 * Public flags that can be passed into the ARC by external consumers.
82 	 */
83 	ARC_FLAG_WAIT			= 1 << 0,	/* perform sync I/O */
84 	ARC_FLAG_NOWAIT			= 1 << 1,	/* perform async I/O */
85 	ARC_FLAG_PREFETCH		= 1 << 2,	/* I/O is a prefetch */
86 	ARC_FLAG_CACHED			= 1 << 3,	/* I/O was in cache */
87 	ARC_FLAG_L2CACHE		= 1 << 4,	/* cache in L2ARC */
88 	ARC_FLAG_PREDICTIVE_PREFETCH	= 1 << 5,	/* I/O from zfetch */
89 	ARC_FLAG_PRESCIENT_PREFETCH	= 1 << 6,	/* long min lifespan */
90 
91 	/*
92 	 * Private ARC flags.  These flags are private ARC only flags that
93 	 * will show up in b_flags in the arc_hdr_buf_t. These flags should
94 	 * only be set by ARC code.
95 	 */
96 	ARC_FLAG_IN_HASH_TABLE		= 1 << 7,	/* buffer is hashed */
97 	ARC_FLAG_IO_IN_PROGRESS		= 1 << 8,	/* I/O in progress */
98 	ARC_FLAG_IO_ERROR		= 1 << 9,	/* I/O failed for buf */
99 	ARC_FLAG_INDIRECT		= 1 << 10,	/* indirect block */
100 	/* Indicates that block was read with ASYNC priority. */
101 	ARC_FLAG_PRIO_ASYNC_READ	= 1 << 11,
102 	ARC_FLAG_L2_WRITING		= 1 << 12,	/* write in progress */
103 	ARC_FLAG_L2_EVICTED		= 1 << 13,	/* evicted during I/O */
104 	ARC_FLAG_L2_WRITE_HEAD		= 1 << 14,	/* head of write list */
105 	/*
106 	 * Encrypted or authenticated on disk (may be plaintext in memory).
107 	 * This header has b_crypt_hdr allocated. Does not include indirect
108 	 * blocks with checksums of MACs which will also have their X
109 	 * (encrypted) bit set in the bp.
110 	 */
111 	ARC_FLAG_PROTECTED		= 1 << 15,
112 	/* data has not been authenticated yet */
113 	ARC_FLAG_NOAUTH			= 1 << 16,
114 	/* indicates that the buffer contains metadata (otherwise, data) */
115 	ARC_FLAG_BUFC_METADATA		= 1 << 17,
116 
117 	/* Flags specifying whether optional hdr struct fields are defined */
118 	ARC_FLAG_HAS_L1HDR		= 1 << 18,
119 	ARC_FLAG_HAS_L2HDR		= 1 << 19,
120 
121 	/*
122 	 * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
123 	 * This allows the l2arc to use the blkptr's checksum to verify
124 	 * the data without having to store the checksum in the hdr.
125 	 */
126 	ARC_FLAG_COMPRESSED_ARC		= 1 << 20,
127 	ARC_FLAG_SHARED_DATA		= 1 << 21,
128 
129 	/*
130 	 * The arc buffer's compression mode is stored in the top 7 bits of the
131 	 * flags field, so these dummy flags are included so that MDB can
132 	 * interpret the enum properly.
133 	 */
134 	ARC_FLAG_COMPRESS_0		= 1 << 24,
135 	ARC_FLAG_COMPRESS_1		= 1 << 25,
136 	ARC_FLAG_COMPRESS_2		= 1 << 26,
137 	ARC_FLAG_COMPRESS_3		= 1 << 27,
138 	ARC_FLAG_COMPRESS_4		= 1 << 28,
139 	ARC_FLAG_COMPRESS_5		= 1 << 29,
140 	ARC_FLAG_COMPRESS_6		= 1 << 30
141 
142 } arc_flags_t;
143 
144 typedef enum arc_buf_flags {
145 	ARC_BUF_FLAG_SHARED		= 1 << 0,
146 	ARC_BUF_FLAG_COMPRESSED		= 1 << 1,
147 	/*
148 	 * indicates whether this arc_buf_t is encrypted, regardless of
149 	 * state on-disk
150 	 */
151 	ARC_BUF_FLAG_ENCRYPTED		= 1 << 2
152 } arc_buf_flags_t;
153 
154 struct arc_buf {
155 	arc_buf_hdr_t		*b_hdr;
156 	arc_buf_t		*b_next;
157 	kmutex_t		b_evict_lock;
158 	void			*b_data;
159 	arc_buf_flags_t		b_flags;
160 };
161 
162 typedef enum arc_buf_contents {
163 	ARC_BUFC_INVALID,			/* invalid type */
164 	ARC_BUFC_DATA,				/* buffer contains data */
165 	ARC_BUFC_METADATA,			/* buffer contains metadata */
166 	ARC_BUFC_NUMTYPES
167 } arc_buf_contents_t;
168 
169 /*
170  * The following breakdows of arc_size exist for kstat only.
171  */
172 typedef enum arc_space_type {
173 	ARC_SPACE_DATA,
174 	ARC_SPACE_META,
175 	ARC_SPACE_HDRS,
176 	ARC_SPACE_L2HDRS,
177 	ARC_SPACE_OTHER,
178 	ARC_SPACE_BONUS,
179 	ARC_SPACE_NUMTYPES
180 } arc_space_type_t;
181 
182 typedef enum arc_state_type {
183 	ARC_STATE_ANON,
184 	ARC_STATE_MRU,
185 	ARC_STATE_MRU_GHOST,
186 	ARC_STATE_MFU,
187 	ARC_STATE_MFU_GHOST,
188 	ARC_STATE_L2C_ONLY,
189 	ARC_STATE_NUMTYPES
190 } arc_state_type_t;
191 
192 void arc_space_consume(uint64_t space, arc_space_type_t type);
193 void arc_space_return(uint64_t space, arc_space_type_t type);
194 boolean_t arc_is_metadata(arc_buf_t *buf);
195 boolean_t arc_is_encrypted(arc_buf_t *buf);
196 boolean_t arc_is_unauthenticated(arc_buf_t *buf);
197 enum zio_compress arc_get_compression(arc_buf_t *buf);
198 void arc_get_raw_params(arc_buf_t *buf, boolean_t *byteorder, uint8_t *salt,
199     uint8_t *iv, uint8_t *mac);
200 int arc_untransform(arc_buf_t *buf, spa_t *spa, const zbookmark_phys_t *zb,
201     boolean_t in_place);
202 void arc_convert_to_raw(arc_buf_t *buf, uint64_t dsobj, boolean_t byteorder,
203     dmu_object_type_t ot, const uint8_t *salt, const uint8_t *iv,
204     const uint8_t *mac);
205 arc_buf_t *arc_alloc_buf(spa_t *spa, void *tag, arc_buf_contents_t type,
206     int32_t size);
207 arc_buf_t *arc_alloc_compressed_buf(spa_t *spa, void *tag,
208     uint64_t psize, uint64_t lsize, enum zio_compress compression_type);
209 arc_buf_t *arc_alloc_raw_buf(spa_t *spa, void *tag, uint64_t dsobj,
210     boolean_t byteorder, const uint8_t *salt, const uint8_t *iv,
211     const uint8_t *mac, dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
212     enum zio_compress compression_type);
213 arc_buf_t *arc_loan_buf(spa_t *spa, boolean_t is_metadata, int size);
214 arc_buf_t *arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize,
215     enum zio_compress compression_type);
216 arc_buf_t *arc_loan_raw_buf(spa_t *spa, uint64_t dsobj, boolean_t byteorder,
217     const uint8_t *salt, const uint8_t *iv, const uint8_t *mac,
218     dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
219     enum zio_compress compression_type);
220 void arc_return_buf(arc_buf_t *buf, void *tag);
221 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
222 void arc_buf_destroy(arc_buf_t *buf, void *tag);
223 int arc_buf_size(arc_buf_t *buf);
224 int arc_buf_lsize(arc_buf_t *buf);
225 void arc_buf_access(arc_buf_t *buf);
226 void arc_release(arc_buf_t *buf, void *tag);
227 int arc_released(arc_buf_t *buf);
228 void arc_buf_freeze(arc_buf_t *buf);
229 void arc_buf_thaw(arc_buf_t *buf);
230 #ifdef ZFS_DEBUG
231 int arc_referenced(arc_buf_t *buf);
232 #endif
233 
234 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
235     arc_read_done_func_t *done, void *private, zio_priority_t priority,
236     int flags, arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
237 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
238     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
239     arc_write_done_func_t *ready, arc_write_done_func_t *child_ready,
240     arc_write_done_func_t *physdone, arc_write_done_func_t *done,
241     void *private, zio_priority_t priority, int zio_flags,
242     const zbookmark_phys_t *zb);
243 void arc_freed(spa_t *spa, const blkptr_t *bp);
244 
245 void arc_flush(spa_t *spa, boolean_t retry);
246 void arc_tempreserve_clear(uint64_t reserve);
247 int arc_tempreserve_space(spa_t *spa, uint64_t reserve, uint64_t txg);
248 
249 uint64_t arc_all_memory(void);
250 uint64_t arc_max_bytes(void);
251 void arc_init(void);
252 void arc_fini(void);
253 
254 /*
255  * Level 2 ARC
256  */
257 
258 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
259 void l2arc_remove_vdev(vdev_t *vd);
260 boolean_t l2arc_vdev_present(vdev_t *vd);
261 void l2arc_rebuild_vdev(vdev_t *vd, boolean_t reopen);
262 boolean_t l2arc_range_check_overlap(uint64_t bottom, uint64_t top,
263     uint64_t check);
264 void l2arc_init(void);
265 void l2arc_fini(void);
266 void l2arc_start(void);
267 void l2arc_stop(void);
268 void l2arc_spa_rebuild_start(spa_t *spa);
269 
270 #ifndef _KERNEL
271 extern boolean_t arc_watch;
272 extern int arc_procfd;
273 #endif
274 
275 #ifdef	__cplusplus
276 }
277 #endif
278 
279 #endif /* _SYS_ARC_H */
280