xref: /freebsd/sys/contrib/openzfs/include/sys/arc.h (revision 7cc42f6d)
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, 2016 by Delphix. All rights reserved.
24  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25  * Copyright (c) 2019, Allan Jude
26  * Copyright (c) 2019, Klara Inc.
27  */
28 
29 #ifndef	_SYS_ARC_H
30 #define	_SYS_ARC_H
31 
32 #include <sys/zfs_context.h>
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 #include <sys/zio.h>
39 #include <sys/dmu.h>
40 #include <sys/spa.h>
41 #include <sys/zfs_refcount.h>
42 
43 /*
44  * Used by arc_flush() to inform arc_evict_state() that it should evict
45  * all available buffers from the arc state being passed in.
46  */
47 #define	ARC_EVICT_ALL	-1ULL
48 
49 #define	HDR_SET_LSIZE(hdr, x) do { \
50 	ASSERT(IS_P2ALIGNED(x, 1U << SPA_MINBLOCKSHIFT)); \
51 	(hdr)->b_lsize = ((x) >> SPA_MINBLOCKSHIFT); \
52 _NOTE(CONSTCOND) } while (0)
53 
54 #define	HDR_SET_PSIZE(hdr, x) do { \
55 	ASSERT(IS_P2ALIGNED((x), 1U << SPA_MINBLOCKSHIFT)); \
56 	(hdr)->b_psize = ((x) >> SPA_MINBLOCKSHIFT); \
57 _NOTE(CONSTCOND) } while (0)
58 
59 #define	HDR_GET_LSIZE(hdr)	((hdr)->b_lsize << SPA_MINBLOCKSHIFT)
60 #define	HDR_GET_PSIZE(hdr)	((hdr)->b_psize << SPA_MINBLOCKSHIFT)
61 
62 typedef struct arc_buf_hdr arc_buf_hdr_t;
63 typedef struct arc_buf arc_buf_t;
64 typedef struct arc_prune arc_prune_t;
65 
66 /*
67  * Because the ARC can store encrypted data, errors (not due to bugs) may arise
68  * while transforming data into its desired format - specifically, when
69  * decrypting, the key may not be present, or the HMAC may not be correct
70  * which signifies deliberate tampering with the on-disk state
71  * (assuming that the checksum was correct). If any error occurs, the "buf"
72  * parameter will be NULL.
73  */
74 typedef void arc_read_done_func_t(zio_t *zio, const zbookmark_phys_t *zb,
75     const blkptr_t *bp, arc_buf_t *buf, void *priv);
76 typedef void arc_write_done_func_t(zio_t *zio, arc_buf_t *buf, void *priv);
77 typedef void arc_prune_func_t(int64_t bytes, void *priv);
78 
79 /* Shared module parameters */
80 extern int zfs_arc_average_blocksize;
81 
82 /* generic arc_done_func_t's which you can use */
83 arc_read_done_func_t arc_bcopy_func;
84 arc_read_done_func_t arc_getbuf_func;
85 
86 /* generic arc_prune_func_t wrapper for callbacks */
87 struct arc_prune {
88 	arc_prune_func_t	*p_pfunc;
89 	void			*p_private;
90 	uint64_t		p_adjust;
91 	list_node_t		p_node;
92 	zfs_refcount_t		p_refcnt;
93 };
94 
95 typedef enum arc_strategy {
96 	ARC_STRATEGY_META_ONLY		= 0, /* Evict only meta data buffers */
97 	ARC_STRATEGY_META_BALANCED	= 1, /* Evict data buffers if needed */
98 } arc_strategy_t;
99 
100 typedef enum arc_flags
101 {
102 	/*
103 	 * Public flags that can be passed into the ARC by external consumers.
104 	 */
105 	ARC_FLAG_WAIT			= 1 << 0,	/* perform sync I/O */
106 	ARC_FLAG_NOWAIT			= 1 << 1,	/* perform async I/O */
107 	ARC_FLAG_PREFETCH		= 1 << 2,	/* I/O is a prefetch */
108 	ARC_FLAG_CACHED			= 1 << 3,	/* I/O was in cache */
109 	ARC_FLAG_L2CACHE		= 1 << 4,	/* cache in L2ARC */
110 	ARC_FLAG_PREDICTIVE_PREFETCH	= 1 << 5,	/* I/O from zfetch */
111 	ARC_FLAG_PRESCIENT_PREFETCH	= 1 << 6,	/* long min lifespan */
112 
113 	/*
114 	 * Private ARC flags.  These flags are private ARC only flags that
115 	 * will show up in b_flags in the arc_hdr_buf_t. These flags should
116 	 * only be set by ARC code.
117 	 */
118 	ARC_FLAG_IN_HASH_TABLE		= 1 << 7,	/* buffer is hashed */
119 	ARC_FLAG_IO_IN_PROGRESS		= 1 << 8,	/* I/O in progress */
120 	ARC_FLAG_IO_ERROR		= 1 << 9,	/* I/O failed for buf */
121 	ARC_FLAG_INDIRECT		= 1 << 10,	/* indirect block */
122 	/* Indicates that block was read with ASYNC priority. */
123 	ARC_FLAG_PRIO_ASYNC_READ	= 1 << 11,
124 	ARC_FLAG_L2_WRITING		= 1 << 12,	/* write in progress */
125 	ARC_FLAG_L2_EVICTED		= 1 << 13,	/* evicted during I/O */
126 	ARC_FLAG_L2_WRITE_HEAD		= 1 << 14,	/* head of write list */
127 	/*
128 	 * Encrypted or authenticated on disk (may be plaintext in memory).
129 	 * This header has b_crypt_hdr allocated. Does not include indirect
130 	 * blocks with checksums of MACs which will also have their X
131 	 * (encrypted) bit set in the bp.
132 	 */
133 	ARC_FLAG_PROTECTED		= 1 << 15,
134 	/* data has not been authenticated yet */
135 	ARC_FLAG_NOAUTH			= 1 << 16,
136 	/* indicates that the buffer contains metadata (otherwise, data) */
137 	ARC_FLAG_BUFC_METADATA		= 1 << 17,
138 
139 	/* Flags specifying whether optional hdr struct fields are defined */
140 	ARC_FLAG_HAS_L1HDR		= 1 << 18,
141 	ARC_FLAG_HAS_L2HDR		= 1 << 19,
142 
143 	/*
144 	 * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
145 	 * This allows the l2arc to use the blkptr's checksum to verify
146 	 * the data without having to store the checksum in the hdr.
147 	 */
148 	ARC_FLAG_COMPRESSED_ARC		= 1 << 20,
149 	ARC_FLAG_SHARED_DATA		= 1 << 21,
150 
151 	/*
152 	 * Fail this arc_read() (with ENOENT) if the data is not already present
153 	 * in cache.
154 	 */
155 	ARC_FLAG_CACHED_ONLY		= 1 << 22,
156 
157 	/*
158 	 * The arc buffer's compression mode is stored in the top 7 bits of the
159 	 * flags field, so these dummy flags are included so that MDB can
160 	 * interpret the enum properly.
161 	 */
162 	ARC_FLAG_COMPRESS_0		= 1 << 24,
163 	ARC_FLAG_COMPRESS_1		= 1 << 25,
164 	ARC_FLAG_COMPRESS_2		= 1 << 26,
165 	ARC_FLAG_COMPRESS_3		= 1 << 27,
166 	ARC_FLAG_COMPRESS_4		= 1 << 28,
167 	ARC_FLAG_COMPRESS_5		= 1 << 29,
168 	ARC_FLAG_COMPRESS_6		= 1 << 30
169 
170 } arc_flags_t;
171 
172 typedef enum arc_buf_flags {
173 	ARC_BUF_FLAG_SHARED		= 1 << 0,
174 	ARC_BUF_FLAG_COMPRESSED		= 1 << 1,
175 	/*
176 	 * indicates whether this arc_buf_t is encrypted, regardless of
177 	 * state on-disk
178 	 */
179 	ARC_BUF_FLAG_ENCRYPTED		= 1 << 2
180 } arc_buf_flags_t;
181 
182 struct arc_buf {
183 	arc_buf_hdr_t		*b_hdr;
184 	arc_buf_t		*b_next;
185 	kmutex_t		b_evict_lock;
186 	void			*b_data;
187 	arc_buf_flags_t		b_flags;
188 };
189 
190 typedef enum arc_buf_contents {
191 	ARC_BUFC_INVALID,			/* invalid type */
192 	ARC_BUFC_DATA,				/* buffer contains data */
193 	ARC_BUFC_METADATA,			/* buffer contains metadata */
194 	ARC_BUFC_NUMTYPES
195 } arc_buf_contents_t;
196 
197 /*
198  * The following breakdowns of arc_size exist for kstat only.
199  */
200 typedef enum arc_space_type {
201 	ARC_SPACE_DATA,
202 	ARC_SPACE_META,
203 	ARC_SPACE_HDRS,
204 	ARC_SPACE_L2HDRS,
205 	ARC_SPACE_DBUF,
206 	ARC_SPACE_DNODE,
207 	ARC_SPACE_BONUS,
208 	ARC_SPACE_ABD_CHUNK_WASTE,
209 	ARC_SPACE_NUMTYPES
210 } arc_space_type_t;
211 
212 typedef enum arc_state_type {
213 	ARC_STATE_ANON,
214 	ARC_STATE_MRU,
215 	ARC_STATE_MRU_GHOST,
216 	ARC_STATE_MFU,
217 	ARC_STATE_MFU_GHOST,
218 	ARC_STATE_L2C_ONLY,
219 	ARC_STATE_NUMTYPES
220 } arc_state_type_t;
221 
222 typedef struct arc_buf_info {
223 	arc_state_type_t	abi_state_type;
224 	arc_buf_contents_t	abi_state_contents;
225 	uint32_t		abi_flags;
226 	uint32_t		abi_bufcnt;
227 	uint64_t		abi_size;
228 	uint64_t		abi_spa;
229 	uint64_t		abi_access;
230 	uint32_t		abi_mru_hits;
231 	uint32_t		abi_mru_ghost_hits;
232 	uint32_t		abi_mfu_hits;
233 	uint32_t		abi_mfu_ghost_hits;
234 	uint32_t		abi_l2arc_hits;
235 	uint32_t		abi_holds;
236 	uint64_t		abi_l2arc_dattr;
237 	uint64_t		abi_l2arc_asize;
238 	enum zio_compress	abi_l2arc_compress;
239 } arc_buf_info_t;
240 
241 void arc_space_consume(uint64_t space, arc_space_type_t type);
242 void arc_space_return(uint64_t space, arc_space_type_t type);
243 boolean_t arc_is_metadata(arc_buf_t *buf);
244 boolean_t arc_is_encrypted(arc_buf_t *buf);
245 boolean_t arc_is_unauthenticated(arc_buf_t *buf);
246 enum zio_compress arc_get_compression(arc_buf_t *buf);
247 void arc_get_raw_params(arc_buf_t *buf, boolean_t *byteorder, uint8_t *salt,
248     uint8_t *iv, uint8_t *mac);
249 int arc_untransform(arc_buf_t *buf, spa_t *spa, const zbookmark_phys_t *zb,
250     boolean_t in_place);
251 void arc_convert_to_raw(arc_buf_t *buf, uint64_t dsobj, boolean_t byteorder,
252     dmu_object_type_t ot, const uint8_t *salt, const uint8_t *iv,
253     const uint8_t *mac);
254 arc_buf_t *arc_alloc_buf(spa_t *spa, void *tag, arc_buf_contents_t type,
255     int32_t size);
256 arc_buf_t *arc_alloc_compressed_buf(spa_t *spa, void *tag,
257     uint64_t psize, uint64_t lsize, enum zio_compress compression_type,
258     uint8_t complevel);
259 arc_buf_t *arc_alloc_raw_buf(spa_t *spa, void *tag, uint64_t dsobj,
260     boolean_t byteorder, const uint8_t *salt, const uint8_t *iv,
261     const uint8_t *mac, dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
262     enum zio_compress compression_type, uint8_t complevel);
263 uint8_t arc_get_complevel(arc_buf_t *buf);
264 arc_buf_t *arc_loan_buf(spa_t *spa, boolean_t is_metadata, int size);
265 arc_buf_t *arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize,
266     enum zio_compress compression_type, uint8_t complevel);
267 arc_buf_t *arc_loan_raw_buf(spa_t *spa, uint64_t dsobj, boolean_t byteorder,
268     const uint8_t *salt, const uint8_t *iv, const uint8_t *mac,
269     dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
270     enum zio_compress compression_type, uint8_t complevel);
271 void arc_return_buf(arc_buf_t *buf, void *tag);
272 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
273 void arc_buf_destroy(arc_buf_t *buf, void *tag);
274 void arc_buf_info(arc_buf_t *buf, arc_buf_info_t *abi, int state_index);
275 uint64_t arc_buf_size(arc_buf_t *buf);
276 uint64_t arc_buf_lsize(arc_buf_t *buf);
277 void arc_buf_access(arc_buf_t *buf);
278 void arc_release(arc_buf_t *buf, void *tag);
279 int arc_released(arc_buf_t *buf);
280 void arc_buf_sigsegv(int sig, siginfo_t *si, void *unused);
281 void arc_buf_freeze(arc_buf_t *buf);
282 void arc_buf_thaw(arc_buf_t *buf);
283 #ifdef ZFS_DEBUG
284 int arc_referenced(arc_buf_t *buf);
285 #endif
286 
287 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
288     arc_read_done_func_t *done, void *priv, zio_priority_t priority,
289     int flags, arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
290 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
291     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
292     arc_write_done_func_t *ready, arc_write_done_func_t *child_ready,
293     arc_write_done_func_t *physdone, arc_write_done_func_t *done,
294     void *priv, zio_priority_t priority, int zio_flags,
295     const zbookmark_phys_t *zb);
296 
297 arc_prune_t *arc_add_prune_callback(arc_prune_func_t *func, void *priv);
298 void arc_remove_prune_callback(arc_prune_t *p);
299 void arc_freed(spa_t *spa, const blkptr_t *bp);
300 
301 void arc_flush(spa_t *spa, boolean_t retry);
302 void arc_tempreserve_clear(uint64_t reserve);
303 int arc_tempreserve_space(spa_t *spa, uint64_t reserve, uint64_t txg);
304 
305 uint64_t arc_all_memory(void);
306 uint64_t arc_default_max(uint64_t min, uint64_t allmem);
307 uint64_t arc_target_bytes(void);
308 void arc_init(void);
309 void arc_fini(void);
310 
311 /*
312  * Level 2 ARC
313  */
314 
315 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
316 void l2arc_remove_vdev(vdev_t *vd);
317 boolean_t l2arc_vdev_present(vdev_t *vd);
318 void l2arc_rebuild_vdev(vdev_t *vd, boolean_t reopen);
319 boolean_t l2arc_range_check_overlap(uint64_t bottom, uint64_t top,
320     uint64_t check);
321 void l2arc_init(void);
322 void l2arc_fini(void);
323 void l2arc_start(void);
324 void l2arc_stop(void);
325 void l2arc_spa_rebuild_start(spa_t *spa);
326 
327 #ifndef _KERNEL
328 extern boolean_t arc_watch;
329 #endif
330 
331 #ifdef	__cplusplus
332 }
333 #endif
334 
335 #endif /* _SYS_ARC_H */
336