xref: /freebsd/sys/contrib/openzfs/include/sys/arc.h (revision 17aab35a77a1b1bf02fc85bb8ffadccb0ca5006d)
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 https://opensource.org/licenses/CDDL-1.0.
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	UINT64_MAX
48 
49 /*
50  * ZFS gets very unhappy when the maximum ARC size is smaller than the maximum
51  * block size and a larger block is written.  To leave some safety margin, we
52  * limit the minimum for zfs_arc_max to the maximium transaction size.
53  */
54 #define	MIN_ARC_MAX	DMU_MAX_ACCESS
55 
56 #define	HDR_SET_LSIZE(hdr, x) do { \
57 	ASSERT(IS_P2ALIGNED(x, 1U << SPA_MINBLOCKSHIFT)); \
58 	(hdr)->b_lsize = ((x) >> SPA_MINBLOCKSHIFT); \
59 } while (0)
60 
61 #define	HDR_SET_PSIZE(hdr, x) do { \
62 	ASSERT(IS_P2ALIGNED((x), 1U << SPA_MINBLOCKSHIFT)); \
63 	(hdr)->b_psize = ((x) >> SPA_MINBLOCKSHIFT); \
64 } while (0)
65 
66 /* The l2size in the header is only used by L2 cache */
67 #define	HDR_SET_L2SIZE(hdr, x) do { \
68 	ASSERT(IS_P2ALIGNED((x), 1U << SPA_MINBLOCKSHIFT)); \
69 	(hdr)->b_l2size = ((x) >> SPA_MINBLOCKSHIFT); \
70 } while (0)
71 
72 #define	HDR_GET_LSIZE(hdr)	((hdr)->b_lsize << SPA_MINBLOCKSHIFT)
73 #define	HDR_GET_PSIZE(hdr)	((hdr)->b_psize << SPA_MINBLOCKSHIFT)
74 #define	HDR_GET_L2SIZE(hdr)	((hdr)->b_l2size << SPA_MINBLOCKSHIFT)
75 
76 typedef struct arc_buf_hdr arc_buf_hdr_t;
77 typedef struct arc_buf arc_buf_t;
78 typedef struct arc_prune arc_prune_t;
79 
80 /*
81  * Because the ARC can store encrypted data, errors (not due to bugs) may arise
82  * while transforming data into its desired format - specifically, when
83  * decrypting, the key may not be present, or the HMAC may not be correct
84  * which signifies deliberate tampering with the on-disk state
85  * (assuming that the checksum was correct). If any error occurs, the "buf"
86  * parameter will be NULL.
87  */
88 typedef void arc_read_done_func_t(zio_t *zio, const zbookmark_phys_t *zb,
89     const blkptr_t *bp, arc_buf_t *buf, void *priv);
90 typedef void arc_write_done_func_t(zio_t *zio, arc_buf_t *buf, void *priv);
91 typedef void arc_prune_func_t(uint64_t bytes, void *priv);
92 
93 /* Shared module parameters */
94 extern uint_t zfs_arc_average_blocksize;
95 extern int l2arc_exclude_special;
96 
97 /* generic arc_done_func_t's which you can use */
98 arc_read_done_func_t arc_bcopy_func;
99 arc_read_done_func_t arc_getbuf_func;
100 
101 /* generic arc_prune_func_t wrapper for callbacks */
102 struct arc_prune {
103 	arc_prune_func_t	*p_pfunc;
104 	void			*p_private;
105 	uint64_t		p_adjust;
106 	list_node_t		p_node;
107 	zfs_refcount_t		p_refcnt;
108 };
109 
110 typedef enum arc_strategy {
111 	ARC_STRATEGY_META_ONLY		= 0, /* Evict only meta data buffers */
112 	ARC_STRATEGY_META_BALANCED	= 1, /* Evict data buffers if needed */
113 } arc_strategy_t;
114 
115 typedef enum arc_flags
116 {
117 	/*
118 	 * Public flags that can be passed into the ARC by external consumers.
119 	 */
120 	ARC_FLAG_WAIT			= 1 << 0,	/* perform sync I/O */
121 	ARC_FLAG_NOWAIT			= 1 << 1,	/* perform async I/O */
122 	ARC_FLAG_PREFETCH		= 1 << 2,	/* I/O is a prefetch */
123 	ARC_FLAG_CACHED			= 1 << 3,	/* I/O was in cache */
124 	ARC_FLAG_L2CACHE		= 1 << 4,	/* cache in L2ARC */
125 	ARC_FLAG_UNCACHED		= 1 << 5,	/* evict after use */
126 	ARC_FLAG_PRESCIENT_PREFETCH	= 1 << 6,	/* long min lifespan */
127 
128 	/*
129 	 * Private ARC flags.  These flags are private ARC only flags that
130 	 * will show up in b_flags in the arc_buf_hdr_t. These flags should
131 	 * only be set by ARC code.
132 	 */
133 	ARC_FLAG_IN_HASH_TABLE		= 1 << 7,	/* buffer is hashed */
134 	ARC_FLAG_IO_IN_PROGRESS		= 1 << 8,	/* I/O in progress */
135 	ARC_FLAG_IO_ERROR		= 1 << 9,	/* I/O failed for buf */
136 	ARC_FLAG_INDIRECT		= 1 << 10,	/* indirect block */
137 	/* Indicates that block was read with ASYNC priority. */
138 	ARC_FLAG_PRIO_ASYNC_READ	= 1 << 11,
139 	ARC_FLAG_L2_WRITING		= 1 << 12,	/* write in progress */
140 	ARC_FLAG_L2_EVICTED		= 1 << 13,	/* evicted during I/O */
141 	ARC_FLAG_L2_WRITE_HEAD		= 1 << 14,	/* head of write list */
142 	/*
143 	 * Encrypted or authenticated on disk (may be plaintext in memory).
144 	 * This header has b_crypt_hdr allocated. Does not include indirect
145 	 * blocks with checksums of MACs which will also have their X
146 	 * (encrypted) bit set in the bp.
147 	 */
148 	ARC_FLAG_PROTECTED		= 1 << 15,
149 	/* data has not been authenticated yet */
150 	ARC_FLAG_NOAUTH			= 1 << 16,
151 	/* indicates that the buffer contains metadata (otherwise, data) */
152 	ARC_FLAG_BUFC_METADATA		= 1 << 17,
153 
154 	/* Flags specifying whether optional hdr struct fields are defined */
155 	ARC_FLAG_HAS_L1HDR		= 1 << 18,
156 	ARC_FLAG_HAS_L2HDR		= 1 << 19,
157 
158 	/*
159 	 * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
160 	 * This allows the l2arc to use the blkptr's checksum to verify
161 	 * the data without having to store the checksum in the hdr.
162 	 */
163 	ARC_FLAG_COMPRESSED_ARC		= 1 << 20,
164 	ARC_FLAG_SHARED_DATA		= 1 << 21,
165 
166 	/*
167 	 * Fail this arc_read() (with ENOENT) if the data is not already present
168 	 * in cache.
169 	 */
170 	ARC_FLAG_CACHED_ONLY		= 1 << 22,
171 
172 	/*
173 	 * Don't instantiate an arc_buf_t for arc_read_done.
174 	 */
175 	ARC_FLAG_NO_BUF			= 1 << 23,
176 
177 	/*
178 	 * The arc buffer's compression mode is stored in the top 7 bits of the
179 	 * flags field, so these dummy flags are included so that MDB can
180 	 * interpret the enum properly.
181 	 */
182 	ARC_FLAG_COMPRESS_0		= 1 << 24,
183 	ARC_FLAG_COMPRESS_1		= 1 << 25,
184 	ARC_FLAG_COMPRESS_2		= 1 << 26,
185 	ARC_FLAG_COMPRESS_3		= 1 << 27,
186 	ARC_FLAG_COMPRESS_4		= 1 << 28,
187 	ARC_FLAG_COMPRESS_5		= 1 << 29,
188 	ARC_FLAG_COMPRESS_6		= 1 << 30
189 } arc_flags_t;
190 
191 typedef enum arc_buf_flags {
192 	ARC_BUF_FLAG_SHARED		= 1 << 0,
193 	ARC_BUF_FLAG_COMPRESSED		= 1 << 1,
194 	/*
195 	 * indicates whether this arc_buf_t is encrypted, regardless of
196 	 * state on-disk
197 	 */
198 	ARC_BUF_FLAG_ENCRYPTED		= 1 << 2
199 } arc_buf_flags_t;
200 
201 struct arc_buf {
202 	arc_buf_hdr_t		*b_hdr;
203 	arc_buf_t		*b_next;
204 	void			*b_data;
205 	arc_buf_flags_t		b_flags;
206 };
207 
208 typedef enum arc_buf_contents {
209 	ARC_BUFC_DATA,				/* buffer contains data */
210 	ARC_BUFC_METADATA,			/* buffer contains metadata */
211 	ARC_BUFC_NUMTYPES
212 } arc_buf_contents_t;
213 
214 /*
215  * The following breakdowns of arc_size exist for kstat only.
216  */
217 typedef enum arc_space_type {
218 	ARC_SPACE_DATA,
219 	ARC_SPACE_META,
220 	ARC_SPACE_HDRS,
221 	ARC_SPACE_L2HDRS,
222 	ARC_SPACE_DBUF,
223 	ARC_SPACE_DNODE,
224 	ARC_SPACE_BONUS,
225 	ARC_SPACE_ABD_CHUNK_WASTE,
226 	ARC_SPACE_NUMTYPES
227 } arc_space_type_t;
228 
229 typedef enum arc_state_type {
230 	ARC_STATE_ANON,
231 	ARC_STATE_MRU,
232 	ARC_STATE_MRU_GHOST,
233 	ARC_STATE_MFU,
234 	ARC_STATE_MFU_GHOST,
235 	ARC_STATE_L2C_ONLY,
236 	ARC_STATE_UNCACHED,
237 	ARC_STATE_NUMTYPES
238 } arc_state_type_t;
239 
240 typedef struct arc_buf_info {
241 	arc_state_type_t	abi_state_type;
242 	arc_buf_contents_t	abi_state_contents;
243 	uint32_t		abi_flags;
244 	uint32_t		abi_bufcnt;
245 	uint64_t		abi_size;
246 	uint64_t		abi_spa;
247 	uint64_t		abi_access;
248 	uint32_t		abi_mru_hits;
249 	uint32_t		abi_mru_ghost_hits;
250 	uint32_t		abi_mfu_hits;
251 	uint32_t		abi_mfu_ghost_hits;
252 	uint32_t		abi_l2arc_hits;
253 	uint32_t		abi_holds;
254 	uint64_t		abi_l2arc_dattr;
255 	uint64_t		abi_l2arc_asize;
256 	enum zio_compress	abi_l2arc_compress;
257 } arc_buf_info_t;
258 
259 /*
260  * Flags returned by arc_cached; describes which part of the arc
261  * the block is cached in.
262  */
263 #define	ARC_CACHED_EMBEDDED	(1U << 0)
264 #define	ARC_CACHED_IN_L1	(1U << 1)
265 #define	ARC_CACHED_IN_MRU	(1U << 2)
266 #define	ARC_CACHED_IN_MFU	(1U << 3)
267 #define	ARC_CACHED_IN_L2	(1U << 4)
268 
269 void arc_space_consume(uint64_t space, arc_space_type_t type);
270 void arc_space_return(uint64_t space, arc_space_type_t type);
271 boolean_t arc_is_metadata(arc_buf_t *buf);
272 boolean_t arc_is_encrypted(arc_buf_t *buf);
273 boolean_t arc_is_unauthenticated(arc_buf_t *buf);
274 enum zio_compress arc_get_compression(arc_buf_t *buf);
275 void arc_get_raw_params(arc_buf_t *buf, boolean_t *byteorder, uint8_t *salt,
276     uint8_t *iv, uint8_t *mac);
277 int arc_untransform(arc_buf_t *buf, spa_t *spa, const zbookmark_phys_t *zb,
278     boolean_t in_place);
279 void arc_convert_to_raw(arc_buf_t *buf, uint64_t dsobj, boolean_t byteorder,
280     dmu_object_type_t ot, const uint8_t *salt, const uint8_t *iv,
281     const uint8_t *mac);
282 arc_buf_t *arc_alloc_buf(spa_t *spa, const void *tag, arc_buf_contents_t type,
283     int32_t size);
284 arc_buf_t *arc_alloc_compressed_buf(spa_t *spa, const void *tag,
285     uint64_t psize, uint64_t lsize, enum zio_compress compression_type,
286     uint8_t complevel);
287 arc_buf_t *arc_alloc_raw_buf(spa_t *spa, const void *tag, uint64_t dsobj,
288     boolean_t byteorder, const uint8_t *salt, const uint8_t *iv,
289     const uint8_t *mac, dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
290     enum zio_compress compression_type, uint8_t complevel);
291 uint8_t arc_get_complevel(arc_buf_t *buf);
292 arc_buf_t *arc_loan_buf(spa_t *spa, boolean_t is_metadata, int size);
293 arc_buf_t *arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize,
294     enum zio_compress compression_type, uint8_t complevel);
295 arc_buf_t *arc_loan_raw_buf(spa_t *spa, uint64_t dsobj, boolean_t byteorder,
296     const uint8_t *salt, const uint8_t *iv, const uint8_t *mac,
297     dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
298     enum zio_compress compression_type, uint8_t complevel);
299 void arc_return_buf(arc_buf_t *buf, const void *tag);
300 void arc_loan_inuse_buf(arc_buf_t *buf, const void *tag);
301 void arc_buf_destroy(arc_buf_t *buf, const void *tag);
302 void arc_buf_info(arc_buf_t *buf, arc_buf_info_t *abi, int state_index);
303 uint64_t arc_buf_size(arc_buf_t *buf);
304 uint64_t arc_buf_lsize(arc_buf_t *buf);
305 void arc_buf_access(arc_buf_t *buf);
306 void arc_release(arc_buf_t *buf, const void *tag);
307 int arc_released(arc_buf_t *buf);
308 void arc_buf_sigsegv(int sig, siginfo_t *si, void *unused);
309 void arc_buf_freeze(arc_buf_t *buf);
310 void arc_buf_thaw(arc_buf_t *buf);
311 #ifdef ZFS_DEBUG
312 int arc_referenced(arc_buf_t *buf);
313 #else
314 #define	arc_referenced(buf) ((void) sizeof (buf), 0)
315 #endif
316 
317 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
318     arc_read_done_func_t *done, void *priv, zio_priority_t priority,
319     int flags, arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
320 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
321     arc_buf_t *buf, boolean_t uncached, boolean_t l2arc, const zio_prop_t *zp,
322     arc_write_done_func_t *ready, arc_write_done_func_t *child_ready,
323     arc_write_done_func_t *done, void *priv, zio_priority_t priority,
324     int zio_flags, const zbookmark_phys_t *zb);
325 
326 arc_prune_t *arc_add_prune_callback(arc_prune_func_t *func, void *priv);
327 void arc_remove_prune_callback(arc_prune_t *p);
328 void arc_freed(spa_t *spa, const blkptr_t *bp);
329 int arc_cached(spa_t *spa, const blkptr_t *bp);
330 
331 void arc_flush(spa_t *spa, boolean_t retry);
332 void arc_flush_async(spa_t *spa);
333 void arc_tempreserve_clear(uint64_t reserve);
334 int arc_tempreserve_space(spa_t *spa, uint64_t reserve, uint64_t txg);
335 boolean_t arc_async_flush_guid_inuse(uint64_t load_guid);
336 
337 uint64_t arc_all_memory(void);
338 uint64_t arc_default_max(uint64_t min, uint64_t allmem);
339 uint64_t arc_target_bytes(void);
340 void arc_set_limits(uint64_t);
341 void arc_init(void);
342 void arc_fini(void);
343 
344 /*
345  * Level 2 ARC
346  */
347 
348 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
349 void l2arc_remove_vdev(vdev_t *vd);
350 boolean_t l2arc_vdev_present(vdev_t *vd);
351 void l2arc_rebuild_vdev(vdev_t *vd, boolean_t reopen);
352 boolean_t l2arc_range_check_overlap(uint64_t bottom, uint64_t top,
353     uint64_t check);
354 void l2arc_init(void);
355 void l2arc_fini(void);
356 void l2arc_start(void);
357 void l2arc_stop(void);
358 void l2arc_spa_rebuild_start(spa_t *spa);
359 void l2arc_spa_rebuild_stop(spa_t *spa);
360 
361 #ifndef _KERNEL
362 extern boolean_t arc_watch;
363 #endif
364 
365 #ifdef	__cplusplus
366 }
367 #endif
368 
369 #endif /* _SYS_ARC_H */
370