arc.h revision 307266 
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 */
26
27#ifndef	_SYS_ARC_H
28#define	_SYS_ARC_H
29
30#include <sys/zfs_context.h>
31
32#ifdef	__cplusplus
33extern "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
59typedef struct arc_buf_hdr arc_buf_hdr_t;
60typedef struct arc_buf arc_buf_t;
61typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *priv);
62
63/* generic arc_done_func_t's which you can use */
64arc_done_func_t arc_bcopy_func;
65arc_done_func_t arc_getbuf_func;
66
67extern int zfs_arc_num_sublists_per_state;
68
69typedef enum arc_flags
70{
71	/*
72	 * Public flags that can be passed into the ARC by external consumers.
73	 */
74	ARC_FLAG_WAIT			= 1 << 0,	/* perform sync I/O */
75	ARC_FLAG_NOWAIT			= 1 << 1,	/* perform async I/O */
76	ARC_FLAG_PREFETCH		= 1 << 2,	/* I/O is a prefetch */
77	ARC_FLAG_CACHED			= 1 << 3,	/* I/O was in cache */
78	ARC_FLAG_L2CACHE		= 1 << 4,	/* cache in L2ARC */
79	ARC_FLAG_PREDICTIVE_PREFETCH	= 1 << 5,	/* I/O from zfetch */
80
81	/*
82	 * Private ARC flags.  These flags are private ARC only flags that
83	 * will show up in b_flags in the arc_hdr_buf_t. These flags should
84	 * only be set by ARC code.
85	 */
86	ARC_FLAG_IN_HASH_TABLE		= 1 << 6,	/* buffer is hashed */
87	ARC_FLAG_IO_IN_PROGRESS		= 1 << 7,	/* I/O in progress */
88	ARC_FLAG_IO_ERROR		= 1 << 8,	/* I/O failed for buf */
89	ARC_FLAG_INDIRECT		= 1 << 9,	/* indirect block */
90	/* Indicates that block was read with ASYNC priority. */
91	ARC_FLAG_PRIO_ASYNC_READ	= 1 << 10,
92	ARC_FLAG_L2_WRITING		= 1 << 11,	/* write in progress */
93	ARC_FLAG_L2_EVICTED		= 1 << 12,	/* evicted during I/O */
94	ARC_FLAG_L2_WRITE_HEAD		= 1 << 13,	/* head of write list */
95	/* indicates that the buffer contains metadata (otherwise, data) */
96	ARC_FLAG_BUFC_METADATA		= 1 << 14,
97
98	/* Flags specifying whether optional hdr struct fields are defined */
99	ARC_FLAG_HAS_L1HDR		= 1 << 15,
100	ARC_FLAG_HAS_L2HDR		= 1 << 16,
101
102	/*
103	 * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
104	 * This allows the l2arc to use the blkptr's checksum to verify
105	 * the data without having to store the checksum in the hdr.
106	 */
107	ARC_FLAG_COMPRESSED_ARC		= 1 << 17,
108	ARC_FLAG_SHARED_DATA		= 1 << 18,
109
110	/*
111	 * The arc buffer's compression mode is stored in the top 7 bits of the
112	 * flags field, so these dummy flags are included so that MDB can
113	 * interpret the enum properly.
114	 */
115	ARC_FLAG_COMPRESS_0		= 1 << 24,
116	ARC_FLAG_COMPRESS_1		= 1 << 25,
117	ARC_FLAG_COMPRESS_2		= 1 << 26,
118	ARC_FLAG_COMPRESS_3		= 1 << 27,
119	ARC_FLAG_COMPRESS_4		= 1 << 28,
120	ARC_FLAG_COMPRESS_5		= 1 << 29,
121	ARC_FLAG_COMPRESS_6		= 1 << 30
122
123} arc_flags_t;
124
125struct arc_buf {
126	arc_buf_hdr_t		*b_hdr;
127	arc_buf_t		*b_next;
128	kmutex_t		b_evict_lock;
129	void			*b_data;
130};
131
132typedef enum arc_buf_contents {
133	ARC_BUFC_INVALID,			/* invalid type */
134	ARC_BUFC_DATA,				/* buffer contains data */
135	ARC_BUFC_METADATA,			/* buffer contains metadata */
136	ARC_BUFC_NUMTYPES
137} arc_buf_contents_t;
138
139/*
140 * The following breakdows of arc_size exist for kstat only.
141 */
142typedef enum arc_space_type {
143	ARC_SPACE_DATA,
144	ARC_SPACE_META,
145	ARC_SPACE_HDRS,
146	ARC_SPACE_L2HDRS,
147	ARC_SPACE_OTHER,
148	ARC_SPACE_NUMTYPES
149} arc_space_type_t;
150
151void arc_space_consume(uint64_t space, arc_space_type_t type);
152void arc_space_return(uint64_t space, arc_space_type_t type);
153arc_buf_t *arc_alloc_buf(spa_t *spa, int32_t size, void *tag,
154    arc_buf_contents_t type);
155arc_buf_t *arc_loan_buf(spa_t *spa, int size);
156void arc_return_buf(arc_buf_t *buf, void *tag);
157void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
158void arc_buf_destroy(arc_buf_t *buf, void *tag);
159int arc_buf_size(arc_buf_t *buf);
160void arc_release(arc_buf_t *buf, void *tag);
161int arc_released(arc_buf_t *buf);
162void arc_buf_freeze(arc_buf_t *buf);
163void arc_buf_thaw(arc_buf_t *buf);
164#ifdef ZFS_DEBUG
165int arc_referenced(arc_buf_t *buf);
166#endif
167
168int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
169    arc_done_func_t *done, void *priv, zio_priority_t priority, int flags,
170    arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
171zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
172    blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
173    arc_done_func_t *ready, arc_done_func_t *child_ready,
174    arc_done_func_t *physdone, arc_done_func_t *done,
175    void *priv, zio_priority_t priority, int zio_flags,
176    const zbookmark_phys_t *zb);
177void arc_freed(spa_t *spa, const blkptr_t *bp);
178
179void arc_flush(spa_t *spa, boolean_t retry);
180void arc_tempreserve_clear(uint64_t reserve);
181int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
182
183uint64_t arc_max_bytes(void);
184void arc_init(void);
185void arc_fini(void);
186
187/*
188 * Level 2 ARC
189 */
190
191void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
192void l2arc_remove_vdev(vdev_t *vd);
193boolean_t l2arc_vdev_present(vdev_t *vd);
194void l2arc_init(void);
195void l2arc_fini(void);
196void l2arc_start(void);
197void l2arc_stop(void);
198
199#ifdef illumos
200#ifndef _KERNEL
201extern boolean_t arc_watch;
202extern int arc_procfd;
203#endif
204#endif /* illumos */
205
206#ifdef	__cplusplus
207}
208#endif
209
210#endif /* _SYS_ARC_H */
211