arc.h revision 277586 
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, 2014 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
40typedef struct arc_buf_hdr arc_buf_hdr_t;
41typedef struct arc_buf arc_buf_t;
42typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *priv);
43typedef int arc_evict_func_t(void *priv);
44
45/* generic arc_done_func_t's which you can use */
46arc_done_func_t arc_bcopy_func;
47arc_done_func_t arc_getbuf_func;
48
49typedef enum arc_flags
50{
51	/*
52	 * Public flags that can be passed into the ARC by external consumers.
53	 */
54	ARC_FLAG_NONE			= 1 << 0,	/* No flags set */
55	ARC_FLAG_WAIT			= 1 << 1,	/* perform sync I/O */
56	ARC_FLAG_NOWAIT			= 1 << 2,	/* perform async I/O */
57	ARC_FLAG_PREFETCH		= 1 << 3,	/* I/O is a prefetch */
58	ARC_FLAG_CACHED			= 1 << 4,	/* I/O was in cache */
59	ARC_FLAG_L2CACHE		= 1 << 5,	/* cache in L2ARC */
60	ARC_FLAG_L2COMPRESS		= 1 << 6,	/* compress in L2ARC */
61
62	/*
63	 * Private ARC flags.  These flags are private ARC only flags that
64	 * will show up in b_flags in the arc_hdr_buf_t. These flags should
65	 * only be set by ARC code.
66	 */
67	ARC_FLAG_IN_HASH_TABLE		= 1 << 7,	/* buffer is hashed */
68	ARC_FLAG_IO_IN_PROGRESS		= 1 << 8,	/* I/O in progress */
69	ARC_FLAG_IO_ERROR		= 1 << 9,	/* I/O failed for buf */
70	ARC_FLAG_FREED_IN_READ		= 1 << 10,	/* freed during read */
71	ARC_FLAG_BUF_AVAILABLE		= 1 << 11,	/* block not in use */
72	ARC_FLAG_INDIRECT		= 1 << 12,	/* indirect block */
73	ARC_FLAG_FREE_IN_PROGRESS	= 1 << 13,	/*  about to be freed */
74	ARC_FLAG_L2_WRITING		= 1 << 14,	/* write in progress */
75	ARC_FLAG_L2_EVICTED		= 1 << 15,	/* evicted during I/O */
76	ARC_FLAG_L2_WRITE_HEAD		= 1 << 16,	/* head of write list */
77} arc_flags_t;
78
79struct arc_buf {
80	arc_buf_hdr_t		*b_hdr;
81	arc_buf_t		*b_next;
82	kmutex_t		b_evict_lock;
83	void			*b_data;
84	arc_evict_func_t	*b_efunc;
85	void			*b_private;
86};
87
88typedef enum arc_buf_contents {
89	ARC_BUFC_DATA,				/* buffer contains data */
90	ARC_BUFC_METADATA,			/* buffer contains metadata */
91	ARC_BUFC_NUMTYPES
92} arc_buf_contents_t;
93
94/*
95 * The following breakdows of arc_size exist for kstat only.
96 */
97typedef enum arc_space_type {
98	ARC_SPACE_DATA,
99	ARC_SPACE_HDRS,
100	ARC_SPACE_L2HDRS,
101	ARC_SPACE_OTHER,
102	ARC_SPACE_NUMTYPES
103} arc_space_type_t;
104
105void arc_space_consume(uint64_t space, arc_space_type_t type);
106void arc_space_return(uint64_t space, arc_space_type_t type);
107arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
108    arc_buf_contents_t type);
109arc_buf_t *arc_loan_buf(spa_t *spa, int size);
110void arc_return_buf(arc_buf_t *buf, void *tag);
111void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
112void arc_buf_add_ref(arc_buf_t *buf, void *tag);
113boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
114int arc_buf_size(arc_buf_t *buf);
115void arc_release(arc_buf_t *buf, void *tag);
116int arc_released(arc_buf_t *buf);
117void arc_buf_freeze(arc_buf_t *buf);
118void arc_buf_thaw(arc_buf_t *buf);
119boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
120#ifdef ZFS_DEBUG
121int arc_referenced(arc_buf_t *buf);
122#endif
123
124int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
125    arc_done_func_t *done, void *priv, zio_priority_t priority, int flags,
126    arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
127zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
128    blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
129    const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone,
130    arc_done_func_t *done, void *priv, zio_priority_t priority,
131    int zio_flags, const zbookmark_phys_t *zb);
132void arc_freed(spa_t *spa, const blkptr_t *bp);
133
134void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *priv);
135boolean_t arc_clear_callback(arc_buf_t *buf);
136
137void arc_flush(spa_t *spa);
138void arc_tempreserve_clear(uint64_t reserve);
139int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
140
141void arc_init(void);
142void arc_fini(void);
143
144/*
145 * Level 2 ARC
146 */
147
148void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
149void l2arc_remove_vdev(vdev_t *vd);
150boolean_t l2arc_vdev_present(vdev_t *vd);
151void l2arc_init(void);
152void l2arc_fini(void);
153void l2arc_start(void);
154void l2arc_stop(void);
155
156#ifdef illumos
157#ifndef _KERNEL
158extern boolean_t arc_watch;
159extern int arc_procfd;
160#endif
161#endif /* illumos */
162
163#ifdef	__cplusplus
164}
165#endif
166
167#endif /* _SYS_ARC_H */
168