include/sys/arc.h

   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  */
  24
  25 #ifndef _SYS_ARC_H
  26 #define _SYS_ARC_H
  27
  28 #include <sys/zfs_context.h>
  29
  30 #ifdef  __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 #include <sys/zio.h>
  35 #include <sys/dmu.h>
  36 #include <sys/spa.h>
  37 #include <sys/refcount.h>
  38
  39 typedef struct arc_buf_hdr arc_buf_hdr_t;
  40 typedef struct arc_buf arc_buf_t;
  41 typedef struct arc_prune arc_prune_t;
  42 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
  43 typedef void arc_prune_func_t(int64_t bytes, void *private);
  44 typedef int arc_evict_func_t(void *private);
  45
  46 /* generic arc_done_func_t's which you can use */
  47 arc_done_func_t arc_bcopy_func;
  48 arc_done_func_t arc_getbuf_func;
  49
  50 /* generic arc_prune_func_t wrapper for callbacks */
  51 struct arc_prune {
  52         arc_prune_func_t        *p_pfunc;
  53         void                    *p_private;
  54         list_node_t             p_node;
  55         refcount_t              p_refcnt;
  56 };
  57
  58 struct arc_buf {
  59         arc_buf_hdr_t           *b_hdr;
  60         arc_buf_t               *b_next;
  61         kmutex_t                b_evict_lock;
  62         krwlock_t               b_data_lock;
  63         void                    *b_data;
  64         arc_evict_func_t        *b_efunc;
  65         void                    *b_private;
  66 };
  67
  68 typedef enum arc_buf_contents {
  69         ARC_BUFC_DATA,                          /* buffer contains data */
  70         ARC_BUFC_METADATA,                      /* buffer contains metadata */
  71         ARC_BUFC_NUMTYPES
  72 } arc_buf_contents_t;
  73 /*
  74  * These are the flags we pass into calls to the arc
  75  */
  76 #define ARC_WAIT        (1 << 1)        /* perform I/O synchronously */
  77 #define ARC_NOWAIT      (1 << 2)        /* perform I/O asynchronously */
  78 #define ARC_PREFETCH    (1 << 3)        /* I/O is a prefetch */
  79 #define ARC_CACHED      (1 << 4)        /* I/O was already in cache */
  80 #define ARC_L2CACHE     (1 << 5)        /* cache in L2ARC */
  81
  82 /*
  83  * The following breakdows of arc_size exist for kstat only.
  84  */
  85 typedef enum arc_space_type {
  86         ARC_SPACE_DATA,
  87         ARC_SPACE_HDRS,
  88         ARC_SPACE_L2HDRS,
  89         ARC_SPACE_OTHER,
  90         ARC_SPACE_NUMTYPES
  91 } arc_space_type_t;
  92
  93 void arc_space_consume(uint64_t space, arc_space_type_t type);
  94 void arc_space_return(uint64_t space, arc_space_type_t type);
  95 void *arc_data_buf_alloc(uint64_t space);
  96 void arc_data_buf_free(void *buf, uint64_t space);
  97 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
  98     arc_buf_contents_t type);
  99 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
 100 void arc_return_buf(arc_buf_t *buf, void *tag);
 101 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
 102 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
 103 int arc_buf_remove_ref(arc_buf_t *buf, void *tag);
 104 int arc_buf_size(arc_buf_t *buf);
 105 void arc_release(arc_buf_t *buf, void *tag);
 106 int arc_release_bp(arc_buf_t *buf, void *tag, blkptr_t *bp, spa_t *spa,
 107     zbookmark_t *zb);
 108 int arc_released(arc_buf_t *buf);
 109 int arc_has_callback(arc_buf_t *buf);
 110 void arc_buf_freeze(arc_buf_t *buf);
 111 void arc_buf_thaw(arc_buf_t *buf);
 112 boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
 113 #ifdef ZFS_DEBUG
 114 int arc_referenced(arc_buf_t *buf);
 115 #endif
 116
 117 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, arc_buf_t *pbuf,
 118     arc_done_func_t *done, void *private, int priority, int zio_flags,
 119     uint32_t *arc_flags, const zbookmark_t *zb);
 120 int arc_read_nolock(zio_t *pio, spa_t *spa, const blkptr_t *bp,
 121     arc_done_func_t *done, void *private, int priority, int flags,
 122     uint32_t *arc_flags, const zbookmark_t *zb);
 123 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
 124     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
 125     arc_done_func_t *ready, arc_done_func_t *done, void *private,
 126     int priority, int zio_flags, const zbookmark_t *zb);
 127
 128 arc_prune_t *arc_add_prune_callback(arc_prune_func_t *func, void *private);
 129 void arc_remove_prune_callback(arc_prune_t *p);
 130
 131 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
 132 int arc_buf_evict(arc_buf_t *buf);
 133
 134 void arc_adjust_meta(int64_t adjustment, boolean_t may_prune);
 135 void arc_flush(spa_t *spa);
 136 void arc_tempreserve_clear(uint64_t reserve);
 137 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
 138
 139 void arc_init(void);
 140 void arc_fini(void);
 141
 142 /*
 143  * Level 2 ARC
 144  */
 145
 146 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
 147 void l2arc_remove_vdev(vdev_t *vd);
 148 boolean_t l2arc_vdev_present(vdev_t *vd);
 149 void l2arc_init(void);
 150 void l2arc_fini(void);
 151 void l2arc_start(void);
 152 void l2arc_stop(void);
 153
 154 /* Global tunings */
 155 extern int zfs_write_limit_shift;
 156 extern unsigned long zfs_write_limit_max;
 157 extern kmutex_t zfs_write_limit_lock;
 158
 159 #ifdef  __cplusplus
 160 }
 161 #endif
 162
 163 #endif /* _SYS_ARC_H */