module/zfs/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 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_ARC_H
  27 #define _SYS_ARC_H
  28
  29 #include <sys/zfs_context.h>
  30
  31 #ifdef  __cplusplus
  32 extern "C" {
  33 #endif
  34
  35 #include <sys/zio.h>
  36 #include <sys/dmu.h>
  37 #include <sys/spa.h>
  38
  39 typedef struct arc_buf_hdr arc_buf_hdr_t;
  40 typedef struct arc_buf arc_buf_t;
  41 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
  42 typedef int arc_evict_func_t(void *private);
  43
  44 /* generic arc_done_func_t's which you can use */
  45 arc_done_func_t arc_bcopy_func;
  46 arc_done_func_t arc_getbuf_func;
  47
  48 struct arc_buf {
  49         arc_buf_hdr_t           *b_hdr;
  50         arc_buf_t               *b_next;
  51         krwlock_t               b_lock;
  52         void                    *b_data;
  53         arc_evict_func_t        *b_efunc;
  54         void                    *b_private;
  55 };
  56
  57 typedef enum arc_buf_contents {
  58         ARC_BUFC_DATA,                          /* buffer contains data */
  59         ARC_BUFC_METADATA,                      /* buffer contains metadata */
  60         ARC_BUFC_NUMTYPES
  61 } arc_buf_contents_t;
  62 /*
  63  * These are the flags we pass into calls to the arc
  64  */
  65 #define ARC_WAIT        (1 << 1)        /* perform I/O synchronously */
  66 #define ARC_NOWAIT      (1 << 2)        /* perform I/O asynchronously */
  67 #define ARC_PREFETCH    (1 << 3)        /* I/O is a prefetch */
  68 #define ARC_CACHED      (1 << 4)        /* I/O was already in cache */
  69 #define ARC_L2CACHE     (1 << 5)        /* cache in L2ARC */
  70
  71 /*
  72  * The following breakdows of arc_size exist for kstat only.
  73  */
  74 typedef enum arc_space_type {
  75         ARC_SPACE_DATA,
  76         ARC_SPACE_HDRS,
  77         ARC_SPACE_L2HDRS,
  78         ARC_SPACE_OTHER,
  79         ARC_SPACE_NUMTYPES
  80 } arc_space_type_t;
  81
  82 void arc_space_consume(uint64_t space, arc_space_type_t type);
  83 void arc_space_return(uint64_t space, arc_space_type_t type);
  84 void *arc_data_buf_alloc(uint64_t space);
  85 void arc_data_buf_free(void *buf, uint64_t space);
  86 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
  87     arc_buf_contents_t type);
  88 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
  89 void arc_return_buf(arc_buf_t *buf, void *tag);
  90 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
  91 int arc_buf_remove_ref(arc_buf_t *buf, void *tag);
  92 int arc_buf_size(arc_buf_t *buf);
  93 void arc_release(arc_buf_t *buf, void *tag);
  94 int arc_released(arc_buf_t *buf);
  95 int arc_has_callback(arc_buf_t *buf);
  96 void arc_buf_freeze(arc_buf_t *buf);
  97 void arc_buf_thaw(arc_buf_t *buf);
  98 #ifdef ZFS_DEBUG
  99 int arc_referenced(arc_buf_t *buf);
 100 #endif
 101
 102 typedef struct writeprops {
 103         dmu_object_type_t wp_type;
 104         uint8_t wp_level;
 105         uint8_t wp_copies;
 106         uint8_t wp_dncompress, wp_oscompress;
 107         uint8_t wp_dnchecksum, wp_oschecksum;
 108 } writeprops_t;
 109
 110 void write_policy(spa_t *spa, const writeprops_t *wp, zio_prop_t *zp);
 111 int arc_read(zio_t *pio, spa_t *spa, blkptr_t *bp, arc_buf_t *pbuf,
 112     arc_done_func_t *done, void *private, int priority, int zio_flags,
 113     uint32_t *arc_flags, const zbookmark_t *zb);
 114 int arc_read_nolock(zio_t *pio, spa_t *spa, blkptr_t *bp,
 115     arc_done_func_t *done, void *private, int priority, int flags,
 116     uint32_t *arc_flags, const zbookmark_t *zb);
 117 zio_t *arc_write(zio_t *pio, spa_t *spa, const writeprops_t *wp,
 118     boolean_t l2arc, uint64_t txg, blkptr_t *bp, arc_buf_t *buf,
 119     arc_done_func_t *ready, arc_done_func_t *done, void *private, int priority,
 120     int zio_flags, const zbookmark_t *zb);
 121 int arc_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 122     zio_done_func_t *done, void *private, uint32_t arc_flags);
 123 int arc_tryread(spa_t *spa, blkptr_t *bp, void *data);
 124
 125 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
 126 int arc_buf_evict(arc_buf_t *buf);
 127
 128 void arc_flush(spa_t *spa);
 129 void arc_tempreserve_clear(uint64_t reserve);
 130 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
 131
 132 void arc_init(void);
 133 void arc_fini(void);
 134
 135 /*
 136  * Level 2 ARC
 137  */
 138
 139 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
 140 void l2arc_remove_vdev(vdev_t *vd);
 141 boolean_t l2arc_vdev_present(vdev_t *vd);
 142 void l2arc_init(void);
 143 void l2arc_fini(void);
 144 void l2arc_start(void);
 145 void l2arc_stop(void);
 146
 147 #ifdef  __cplusplus
 148 }
 149 #endif
 150
 151 #endif /* _SYS_ARC_H */