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  * Copyright (c) 2013 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
  33 extern "C" {
  34 #endif
  35
  36 #include <sys/zio.h>
  37 #include <sys/dmu.h>
  38 #include <sys/spa.h>
  39 #include <sys/refcount.h>
  40
  41 typedef struct arc_buf_hdr arc_buf_hdr_t;
  42 typedef struct arc_buf arc_buf_t;
  43 typedef struct arc_prune arc_prune_t;
  44 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
  45 typedef void arc_prune_func_t(int64_t bytes, void *private);
  46 typedef int arc_evict_func_t(void *private);
  47
  48 /* generic arc_done_func_t's which you can use */
  49 arc_done_func_t arc_bcopy_func;
  50 arc_done_func_t arc_getbuf_func;
  51
  52 /* generic arc_prune_func_t wrapper for callbacks */
  53 struct arc_prune {
  54         arc_prune_func_t        *p_pfunc;
  55         void                    *p_private;
  56         list_node_t             p_node;
  57         refcount_t              p_refcnt;
  58 };
  59
  60 struct arc_buf {
  61         arc_buf_hdr_t           *b_hdr;
  62         arc_buf_t               *b_next;
  63         kmutex_t                b_evict_lock;
  64         void                    *b_data;
  65         arc_evict_func_t        *b_efunc;
  66         void                    *b_private;
  67 };
  68
  69 typedef enum arc_buf_contents {
  70         ARC_BUFC_DATA,                          /* buffer contains data */
  71         ARC_BUFC_METADATA,                      /* buffer contains metadata */
  72         ARC_BUFC_NUMTYPES
  73 } arc_buf_contents_t;
  74 /*
  75  * These are the flags we pass into calls to the arc
  76  */
  77 #define ARC_WAIT        (1 << 1)        /* perform I/O synchronously */
  78 #define ARC_NOWAIT      (1 << 2)        /* perform I/O asynchronously */
  79 #define ARC_PREFETCH    (1 << 3)        /* I/O is a prefetch */
  80 #define ARC_CACHED      (1 << 4)        /* I/O was already in cache */
  81 #define ARC_L2CACHE     (1 << 5)        /* cache in L2ARC */
  82 #define ARC_L2COMPRESS  (1 << 6)        /* compress in L2ARC */
  83
  84 /*
  85  * The following breakdows of arc_size exist for kstat only.
  86  */
  87 typedef enum arc_space_type {
  88         ARC_SPACE_DATA,
  89         ARC_SPACE_HDRS,
  90         ARC_SPACE_L2HDRS,
  91         ARC_SPACE_OTHER,
  92         ARC_SPACE_NUMTYPES
  93 } arc_space_type_t;
  94
  95 typedef enum arc_state_type {
  96         ARC_STATE_ANON,
  97         ARC_STATE_MRU,
  98         ARC_STATE_MRU_GHOST,
  99         ARC_STATE_MFU,
 100         ARC_STATE_MFU_GHOST,
 101         ARC_STATE_L2C_ONLY,
 102         ARC_STATE_NUMTYPES
 103 } arc_state_type_t;
 104
 105 typedef struct arc_buf_info {
 106         arc_state_type_t        abi_state_type;
 107         arc_buf_contents_t      abi_state_contents;
 108         uint64_t                abi_state_index;
 109         uint32_t                abi_flags;
 110         uint32_t                abi_datacnt;
 111         uint64_t                abi_size;
 112         uint64_t                abi_spa;
 113         uint64_t                abi_access;
 114         uint32_t                abi_mru_hits;
 115         uint32_t                abi_mru_ghost_hits;
 116         uint32_t                abi_mfu_hits;
 117         uint32_t                abi_mfu_ghost_hits;
 118         uint32_t                abi_l2arc_hits;
 119         uint32_t                abi_holds;
 120         uint64_t                abi_l2arc_dattr;
 121         uint64_t                abi_l2arc_asize;
 122         enum zio_compress       abi_l2arc_compress;
 123 } arc_buf_info_t;
 124
 125 void arc_space_consume(uint64_t space, arc_space_type_t type);
 126 void arc_space_return(uint64_t space, arc_space_type_t type);
 127 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
 128     arc_buf_contents_t type);
 129 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
 130 void arc_return_buf(arc_buf_t *buf, void *tag);
 131 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
 132 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
 133 boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
 134 void arc_buf_info(arc_buf_t *buf, arc_buf_info_t *abi, int state_index);
 135 int arc_buf_size(arc_buf_t *buf);
 136 void arc_release(arc_buf_t *buf, void *tag);
 137 int arc_released(arc_buf_t *buf);
 138 int arc_has_callback(arc_buf_t *buf);
 139 void arc_buf_sigsegv(int sig, siginfo_t *si, void *unused);
 140 void arc_buf_freeze(arc_buf_t *buf);
 141 void arc_buf_thaw(arc_buf_t *buf);
 142 boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
 143 #ifdef ZFS_DEBUG
 144 int arc_referenced(arc_buf_t *buf);
 145 #endif
 146
 147 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
 148     arc_done_func_t *done, void *private, int priority, int flags,
 149     uint32_t *arc_flags, const zbookmark_t *zb);
 150 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
 151     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
 152     const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *done,
 153     void *private, int priority, int zio_flags, const zbookmark_t *zb);
 154
 155 arc_prune_t *arc_add_prune_callback(arc_prune_func_t *func, void *private);
 156 void arc_remove_prune_callback(arc_prune_t *p);
 157 void arc_freed(spa_t *spa, const blkptr_t *bp);
 158
 159 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
 160 int arc_buf_evict(arc_buf_t *buf);
 161
 162 void arc_adjust_meta(int64_t adjustment, boolean_t may_prune);
 163 void arc_flush(spa_t *spa);
 164 void arc_tempreserve_clear(uint64_t reserve);
 165 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
 166
 167 void arc_init(void);
 168 void arc_fini(void);
 169
 170 /*
 171  * Level 2 ARC
 172  */
 173
 174 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
 175 void l2arc_remove_vdev(vdev_t *vd);
 176 boolean_t l2arc_vdev_present(vdev_t *vd);
 177 void l2arc_init(void);
 178 void l2arc_fini(void);
 179 void l2arc_start(void);
 180 void l2arc_stop(void);
 181
 182 /* Global tunings */
 183 extern int zfs_write_limit_shift;
 184 extern unsigned long zfs_write_limit_max;
 185 extern kmutex_t zfs_write_limit_lock;
 186
 187 #ifndef _KERNEL
 188 extern boolean_t arc_watch;
 189 #endif
 190
 191 #ifdef  __cplusplus
 192 }
 193 #endif
 194
 195 #endif /* _SYS_ARC_H */