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) 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
  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 /*
  42  * Used by arc_flush() to inform arc_evict_state() that it should evict
  43  * all available buffers from the arc state being passed in.
  44  */
  45 #define ARC_EVICT_ALL   -1ULL
  46
  47 typedef struct arc_buf_hdr arc_buf_hdr_t;
  48 typedef struct arc_buf arc_buf_t;
  49 typedef struct arc_prune arc_prune_t;
  50 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
  51 typedef void arc_prune_func_t(int64_t bytes, void *private);
  52 typedef int arc_evict_func_t(void *private);
  53
  54 /* Shared module parameters */
  55 extern int zfs_arc_average_blocksize;
  56
  57 /* generic arc_done_func_t's which you can use */
  58 arc_done_func_t arc_bcopy_func;
  59 arc_done_func_t arc_getbuf_func;
  60
  61 /* generic arc_prune_func_t wrapper for callbacks */
  62 struct arc_prune {
  63         arc_prune_func_t        *p_pfunc;
  64         void                    *p_private;
  65         uint64_t                p_adjust;
  66         list_node_t             p_node;
  67         refcount_t              p_refcnt;
  68 };
  69
  70 typedef enum arc_strategy {
  71         ARC_STRATEGY_META_ONLY          = 0, /* Evict only meta data buffers */
  72         ARC_STRATEGY_META_BALANCED      = 1, /* Evict data buffers if needed */
  73 } arc_strategy_t;
  74
  75 typedef enum arc_flags
  76 {
  77         /*
  78          * Public flags that can be passed into the ARC by external consumers.
  79          */
  80         ARC_FLAG_NONE                   = 1 << 0,       /* No flags set */
  81         ARC_FLAG_WAIT                   = 1 << 1,       /* perform sync I/O */
  82         ARC_FLAG_NOWAIT                 = 1 << 2,       /* perform async I/O */
  83         ARC_FLAG_PREFETCH               = 1 << 3,       /* I/O is a prefetch */
  84         ARC_FLAG_CACHED                 = 1 << 4,       /* I/O was in cache */
  85         ARC_FLAG_L2CACHE                = 1 << 5,       /* cache in L2ARC */
  86         ARC_FLAG_L2COMPRESS             = 1 << 6,       /* compress in L2ARC */
  87
  88         /*
  89          * Private ARC flags.  These flags are private ARC only flags that
  90          * will show up in b_flags in the arc_hdr_buf_t. These flags should
  91          * only be set by ARC code.
  92          */
  93         ARC_FLAG_IN_HASH_TABLE          = 1 << 7,       /* buffer is hashed */
  94         ARC_FLAG_IO_IN_PROGRESS         = 1 << 8,       /* I/O in progress */
  95         ARC_FLAG_IO_ERROR               = 1 << 9,       /* I/O failed for buf */
  96         ARC_FLAG_FREED_IN_READ          = 1 << 10,      /* freed during read */
  97         ARC_FLAG_BUF_AVAILABLE          = 1 << 11,      /* block not in use */
  98         ARC_FLAG_INDIRECT               = 1 << 12,      /* indirect block */
  99         ARC_FLAG_L2_WRITING             = 1 << 13,      /* write in progress */
 100         ARC_FLAG_L2_EVICTED             = 1 << 14,      /* evicted during I/O */
 101         ARC_FLAG_L2_WRITE_HEAD          = 1 << 15,      /* head of write list */
 102         /* indicates that the buffer contains metadata (otherwise, data) */
 103         ARC_FLAG_BUFC_METADATA          = 1 << 16,
 104
 105         /* Flags specifying whether optional hdr struct fields are defined */
 106         ARC_FLAG_HAS_L1HDR              = 1 << 17,
 107         ARC_FLAG_HAS_L2HDR              = 1 << 18,
 108 } arc_flags_t;
 109
 110 struct arc_buf {
 111         arc_buf_hdr_t           *b_hdr;
 112         arc_buf_t               *b_next;
 113         kmutex_t                b_evict_lock;
 114         void                    *b_data;
 115         arc_evict_func_t        *b_efunc;
 116         void                    *b_private;
 117 };
 118
 119 typedef enum arc_buf_contents {
 120         ARC_BUFC_DATA,                          /* buffer contains data */
 121         ARC_BUFC_METADATA,                      /* buffer contains metadata */
 122         ARC_BUFC_NUMTYPES
 123 } arc_buf_contents_t;
 124
 125 /*
 126  * The following breakdows of arc_size exist for kstat only.
 127  */
 128 typedef enum arc_space_type {
 129         ARC_SPACE_DATA,
 130         ARC_SPACE_META,
 131         ARC_SPACE_HDRS,
 132         ARC_SPACE_L2HDRS,
 133         ARC_SPACE_OTHER,
 134         ARC_SPACE_NUMTYPES
 135 } arc_space_type_t;
 136
 137 typedef enum arc_state_type {
 138         ARC_STATE_ANON,
 139         ARC_STATE_MRU,
 140         ARC_STATE_MRU_GHOST,
 141         ARC_STATE_MFU,
 142         ARC_STATE_MFU_GHOST,
 143         ARC_STATE_L2C_ONLY,
 144         ARC_STATE_NUMTYPES
 145 } arc_state_type_t;
 146
 147 typedef struct arc_buf_info {
 148         arc_state_type_t        abi_state_type;
 149         arc_buf_contents_t      abi_state_contents;
 150         uint32_t                abi_flags;
 151         uint32_t                abi_datacnt;
 152         uint64_t                abi_size;
 153         uint64_t                abi_spa;
 154         uint64_t                abi_access;
 155         uint32_t                abi_mru_hits;
 156         uint32_t                abi_mru_ghost_hits;
 157         uint32_t                abi_mfu_hits;
 158         uint32_t                abi_mfu_ghost_hits;
 159         uint32_t                abi_l2arc_hits;
 160         uint32_t                abi_holds;
 161         uint64_t                abi_l2arc_dattr;
 162         uint64_t                abi_l2arc_asize;
 163         enum zio_compress       abi_l2arc_compress;
 164 } arc_buf_info_t;
 165
 166 void arc_space_consume(uint64_t space, arc_space_type_t type);
 167 void arc_space_return(uint64_t space, arc_space_type_t type);
 168 arc_buf_t *arc_buf_alloc(spa_t *spa, uint64_t size, void *tag,
 169     arc_buf_contents_t type);
 170 arc_buf_t *arc_loan_buf(spa_t *spa, uint64_t size);
 171 void arc_return_buf(arc_buf_t *buf, void *tag);
 172 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
 173 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
 174 boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
 175 void arc_buf_info(arc_buf_t *buf, arc_buf_info_t *abi, int state_index);
 176 uint64_t arc_buf_size(arc_buf_t *buf);
 177 void arc_release(arc_buf_t *buf, void *tag);
 178 int arc_released(arc_buf_t *buf);
 179 void arc_buf_sigsegv(int sig, siginfo_t *si, void *unused);
 180 void arc_buf_freeze(arc_buf_t *buf);
 181 void arc_buf_thaw(arc_buf_t *buf);
 182 boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
 183 #ifdef ZFS_DEBUG
 184 int arc_referenced(arc_buf_t *buf);
 185 #endif
 186
 187 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
 188     arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
 189     arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
 190 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
 191     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
 192     const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone,
 193     arc_done_func_t *done, void *private, zio_priority_t priority,
 194     int zio_flags, const zbookmark_phys_t *zb);
 195
 196 arc_prune_t *arc_add_prune_callback(arc_prune_func_t *func, void *private);
 197 void arc_remove_prune_callback(arc_prune_t *p);
 198 void arc_freed(spa_t *spa, const blkptr_t *bp);
 199
 200 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
 201 boolean_t arc_clear_callback(arc_buf_t *buf);
 202
 203 void arc_flush(spa_t *spa, boolean_t retry);
 204 void arc_tempreserve_clear(uint64_t reserve);
 205 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
 206
 207 void arc_init(void);
 208 void arc_fini(void);
 209
 210 /*
 211  * Level 2 ARC
 212  */
 213
 214 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
 215 void l2arc_remove_vdev(vdev_t *vd);
 216 boolean_t l2arc_vdev_present(vdev_t *vd);
 217 void l2arc_init(void);
 218 void l2arc_fini(void);
 219 void l2arc_start(void);
 220 void l2arc_stop(void);
 221
 222 #ifndef _KERNEL
 223 extern boolean_t arc_watch;
 224 #endif
 225
 226 #ifdef  __cplusplus
 227 }
 228 #endif
 229
 230 #endif /* _SYS_ARC_H */