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 
  40 /*
  41  * Used by arc_flush() to inform arc_evict_state() that it should evict
  42  * all available buffers from the arc state being passed in.
  43  */
  44 #define ARC_EVICT_ALL   -1ULL
  45 
  46 typedef struct arc_buf_hdr arc_buf_hdr_t;
  47 typedef struct arc_buf arc_buf_t;
  48 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
  49 typedef int arc_evict_func_t(void *private);
  50 
  51 /* generic arc_done_func_t's which you can use */
  52 arc_done_func_t arc_bcopy_func;
  53 arc_done_func_t arc_getbuf_func;
  54 
  55 typedef enum arc_flags
  56 {
  57         /*
  58          * Public flags that can be passed into the ARC by external consumers.
  59          */
  60         ARC_FLAG_NONE                   = 1 << 0, /* No flags set */
  61         ARC_FLAG_WAIT                   = 1 << 1, /* perform sync I/O */
  62         ARC_FLAG_NOWAIT                 = 1 << 2, /* perform async I/O */
  63         ARC_FLAG_PREFETCH               = 1 << 3, /* I/O is a prefetch */
  64         ARC_FLAG_CACHED                 = 1 << 4, /* I/O was in cache */
  65         ARC_FLAG_L2CACHE                = 1 << 5, /* cache in L2ARC */
  66         ARC_FLAG_L2COMPRESS             = 1 << 6, /* compress in L2ARC */
  67 
  68         /*
  69          * Private ARC flags.  These flags are private ARC only flags that
  70          * will show up in b_flags in the arc_hdr_buf_t. These flags should
  71          * only be set by ARC code.
  72          */
  73         ARC_FLAG_IN_HASH_TABLE          = 1 << 7, /* buffer is hashed */
  74         ARC_FLAG_IO_IN_PROGRESS         = 1 << 8, /* I/O in progress */
  75         ARC_FLAG_IO_ERROR               = 1 << 9, /* I/O failed for buf */
  76         ARC_FLAG_FREED_IN_READ          = 1 << 10,        /* freed during read */
  77         ARC_FLAG_BUF_AVAILABLE          = 1 << 11,        /* block not in use */
  78         ARC_FLAG_INDIRECT               = 1 << 12,        /* indirect block */
  79         ARC_FLAG_L2_WRITING             = 1 << 13,        /* write in progress */
  80         ARC_FLAG_L2_EVICTED             = 1 << 14,        /* evicted during I/O */
  81         ARC_FLAG_L2_WRITE_HEAD          = 1 << 15,        /* head of write list */
  82         /* indicates that the buffer contains metadata (otherwise, data) */
  83         ARC_FLAG_BUFC_METADATA          = 1 << 16,
  84 
  85         /* Flags specifying whether optional hdr struct fields are defined */
  86         ARC_FLAG_HAS_L1HDR              = 1 << 17,
  87         ARC_FLAG_HAS_L2HDR              = 1 << 18,
  88 } arc_flags_t;
  89 
  90 struct arc_buf {
  91         arc_buf_hdr_t           *b_hdr;
  92         arc_buf_t               *b_next;
  93         kmutex_t                b_evict_lock;
  94         void                    *b_data;
  95         arc_evict_func_t        *b_efunc;
  96         void                    *b_private;
  97 };
  98 
  99 typedef enum arc_buf_contents {
 100         ARC_BUFC_DATA,                          /* buffer contains data */
 101         ARC_BUFC_METADATA,                      /* buffer contains metadata */
 102         ARC_BUFC_NUMTYPES
 103 } arc_buf_contents_t;
 104 
 105 /*
 106  * The following breakdows of arc_size exist for kstat only.
 107  */
 108 typedef enum arc_space_type {
 109         ARC_SPACE_DATA,
 110         ARC_SPACE_META,
 111         ARC_SPACE_HDRS,
 112         ARC_SPACE_L2HDRS,
 113         ARC_SPACE_OTHER,
 114         ARC_SPACE_NUMTYPES
 115 } arc_space_type_t;
 116 
 117 void arc_space_consume(uint64_t space, arc_space_type_t type);
 118 void arc_space_return(uint64_t space, arc_space_type_t type);
 119 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
 120     arc_buf_contents_t type);
 121 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
 122 void arc_return_buf(arc_buf_t *buf, void *tag);
 123 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
 124 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
 125 boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
 126 int arc_buf_size(arc_buf_t *buf);
 127 void arc_release(arc_buf_t *buf, void *tag);
 128 int arc_released(arc_buf_t *buf);
 129 void arc_buf_freeze(arc_buf_t *buf);
 130 void arc_buf_thaw(arc_buf_t *buf);
 131 boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
 132 #ifdef ZFS_DEBUG
 133 int arc_referenced(arc_buf_t *buf);
 134 #endif
 135 
 136 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
 137     arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
 138     arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
 139 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
 140     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
 141     const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone,
 142     arc_done_func_t *done, void *private, zio_priority_t priority,
 143     int zio_flags, const zbookmark_phys_t *zb);
 144 void arc_freed(spa_t *spa, const blkptr_t *bp);
 145 
 146 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
 147 boolean_t arc_clear_callback(arc_buf_t *buf);
 148 
 149 void arc_flush(spa_t *spa, boolean_t retry);
 150 void arc_tempreserve_clear(uint64_t reserve);
 151 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
 152 
 153 void arc_init(void);
 154 void arc_fini(void);
 155 
 156 /*
 157  * Level 2 ARC
 158  */
 159 
 160 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
 161 void l2arc_remove_vdev(vdev_t *vd);
 162 boolean_t l2arc_vdev_present(vdev_t *vd);
 163 void l2arc_init(void);
 164 void l2arc_fini(void);
 165 void l2arc_start(void);
 166 void l2arc_stop(void);
 167 
 168 #ifndef _KERNEL
 169 extern boolean_t arc_watch;
 170 extern int arc_procfd;
 171 #endif
 172 
 173 #ifdef  __cplusplus
 174 }
 175 #endif
 176 
 177 #endif /* _SYS_ARC_H */