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 typedef struct arc_buf_hdr arc_buf_hdr_t; 41 typedef struct arc_buf arc_buf_t; 42 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private); 43 typedef int arc_evict_func_t(void *private); 44 45 /* generic arc_done_func_t's which you can use */ 46 arc_done_func_t arc_bcopy_func; 47 arc_done_func_t arc_getbuf_func; 48 49 typedef enum arc_flags 50 { 51 /* 52 * Public flags that can be passed into the ARC by external consumers. 53 */ 54 ARC_FLAG_NONE = 1 << 0, /* No flags set */ 55 ARC_FLAG_WAIT = 1 << 1, /* perform sync I/O */ 56 ARC_FLAG_NOWAIT = 1 << 2, /* perform async I/O */ 57 ARC_FLAG_PREFETCH = 1 << 3, /* I/O is a prefetch */ 58 ARC_FLAG_CACHED = 1 << 4, /* I/O was in cache */ 59 ARC_FLAG_L2CACHE = 1 << 5, /* cache in L2ARC */ 60 ARC_FLAG_L2COMPRESS = 1 << 6, /* compress in L2ARC */ 61 62 /* 63 * Private ARC flags. These flags are private ARC only flags that 64 * will show up in b_flags in the arc_hdr_buf_t. These flags should 65 * only be set by ARC code. 66 */ 67 ARC_FLAG_IN_HASH_TABLE = 1 << 7, /* buffer is hashed */ 68 ARC_FLAG_IO_IN_PROGRESS = 1 << 8, /* I/O in progress */ 69 ARC_FLAG_IO_ERROR = 1 << 9, /* I/O failed for buf */ 70 ARC_FLAG_FREED_IN_READ = 1 << 10, /* freed during read */ 71 ARC_FLAG_BUF_AVAILABLE = 1 << 11, /* block not in use */ 72 ARC_FLAG_INDIRECT = 1 << 12, /* indirect block */ 73 ARC_FLAG_L2_WRITING = 1 << 13, /* write in progress */ 74 ARC_FLAG_L2_EVICTED = 1 << 14, /* evicted during I/O */ 75 ARC_FLAG_L2_WRITE_HEAD = 1 << 15, /* head of write list */ 76 /* indicates that the buffer contains metadata (otherwise, data) */ 77 ARC_FLAG_BUFC_METADATA = 1 << 16, 78 79 /* Flags specifying whether optional hdr struct fields are defined */ 80 ARC_FLAG_HAS_L1HDR = 1 << 17, 81 ARC_FLAG_HAS_L2HDR = 1 << 18, 82 83 /* 84 * The arc buffer's compression mode is stored in the top 7 bits of the 85 * flags field, so these dummy flags are included so that MDB can 86 * interpret the enum properly. 87 */ 88 ARC_FLAG_COMPRESS_0 = 1 << 24, 89 ARC_FLAG_COMPRESS_1 = 1 << 25, 90 ARC_FLAG_COMPRESS_2 = 1 << 26, 91 ARC_FLAG_COMPRESS_3 = 1 << 27, 92 ARC_FLAG_COMPRESS_4 = 1 << 28, 93 ARC_FLAG_COMPRESS_5 = 1 << 29, 94 ARC_FLAG_COMPRESS_6 = 1 << 30 95 96 } arc_flags_t; 97 98 struct arc_buf { 99 arc_buf_hdr_t *b_hdr; 100 arc_buf_t *b_next; 101 kmutex_t b_evict_lock; 102 void *b_data; 103 arc_evict_func_t *b_efunc; 104 void *b_private; 105 }; 106 107 typedef enum arc_buf_contents { 108 ARC_BUFC_DATA, /* buffer contains data */ 109 ARC_BUFC_METADATA, /* buffer contains metadata */ 110 ARC_BUFC_NUMTYPES 111 } arc_buf_contents_t; 112 113 /* 114 * The following breakdows of arc_size exist for kstat only. 115 */ 116 typedef enum arc_space_type { 117 ARC_SPACE_DATA, 118 ARC_SPACE_HDRS, 119 ARC_SPACE_L2HDRS, 120 ARC_SPACE_OTHER, 121 ARC_SPACE_NUMTYPES 122 } arc_space_type_t; 123 124 void arc_space_consume(uint64_t space, arc_space_type_t type); 125 void arc_space_return(uint64_t space, arc_space_type_t type); 126 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag, 127 arc_buf_contents_t type); 128 arc_buf_t *arc_loan_buf(spa_t *spa, int size); 129 void arc_return_buf(arc_buf_t *buf, void *tag); 130 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag); 131 void arc_buf_add_ref(arc_buf_t *buf, void *tag); 132 boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag); 133 int arc_buf_size(arc_buf_t *buf); 134 void arc_release(arc_buf_t *buf, void *tag); 135 int arc_released(arc_buf_t *buf); 136 void arc_buf_freeze(arc_buf_t *buf); 137 void arc_buf_thaw(arc_buf_t *buf); 138 boolean_t arc_buf_eviction_needed(arc_buf_t *buf); 139 #ifdef ZFS_DEBUG 140 int arc_referenced(arc_buf_t *buf); 141 #endif 142 143 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 144 arc_done_func_t *done, void *private, zio_priority_t priority, int flags, 145 arc_flags_t *arc_flags, const zbookmark_phys_t *zb); 146 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg, 147 blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress, 148 const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone, 149 arc_done_func_t *done, void *private, zio_priority_t priority, 150 int zio_flags, const zbookmark_phys_t *zb); 151 void arc_freed(spa_t *spa, const blkptr_t *bp); 152 153 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private); 154 boolean_t arc_clear_callback(arc_buf_t *buf); 155 156 void arc_flush(spa_t *spa); 157 void arc_tempreserve_clear(uint64_t reserve); 158 int arc_tempreserve_space(uint64_t reserve, uint64_t txg); 159 160 void arc_init(void); 161 void arc_fini(void); 162 163 /* 164 * Level 2 ARC 165 */ 166 167 void l2arc_add_vdev(spa_t *spa, vdev_t *vd); 168 void l2arc_remove_vdev(vdev_t *vd); 169 boolean_t l2arc_vdev_present(vdev_t *vd); 170 void l2arc_init(void); 171 void l2arc_fini(void); 172 void l2arc_start(void); 173 void l2arc_stop(void); 174 175 #ifndef _KERNEL 176 extern boolean_t arc_watch; 177 extern int arc_procfd; 178 #endif 179 180 #ifdef __cplusplus 181 } 182 #endif 183 184 #endif /* _SYS_ARC_H */ 185