kernel/fs/zfs/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, 2017 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 #define HDR_SET_LSIZE(hdr, x) do { \
  47         ASSERT(IS_P2ALIGNED(x, 1U << SPA_MINBLOCKSHIFT)); \
  48         (hdr)->b_lsize = ((x) >> SPA_MINBLOCKSHIFT); \
  49 _NOTE(CONSTCOND) } while (0)
  50
  51 #define HDR_SET_PSIZE(hdr, x) do { \
  52         ASSERT(IS_P2ALIGNED((x), 1U << SPA_MINBLOCKSHIFT)); \
  53         (hdr)->b_psize = ((x) >> SPA_MINBLOCKSHIFT); \
  54 _NOTE(CONSTCOND) } while (0)
  55
  56 #define HDR_GET_LSIZE(hdr)      ((hdr)->b_lsize << SPA_MINBLOCKSHIFT)
  57 #define HDR_GET_PSIZE(hdr)      ((hdr)->b_psize << SPA_MINBLOCKSHIFT)
  58
  59 typedef struct arc_buf_hdr arc_buf_hdr_t;
  60 typedef struct arc_buf arc_buf_t;
  61 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
  62
  63 /* generic arc_done_func_t's which you can use */
  64 arc_done_func_t arc_bcopy_func;
  65 arc_done_func_t arc_getbuf_func;
  66
  67 typedef enum arc_flags
  68 {
  69         /*
  70          * Public flags that can be passed into the ARC by external consumers.
  71          */
  72         ARC_FLAG_WAIT                   = 1 << 0,       /* perform sync I/O */
  73         ARC_FLAG_NOWAIT                 = 1 << 1,       /* perform async I/O */
  74         ARC_FLAG_PREFETCH               = 1 << 2,       /* I/O is a prefetch */
  75         ARC_FLAG_CACHED                 = 1 << 3,       /* I/O was in cache */
  76         ARC_FLAG_L2CACHE                = 1 << 4,       /* cache in L2ARC */
  77         ARC_FLAG_PREDICTIVE_PREFETCH    = 1 << 5,       /* I/O from zfetch */
  78
  79         /*
  80          * Private ARC flags.  These flags are private ARC only flags that
  81          * will show up in b_flags in the arc_hdr_buf_t. These flags should
  82          * only be set by ARC code.
  83          */
  84         ARC_FLAG_IN_HASH_TABLE          = 1 << 6,       /* buffer is hashed */
  85         ARC_FLAG_IO_IN_PROGRESS         = 1 << 7,       /* I/O in progress */
  86         ARC_FLAG_IO_ERROR               = 1 << 8,       /* I/O failed for buf */
  87         ARC_FLAG_INDIRECT               = 1 << 9,       /* indirect block */
  88         /* Indicates that block was read with ASYNC priority. */
  89         ARC_FLAG_PRIO_ASYNC_READ        = 1 << 10,
  90         ARC_FLAG_L2_WRITING             = 1 << 11,      /* write in progress */
  91         ARC_FLAG_L2_EVICTED             = 1 << 12,      /* evicted during I/O */
  92         ARC_FLAG_L2_WRITE_HEAD          = 1 << 13,      /* head of write list */
  93         /* indicates that the buffer contains metadata (otherwise, data) */
  94         ARC_FLAG_BUFC_METADATA          = 1 << 14,
  95
  96         /* Flags specifying whether optional hdr struct fields are defined */
  97         ARC_FLAG_HAS_L1HDR              = 1 << 15,
  98         ARC_FLAG_HAS_L2HDR              = 1 << 16,
  99
 100         /*
 101          * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
 102          * This allows the l2arc to use the blkptr's checksum to verify
 103          * the data without having to store the checksum in the hdr.
 104          */
 105         ARC_FLAG_COMPRESSED_ARC         = 1 << 17,
 106         ARC_FLAG_SHARED_DATA            = 1 << 18,
 107
 108         /*
 109          * The arc buffer's compression mode is stored in the top 7 bits of the
 110          * flags field, so these dummy flags are included so that MDB can
 111          * interpret the enum properly.
 112          */
 113         ARC_FLAG_COMPRESS_0             = 1 << 24,
 114         ARC_FLAG_COMPRESS_1             = 1 << 25,
 115         ARC_FLAG_COMPRESS_2             = 1 << 26,
 116         ARC_FLAG_COMPRESS_3             = 1 << 27,
 117         ARC_FLAG_COMPRESS_4             = 1 << 28,
 118         ARC_FLAG_COMPRESS_5             = 1 << 29,
 119         ARC_FLAG_COMPRESS_6             = 1 << 30
 120
 121 } arc_flags_t;
 122
 123 typedef enum arc_buf_flags {
 124         ARC_BUF_FLAG_SHARED             = 1 << 0,
 125         ARC_BUF_FLAG_COMPRESSED         = 1 << 1
 126 } arc_buf_flags_t;
 127
 128 struct arc_buf {
 129         arc_buf_hdr_t           *b_hdr;
 130         arc_buf_t               *b_next;
 131         kmutex_t                b_evict_lock;
 132         void                    *b_data;
 133         arc_buf_flags_t         b_flags;
 134 };
 135
 136 typedef enum arc_buf_contents {
 137         ARC_BUFC_INVALID,                       /* invalid type */
 138         ARC_BUFC_DATA,                          /* buffer contains data */
 139         ARC_BUFC_METADATA,                      /* buffer contains metadata */
 140         ARC_BUFC_NUMTYPES
 141 } arc_buf_contents_t;
 142
 143 /*
 144  * The following breakdows of arc_size exist for kstat only.
 145  */
 146 typedef enum arc_space_type {
 147         ARC_SPACE_DATA,
 148         ARC_SPACE_META,
 149         ARC_SPACE_HDRS,
 150         ARC_SPACE_L2HDRS,
 151         ARC_SPACE_OTHER,
 152         ARC_SPACE_NUMTYPES
 153 } arc_space_type_t;
 154
 155 void arc_space_consume(uint64_t space, arc_space_type_t type);
 156 void arc_space_return(uint64_t space, arc_space_type_t type);
 157 boolean_t arc_is_metadata(arc_buf_t *buf);
 158 enum zio_compress arc_get_compression(arc_buf_t *buf);
 159 int arc_decompress(arc_buf_t *buf);
 160 arc_buf_t *arc_alloc_buf(spa_t *spa, void *tag, arc_buf_contents_t type,
 161     int32_t size);
 162 arc_buf_t *arc_alloc_compressed_buf(spa_t *spa, void *tag,
 163     uint64_t psize, uint64_t lsize, enum zio_compress compression_type);
 164 arc_buf_t *arc_loan_buf(spa_t *spa, boolean_t is_metadata, int size);
 165 arc_buf_t *arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize,
 166     enum zio_compress compression_type);
 167 void arc_return_buf(arc_buf_t *buf, void *tag);
 168 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
 169 void arc_buf_destroy(arc_buf_t *buf, void *tag);
 170 int arc_buf_size(arc_buf_t *buf);
 171 int arc_buf_lsize(arc_buf_t *buf);
 172 void arc_release(arc_buf_t *buf, void *tag);
 173 int arc_released(arc_buf_t *buf);
 174 void arc_buf_freeze(arc_buf_t *buf);
 175 void arc_buf_thaw(arc_buf_t *buf);
 176 #ifdef ZFS_DEBUG
 177 int arc_referenced(arc_buf_t *buf);
 178 #endif
 179
 180 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
 181     arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
 182     arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
 183 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
 184     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
 185     arc_done_func_t *ready, arc_done_func_t *child_ready,
 186     arc_done_func_t *physdone, arc_done_func_t *done,
 187     void *private, zio_priority_t priority, int zio_flags,
 188     const zbookmark_phys_t *zb);
 189 void arc_freed(spa_t *spa, const blkptr_t *bp);
 190
 191 void arc_flush(spa_t *spa, boolean_t retry);
 192 void arc_tempreserve_clear(uint64_t reserve);
 193 int arc_tempreserve_space(spa_t *spa, uint64_t reserve, uint64_t txg);
 194
 195 uint64_t arc_max_bytes(void);
 196 void arc_init(void);
 197 void arc_fini(void);
 198
 199 /*
 200  * Level 2 ARC
 201  */
 202
 203 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
 204 void l2arc_remove_vdev(vdev_t *vd);
 205 boolean_t l2arc_vdev_present(vdev_t *vd);
 206 void l2arc_init(void);
 207 void l2arc_fini(void);
 208 void l2arc_start(void);
 209 void l2arc_stop(void);
 210
 211 #ifndef _KERNEL
 212 extern boolean_t arc_watch;
 213 extern int arc_procfd;
 214 #endif
 215
 216 #ifdef  __cplusplus
 217 }
 218 #endif
 219
 220 #endif /* _SYS_ARC_H */