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      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, 2016 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 *priv);
     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 extern int zfs_arc_num_sublists_per_state;
     68 
     69 typedef enum arc_flags
     70 {
     71 	/*
     72 	 * Public flags that can be passed into the ARC by external consumers.
     73 	 */
     74 	ARC_FLAG_WAIT			= 1 << 0,	/* perform sync I/O */
     75 	ARC_FLAG_NOWAIT			= 1 << 1,	/* perform async I/O */
     76 	ARC_FLAG_PREFETCH		= 1 << 2,	/* I/O is a prefetch */
     77 	ARC_FLAG_CACHED			= 1 << 3,	/* I/O was in cache */
     78 	ARC_FLAG_L2CACHE		= 1 << 4,	/* cache in L2ARC */
     79 	ARC_FLAG_PREDICTIVE_PREFETCH	= 1 << 5,	/* I/O from zfetch */
     80 
     81 	/*
     82 	 * Private ARC flags.  These flags are private ARC only flags that
     83 	 * will show up in b_flags in the arc_hdr_buf_t. These flags should
     84 	 * only be set by ARC code.
     85 	 */
     86 	ARC_FLAG_IN_HASH_TABLE		= 1 << 6,	/* buffer is hashed */
     87 	ARC_FLAG_IO_IN_PROGRESS		= 1 << 7,	/* I/O in progress */
     88 	ARC_FLAG_IO_ERROR		= 1 << 8,	/* I/O failed for buf */
     89 	ARC_FLAG_INDIRECT		= 1 << 9,	/* indirect block */
     90 	/* Indicates that block was read with ASYNC priority. */
     91 	ARC_FLAG_PRIO_ASYNC_READ	= 1 << 10,
     92 	ARC_FLAG_L2_WRITING		= 1 << 11,	/* write in progress */
     93 	ARC_FLAG_L2_EVICTED		= 1 << 12,	/* evicted during I/O */
     94 	ARC_FLAG_L2_WRITE_HEAD		= 1 << 13,	/* head of write list */
     95 	/* indicates that the buffer contains metadata (otherwise, data) */
     96 	ARC_FLAG_BUFC_METADATA		= 1 << 14,
     97 
     98 	/* Flags specifying whether optional hdr struct fields are defined */
     99 	ARC_FLAG_HAS_L1HDR		= 1 << 15,
    100 	ARC_FLAG_HAS_L2HDR		= 1 << 16,
    101 
    102 	/*
    103 	 * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
    104 	 * This allows the l2arc to use the blkptr's checksum to verify
    105 	 * the data without having to store the checksum in the hdr.
    106 	 */
    107 	ARC_FLAG_COMPRESSED_ARC		= 1 << 17,
    108 	ARC_FLAG_SHARED_DATA		= 1 << 18,
    109 
    110 	/*
    111 	 * The arc buffer's compression mode is stored in the top 7 bits of the
    112 	 * flags field, so these dummy flags are included so that MDB can
    113 	 * interpret the enum properly.
    114 	 */
    115 	ARC_FLAG_COMPRESS_0		= 1 << 24,
    116 	ARC_FLAG_COMPRESS_1		= 1 << 25,
    117 	ARC_FLAG_COMPRESS_2		= 1 << 26,
    118 	ARC_FLAG_COMPRESS_3		= 1 << 27,
    119 	ARC_FLAG_COMPRESS_4		= 1 << 28,
    120 	ARC_FLAG_COMPRESS_5		= 1 << 29,
    121 	ARC_FLAG_COMPRESS_6		= 1 << 30
    122 
    123 } arc_flags_t;
    124 
    125 struct arc_buf {
    126 	arc_buf_hdr_t		*b_hdr;
    127 	arc_buf_t		*b_next;
    128 	kmutex_t		b_evict_lock;
    129 	void			*b_data;
    130 };
    131 
    132 typedef enum arc_buf_contents {
    133 	ARC_BUFC_INVALID,			/* invalid type */
    134 	ARC_BUFC_DATA,				/* buffer contains data */
    135 	ARC_BUFC_METADATA,			/* buffer contains metadata */
    136 	ARC_BUFC_NUMTYPES
    137 } arc_buf_contents_t;
    138 
    139 /*
    140  * The following breakdows of arc_size exist for kstat only.
    141  */
    142 typedef enum arc_space_type {
    143 	ARC_SPACE_DATA,
    144 	ARC_SPACE_META,
    145 	ARC_SPACE_HDRS,
    146 	ARC_SPACE_L2HDRS,
    147 	ARC_SPACE_OTHER,
    148 	ARC_SPACE_NUMTYPES
    149 } arc_space_type_t;
    150 
    151 void arc_space_consume(uint64_t space, arc_space_type_t type);
    152 void arc_space_return(uint64_t space, arc_space_type_t type);
    153 arc_buf_t *arc_alloc_buf(spa_t *spa, int32_t size, void *tag,
    154     arc_buf_contents_t type);
    155 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
    156 void arc_return_buf(arc_buf_t *buf, void *tag);
    157 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
    158 void arc_buf_destroy(arc_buf_t *buf, void *tag);
    159 int arc_buf_size(arc_buf_t *buf);
    160 void arc_release(arc_buf_t *buf, void *tag);
    161 int arc_released(arc_buf_t *buf);
    162 void arc_buf_freeze(arc_buf_t *buf);
    163 void arc_buf_thaw(arc_buf_t *buf);
    164 #ifdef ZFS_DEBUG
    165 int arc_referenced(arc_buf_t *buf);
    166 #endif
    167 
    168 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
    169     arc_done_func_t *done, void *priv, zio_priority_t priority, int flags,
    170     arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
    171 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
    172     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
    173     arc_done_func_t *ready, arc_done_func_t *child_ready,
    174     arc_done_func_t *physdone, arc_done_func_t *done,
    175     void *priv, zio_priority_t priority, int zio_flags,
    176     const zbookmark_phys_t *zb);
    177 void arc_freed(spa_t *spa, const blkptr_t *bp);
    178 
    179 void arc_flush(spa_t *spa, boolean_t retry);
    180 void arc_tempreserve_clear(uint64_t reserve);
    181 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
    182 
    183 uint64_t arc_max_bytes(void);
    184 void arc_init(void);
    185 void arc_fini(void);
    186 
    187 /*
    188  * Level 2 ARC
    189  */
    190 
    191 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
    192 void l2arc_remove_vdev(vdev_t *vd);
    193 boolean_t l2arc_vdev_present(vdev_t *vd);
    194 void l2arc_init(void);
    195 void l2arc_fini(void);
    196 void l2arc_start(void);
    197 void l2arc_stop(void);
    198 
    199 #ifdef illumos
    200 #ifndef _KERNEL
    201 extern boolean_t arc_watch;
    202 extern int arc_procfd;
    203 #endif
    204 #endif /* illumos */
    205 
    206 #ifdef	__cplusplus
    207 }
    208 #endif
    209 
    210 #endif /* _SYS_ARC_H */
    211