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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 2009 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #ifndef	_SYS_ARC_H
     27 #define	_SYS_ARC_H
     28 
     29 #include <sys/zfs_context.h>
     30 
     31 #ifdef	__cplusplus
     32 extern "C" {
     33 #endif
     34 
     35 #include <sys/zio.h>
     36 #include <sys/dmu.h>
     37 #include <sys/spa.h>
     38 
     39 typedef struct arc_buf_hdr arc_buf_hdr_t;
     40 typedef struct arc_buf arc_buf_t;
     41 typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
     42 typedef int arc_evict_func_t(void *private);
     43 
     44 /* generic arc_done_func_t's which you can use */
     45 arc_done_func_t arc_bcopy_func;
     46 arc_done_func_t arc_getbuf_func;
     47 
     48 struct arc_buf {
     49 	arc_buf_hdr_t		*b_hdr;
     50 	arc_buf_t		*b_next;
     51 	krwlock_t		b_lock;
     52 	void			*b_data;
     53 	arc_evict_func_t	*b_efunc;
     54 	void			*b_private;
     55 };
     56 
     57 typedef enum arc_buf_contents {
     58 	ARC_BUFC_DATA,				/* buffer contains data */
     59 	ARC_BUFC_METADATA,			/* buffer contains metadata */
     60 	ARC_BUFC_NUMTYPES
     61 } arc_buf_contents_t;
     62 /*
     63  * These are the flags we pass into calls to the arc
     64  */
     65 #define	ARC_WAIT	(1 << 1)	/* perform I/O synchronously */
     66 #define	ARC_NOWAIT	(1 << 2)	/* perform I/O asynchronously */
     67 #define	ARC_PREFETCH	(1 << 3)	/* I/O is a prefetch */
     68 #define	ARC_CACHED	(1 << 4)	/* I/O was already in cache */
     69 #define	ARC_L2CACHE	(1 << 5)	/* cache in L2ARC */
     70 
     71 /*
     72  * The following breakdows of arc_size exist for kstat only.
     73  */
     74 typedef enum arc_space_type {
     75 	ARC_SPACE_DATA,
     76 	ARC_SPACE_HDRS,
     77 	ARC_SPACE_L2HDRS,
     78 	ARC_SPACE_OTHER,
     79 	ARC_SPACE_NUMTYPES
     80 } arc_space_type_t;
     81 
     82 void arc_space_consume(uint64_t space, arc_space_type_t type);
     83 void arc_space_return(uint64_t space, arc_space_type_t type);
     84 void *arc_data_buf_alloc(uint64_t space);
     85 void arc_data_buf_free(void *buf, uint64_t space);
     86 arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
     87     arc_buf_contents_t type);
     88 arc_buf_t *arc_loan_buf(spa_t *spa, int size);
     89 void arc_return_buf(arc_buf_t *buf, void *tag);
     90 void arc_buf_add_ref(arc_buf_t *buf, void *tag);
     91 int arc_buf_remove_ref(arc_buf_t *buf, void *tag);
     92 int arc_buf_size(arc_buf_t *buf);
     93 void arc_release(arc_buf_t *buf, void *tag);
     94 int arc_released(arc_buf_t *buf);
     95 int arc_has_callback(arc_buf_t *buf);
     96 void arc_buf_freeze(arc_buf_t *buf);
     97 void arc_buf_thaw(arc_buf_t *buf);
     98 #ifdef ZFS_DEBUG
     99 int arc_referenced(arc_buf_t *buf);
    100 #endif
    101 
    102 int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, arc_buf_t *pbuf,
    103     arc_done_func_t *done, void *private, int priority, int zio_flags,
    104     uint32_t *arc_flags, const zbookmark_t *zb);
    105 int arc_read_nolock(zio_t *pio, spa_t *spa, const blkptr_t *bp,
    106     arc_done_func_t *done, void *private, int priority, int flags,
    107     uint32_t *arc_flags, const zbookmark_t *zb);
    108 zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
    109     blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
    110     arc_done_func_t *ready, arc_done_func_t *done, void *private,
    111     int priority, int zio_flags, const zbookmark_t *zb);
    112 void arc_free(spa_t *spa, const blkptr_t *bp);
    113 
    114 void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
    115 int arc_buf_evict(arc_buf_t *buf);
    116 
    117 void arc_flush(spa_t *spa);
    118 void arc_tempreserve_clear(uint64_t reserve);
    119 int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
    120 
    121 void arc_init(void);
    122 void arc_fini(void);
    123 
    124 /*
    125  * Level 2 ARC
    126  */
    127 
    128 void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
    129 void l2arc_remove_vdev(vdev_t *vd);
    130 boolean_t l2arc_vdev_present(vdev_t *vd);
    131 void l2arc_init(void);
    132 void l2arc_fini(void);
    133 void l2arc_start(void);
    134 void l2arc_stop(void);
    135 
    136 #ifdef	__cplusplus
    137 }
    138 #endif
    139 
    140 #endif /* _SYS_ARC_H */
    141