[mirror_ubuntu-zesty-kernel.git] / zfs / include / sys / arc.h

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
 */

#ifndef	_SYS_ARC_H
#define	_SYS_ARC_H

#include <sys/zfs_context.h>

#ifdef	__cplusplus
extern "C" {
#endif

#include <sys/zio.h>
#include <sys/dmu.h>
#include <sys/spa.h>
#include <sys/refcount.h>

/*
 * Used by arc_flush() to inform arc_evict_state() that it should evict
 * all available buffers from the arc state being passed in.
 */
#define	ARC_EVICT_ALL	-1ULL

typedef struct arc_buf_hdr arc_buf_hdr_t;
typedef struct arc_buf arc_buf_t;
typedef struct arc_prune arc_prune_t;
typedef void arc_done_func_t(zio_t *zio, arc_buf_t *buf, void *private);
typedef void arc_prune_func_t(int64_t bytes, void *private);
typedef int arc_evict_func_t(void *private);

/* Shared module parameters */
extern int zfs_arc_average_blocksize;

/* generic arc_done_func_t's which you can use */
arc_done_func_t arc_bcopy_func;
arc_done_func_t arc_getbuf_func;

/* generic arc_prune_func_t wrapper for callbacks */
struct arc_prune {
	arc_prune_func_t	*p_pfunc;
	void			*p_private;
	uint64_t		p_adjust;
	list_node_t		p_node;
	refcount_t		p_refcnt;
};

typedef enum arc_strategy {
	ARC_STRATEGY_META_ONLY		= 0, /* Evict only meta data buffers */
	ARC_STRATEGY_META_BALANCED	= 1, /* Evict data buffers if needed */
} arc_strategy_t;

typedef enum arc_flags
{
	/*
	 * Public flags that can be passed into the ARC by external consumers.
	 */
	ARC_FLAG_NONE			= 1 << 0,	/* No flags set */
	ARC_FLAG_WAIT			= 1 << 1,	/* perform sync I/O */
	ARC_FLAG_NOWAIT			= 1 << 2,	/* perform async I/O */
	ARC_FLAG_PREFETCH		= 1 << 3,	/* I/O is a prefetch */
	ARC_FLAG_CACHED			= 1 << 4,	/* I/O was in cache */
	ARC_FLAG_L2CACHE		= 1 << 5,	/* cache in L2ARC */
	ARC_FLAG_L2COMPRESS		= 1 << 6,	/* compress in L2ARC */

	/*
	 * Private ARC flags.  These flags are private ARC only flags that
	 * will show up in b_flags in the arc_hdr_buf_t. These flags should
	 * only be set by ARC code.
	 */
	ARC_FLAG_IN_HASH_TABLE		= 1 << 7,	/* buffer is hashed */
	ARC_FLAG_IO_IN_PROGRESS		= 1 << 8,	/* I/O in progress */
	ARC_FLAG_IO_ERROR		= 1 << 9,	/* I/O failed for buf */
	ARC_FLAG_FREED_IN_READ		= 1 << 10,	/* freed during read */
	ARC_FLAG_BUF_AVAILABLE		= 1 << 11,	/* block not in use */
	ARC_FLAG_INDIRECT		= 1 << 12,	/* indirect block */
	ARC_FLAG_L2_WRITING		= 1 << 13,	/* write in progress */
	ARC_FLAG_L2_EVICTED		= 1 << 14,	/* evicted during I/O */
	ARC_FLAG_L2_WRITE_HEAD		= 1 << 15,	/* head of write list */
	/* indicates that the buffer contains metadata (otherwise, data) */
	ARC_FLAG_BUFC_METADATA		= 1 << 16,

	/* Flags specifying whether optional hdr struct fields are defined */
	ARC_FLAG_HAS_L1HDR		= 1 << 17,
	ARC_FLAG_HAS_L2HDR		= 1 << 18,
} arc_flags_t;

struct arc_buf {
	arc_buf_hdr_t		*b_hdr;
	arc_buf_t		*b_next;
	kmutex_t		b_evict_lock;
	void			*b_data;
	arc_evict_func_t	*b_efunc;
	void			*b_private;
};

typedef enum arc_buf_contents {
	ARC_BUFC_DATA,				/* buffer contains data */
	ARC_BUFC_METADATA,			/* buffer contains metadata */
	ARC_BUFC_NUMTYPES
} arc_buf_contents_t;

/*
 * The following breakdows of arc_size exist for kstat only.
 */
typedef enum arc_space_type {
	ARC_SPACE_DATA,
	ARC_SPACE_META,
	ARC_SPACE_HDRS,
	ARC_SPACE_L2HDRS,
	ARC_SPACE_OTHER,
	ARC_SPACE_NUMTYPES
} arc_space_type_t;

typedef enum arc_state_type {
	ARC_STATE_ANON,
	ARC_STATE_MRU,
	ARC_STATE_MRU_GHOST,
	ARC_STATE_MFU,
	ARC_STATE_MFU_GHOST,
	ARC_STATE_L2C_ONLY,
	ARC_STATE_NUMTYPES
} arc_state_type_t;

typedef struct arc_buf_info {
	arc_state_type_t	abi_state_type;
	arc_buf_contents_t	abi_state_contents;
	uint32_t		abi_flags;
	uint32_t		abi_datacnt;
	uint64_t		abi_size;
	uint64_t		abi_spa;
	uint64_t		abi_access;
	uint32_t		abi_mru_hits;
	uint32_t		abi_mru_ghost_hits;
	uint32_t		abi_mfu_hits;
	uint32_t		abi_mfu_ghost_hits;
	uint32_t		abi_l2arc_hits;
	uint32_t		abi_holds;
	uint64_t		abi_l2arc_dattr;
	uint64_t		abi_l2arc_asize;
	enum zio_compress	abi_l2arc_compress;
} arc_buf_info_t;

void arc_space_consume(uint64_t space, arc_space_type_t type);
void arc_space_return(uint64_t space, arc_space_type_t type);
arc_buf_t *arc_buf_alloc(spa_t *spa, uint64_t size, void *tag,
    arc_buf_contents_t type);
arc_buf_t *arc_loan_buf(spa_t *spa, uint64_t size);
void arc_return_buf(arc_buf_t *buf, void *tag);
void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
void arc_buf_add_ref(arc_buf_t *buf, void *tag);
boolean_t arc_buf_remove_ref(arc_buf_t *buf, void *tag);
void arc_buf_info(arc_buf_t *buf, arc_buf_info_t *abi, int state_index);
uint64_t arc_buf_size(arc_buf_t *buf);
void arc_release(arc_buf_t *buf, void *tag);
int arc_released(arc_buf_t *buf);
void arc_buf_sigsegv(int sig, siginfo_t *si, void *unused);
void arc_buf_freeze(arc_buf_t *buf);
void arc_buf_thaw(arc_buf_t *buf);
boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
#ifdef ZFS_DEBUG
int arc_referenced(arc_buf_t *buf);
#endif

int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
    arc_done_func_t *done, void *private, zio_priority_t priority, int flags,
    arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
    blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress,
    const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *physdone,
    arc_done_func_t *done, void *private, zio_priority_t priority,
    int zio_flags, const zbookmark_phys_t *zb);

arc_prune_t *arc_add_prune_callback(arc_prune_func_t *func, void *private);
void arc_remove_prune_callback(arc_prune_t *p);
void arc_freed(spa_t *spa, const blkptr_t *bp);

void arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private);
boolean_t arc_clear_callback(arc_buf_t *buf);

void arc_flush(spa_t *spa, boolean_t retry);
void arc_tempreserve_clear(uint64_t reserve);
int arc_tempreserve_space(uint64_t reserve, uint64_t txg);

void arc_init(void);
void arc_fini(void);

/*
 * Level 2 ARC
 */

void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
void l2arc_remove_vdev(vdev_t *vd);
boolean_t l2arc_vdev_present(vdev_t *vd);
void l2arc_init(void);
void l2arc_fini(void);
void l2arc_start(void);
void l2arc_stop(void);

#ifndef _KERNEL
extern boolean_t arc_watch;
#endif

#ifdef	__cplusplus
}
#endif

#endif /* _SYS_ARC_H */
Commit	Line	Data
7bdf406d TG	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.
0bd31011	23	* Copyright (c) 2012, 2014 by Delphix. All rights reserved.
7bdf406d TG	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	#include <sys/refcount.h>
	40
	41	/*
	42	* Used by arc_flush() to inform arc_evict_state() that it should evict
	43	* all available buffers from the arc state being passed in.
	44	*/
	45	#define ARC_EVICT_ALL -1ULL
	46
	47	typedef struct arc_buf_hdr arc_buf_hdr_t;
	48	typedef struct arc_buf arc_buf_t;
	49	typedef struct arc_prune arc_prune_t;
	50	typedef void arc_done_func_t(zio_t zio, arc_buf_t buf, void *private);
	51	typedef void arc_prune_func_t(int64_t bytes, void *private);
0bd31011	52	typedef int arc_evict_func_t(void *private);
7bdf406d TG	53
	54	/* Shared module parameters */
	55	extern int zfs_arc_average_blocksize;
	56
	57	/* generic arc_done_func_t's which you can use */
	58	arc_done_func_t arc_bcopy_func;
	59	arc_done_func_t arc_getbuf_func;
	60
	61	/* generic arc_prune_func_t wrapper for callbacks */
	62	struct arc_prune {
	63	arc_prune_func_t *p_pfunc;
	64	void *p_private;
	65	uint64_t p_adjust;
	66	list_node_t p_node;
	67	refcount_t p_refcnt;
	68	};
	69
	70	typedef enum arc_strategy {
	71	ARC_STRATEGY_META_ONLY = 0, /* Evict only meta data buffers */
	72	ARC_STRATEGY_META_BALANCED = 1, /* Evict data buffers if needed */
	73	} arc_strategy_t;
	74
	75	typedef enum arc_flags
	76	{
	77	/*
	78	* Public flags that can be passed into the ARC by external consumers.
	79	*/
0bd31011 TG	80	ARC_FLAG_NONE = 1 << 0, /* No flags set */
	81	ARC_FLAG_WAIT = 1 << 1, /* perform sync I/O */
	82	ARC_FLAG_NOWAIT = 1 << 2, /* perform async I/O */
	83	ARC_FLAG_PREFETCH = 1 << 3, /* I/O is a prefetch */
	84	ARC_FLAG_CACHED = 1 << 4, /* I/O was in cache */
	85	ARC_FLAG_L2CACHE = 1 << 5, /* cache in L2ARC */
	86	ARC_FLAG_L2COMPRESS = 1 << 6, /* compress in L2ARC */
7bdf406d TG	87
	88	/*
	89	* Private ARC flags. These flags are private ARC only flags that
	90	* will show up in b_flags in the arc_hdr_buf_t. These flags should
	91	* only be set by ARC code.
	92	*/
0bd31011 TG	93	ARC_FLAG_IN_HASH_TABLE = 1 << 7, /* buffer is hashed */
	94	ARC_FLAG_IO_IN_PROGRESS = 1 << 8, /* I/O in progress */
	95	ARC_FLAG_IO_ERROR = 1 << 9, /* I/O failed for buf */
	96	ARC_FLAG_FREED_IN_READ = 1 << 10, /* freed during read */
	97	ARC_FLAG_BUF_AVAILABLE = 1 << 11, /* block not in use */
	98	ARC_FLAG_INDIRECT = 1 << 12, /* indirect block */
	99	ARC_FLAG_L2_WRITING = 1 << 13, /* write in progress */
	100	ARC_FLAG_L2_EVICTED = 1 << 14, /* evicted during I/O */
	101	ARC_FLAG_L2_WRITE_HEAD = 1 << 15, /* head of write list */
7bdf406d	102	/* indicates that the buffer contains metadata (otherwise, data) */
0bd31011	103	ARC_FLAG_BUFC_METADATA = 1 << 16,
7bdf406d TG	104
7bdf406d TG	105	/* Flags specifying whether optional hdr struct fields are defined */
0bd31011 TG	106	ARC_FLAG_HAS_L1HDR = 1 << 17,
0bd31011 TG	107	ARC_FLAG_HAS_L2HDR = 1 << 18,
7bdf406d TG	108	} arc_flags_t;
	109
	110	struct arc_buf {
	111	arc_buf_hdr_t *b_hdr;
	112	arc_buf_t *b_next;
	113	kmutex_t b_evict_lock;
	114	void *b_data;
0bd31011 TG	115	arc_evict_func_t *b_efunc;
0bd31011 TG	116	void *b_private;
7bdf406d TG	117	};
	118
	119	typedef enum arc_buf_contents {
	120	ARC_BUFC_DATA, /* buffer contains data */
	121	ARC_BUFC_METADATA, /* buffer contains metadata */
	122	ARC_BUFC_NUMTYPES
	123	} arc_buf_contents_t;
	124
	125	/*
	126	* The following breakdows of arc_size exist for kstat only.
	127	*/
	128	typedef enum arc_space_type {
	129	ARC_SPACE_DATA,
	130	ARC_SPACE_META,
	131	ARC_SPACE_HDRS,
	132	ARC_SPACE_L2HDRS,
0bd31011	133	ARC_SPACE_OTHER,
7bdf406d TG	134	ARC_SPACE_NUMTYPES
	135	} arc_space_type_t;
	136
	137	typedef enum arc_state_type {
	138	ARC_STATE_ANON,
	139	ARC_STATE_MRU,
	140	ARC_STATE_MRU_GHOST,
	141	ARC_STATE_MFU,
	142	ARC_STATE_MFU_GHOST,
	143	ARC_STATE_L2C_ONLY,
	144	ARC_STATE_NUMTYPES
	145	} arc_state_type_t;
	146
	147	typedef struct arc_buf_info {
	148	arc_state_type_t abi_state_type;
	149	arc_buf_contents_t abi_state_contents;
	150	uint32_t abi_flags;
0bd31011	151	uint32_t abi_datacnt;
7bdf406d TG	152	uint64_t abi_size;
	153	uint64_t abi_spa;
	154	uint64_t abi_access;
	155	uint32_t abi_mru_hits;
	156	uint32_t abi_mru_ghost_hits;
	157	uint32_t abi_mfu_hits;
	158	uint32_t abi_mfu_ghost_hits;
	159	uint32_t abi_l2arc_hits;
	160	uint32_t abi_holds;
	161	uint64_t abi_l2arc_dattr;
	162	uint64_t abi_l2arc_asize;
	163	enum zio_compress abi_l2arc_compress;
	164	} arc_buf_info_t;
	165
	166	void arc_space_consume(uint64_t space, arc_space_type_t type);
	167	void arc_space_return(uint64_t space, arc_space_type_t type);
0bd31011 TG	168	arc_buf_t arc_buf_alloc(spa_t spa, uint64_t size, void *tag,
	169	arc_buf_contents_t type);
	170	arc_buf_t arc_loan_buf(spa_t spa, uint64_t size);
7bdf406d TG	171	void arc_return_buf(arc_buf_t buf, void tag);
7bdf406d TG	172	void arc_loan_inuse_buf(arc_buf_t buf, void tag);
0bd31011 TG	173	void arc_buf_add_ref(arc_buf_t buf, void tag);
0bd31011 TG	174	boolean_t arc_buf_remove_ref(arc_buf_t buf, void tag);
7bdf406d TG	175	void arc_buf_info(arc_buf_t buf, arc_buf_info_t abi, int state_index);
	176	uint64_t arc_buf_size(arc_buf_t *buf);
	177	void arc_release(arc_buf_t buf, void tag);
	178	int arc_released(arc_buf_t *buf);
	179	void arc_buf_sigsegv(int sig, siginfo_t si, void unused);
	180	void arc_buf_freeze(arc_buf_t *buf);
	181	void arc_buf_thaw(arc_buf_t *buf);
0bd31011	182	boolean_t arc_buf_eviction_needed(arc_buf_t *buf);
7bdf406d TG	183	#ifdef ZFS_DEBUG
	184	int arc_referenced(arc_buf_t *buf);
	185	#endif
	186
	187	int arc_read(zio_t pio, spa_t spa, const blkptr_t *bp,
	188	arc_done_func_t done, void private, zio_priority_t priority, int flags,
	189	arc_flags_t arc_flags, const zbookmark_phys_t zb);
	190	zio_t arc_write(zio_t pio, spa_t *spa, uint64_t txg,
0bd31011 TG	191	blkptr_t bp, arc_buf_t buf, boolean_t l2arc, boolean_t l2arc_compress,
	192	const zio_prop_t zp, arc_done_func_t ready, arc_done_func_t *physdone,
	193	arc_done_func_t done, void private, zio_priority_t priority,
	194	int zio_flags, const zbookmark_phys_t *zb);
7bdf406d TG	195
	196	arc_prune_t arc_add_prune_callback(arc_prune_func_t func, void *private);
	197	void arc_remove_prune_callback(arc_prune_t *p);
	198	void arc_freed(spa_t spa, const blkptr_t bp);
	199
0bd31011 TG	200	void arc_set_callback(arc_buf_t buf, arc_evict_func_t func, void *private);
	201	boolean_t arc_clear_callback(arc_buf_t *buf);
	202
7bdf406d TG	203	void arc_flush(spa_t *spa, boolean_t retry);
	204	void arc_tempreserve_clear(uint64_t reserve);
	205	int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
	206
	207	void arc_init(void);
	208	void arc_fini(void);
	209
	210	/*
	211	* Level 2 ARC
	212	*/
	213
	214	void l2arc_add_vdev(spa_t spa, vdev_t vd);
	215	void l2arc_remove_vdev(vdev_t *vd);
	216	boolean_t l2arc_vdev_present(vdev_t *vd);
	217	void l2arc_init(void);
	218	void l2arc_fini(void);
	219	void l2arc_start(void);
	220	void l2arc_stop(void);
	221
	222	#ifndef _KERNEL
	223	extern boolean_t arc_watch;
	224	#endif
	225
	226	#ifdef __cplusplus
	227	}
	228	#endif
	229
	230	#endif /* _SYS_ARC_H */