xref: /freebsd/sys/contrib/openzfs/include/sys/dmu_zfetch.h (revision 5469a9953005a9a4d4aad7be88545d441622e9a0)
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 /*
27  * Copyright (c) 2014, 2017 by Delphix. All rights reserved.
28  */
29 
30 #ifndef	_DMU_ZFETCH_H
31 #define	_DMU_ZFETCH_H
32 
33 #include <sys/zfs_context.h>
34 
35 #ifdef	__cplusplus
36 extern "C" {
37 #endif
38 
39 extern unsigned long	zfetch_array_rd_sz;
40 
41 struct dnode;				/* so we can reference dnode */
42 
43 typedef struct zfetch {
44 	kmutex_t	zf_lock;	/* protects zfetch structure */
45 	list_t		zf_stream;	/* list of zstream_t's */
46 	struct dnode	*zf_dnode;	/* dnode that owns this zfetch */
47 	int		zf_numstreams;	/* number of zstream_t's */
48 } zfetch_t;
49 
50 typedef struct zstream {
51 	uint64_t	zs_blkid;	/* expect next access at this blkid */
52 	uint64_t	zs_pf_blkid1;	/* first block to prefetch */
53 	uint64_t	zs_pf_blkid;	/* block to prefetch up to */
54 
55 	/*
56 	 * We will next prefetch the L1 indirect block of this level-0
57 	 * block id.
58 	 */
59 	uint64_t	zs_ipf_blkid1;	/* first block to prefetch */
60 	uint64_t	zs_ipf_blkid;	/* block to prefetch up to */
61 
62 	list_node_t	zs_node;	/* link for zf_stream */
63 	hrtime_t	zs_atime;	/* time last prefetch issued */
64 	zfetch_t	*zs_fetch;	/* parent fetch */
65 	boolean_t	zs_missed;	/* stream saw cache misses */
66 	zfs_refcount_t	zs_callers;	/* number of pending callers */
67 	/*
68 	 * Number of stream references: dnode, callers and pending blocks.
69 	 * The stream memory is freed when the number returns to zero.
70 	 */
71 	zfs_refcount_t	zs_refs;
72 } zstream_t;
73 
74 void		zfetch_init(void);
75 void		zfetch_fini(void);
76 
77 void		dmu_zfetch_init(zfetch_t *, struct dnode *);
78 void		dmu_zfetch_fini(zfetch_t *);
79 zstream_t	*dmu_zfetch_prepare(zfetch_t *, uint64_t, uint64_t, boolean_t,
80     boolean_t);
81 void		dmu_zfetch_run(zstream_t *, boolean_t, boolean_t);
82 void		dmu_zfetch(zfetch_t *, uint64_t, uint64_t, boolean_t, boolean_t,
83     boolean_t);
84 
85 
86 #ifdef	__cplusplus
87 }
88 #endif
89 
90 #endif	/* _DMU_ZFETCH_H */
91