xref: /NextBSD/sys/sys/bio.h (revision 4557fabb34e865d7f40be64b39c9e34fa41dbb60)
1 /*-
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)buf.h	8.9 (Berkeley) 3/30/95
35  * $FreeBSD$
36  */
37 
38 #ifndef _SYS_BIO_H_
39 #define	_SYS_BIO_H_
40 
41 #include <sys/queue.h>
42 
43 /* bio_cmd */
44 #define BIO_READ	0x01	/* Read I/O data */
45 #define BIO_WRITE	0x02	/* Write I/O data */
46 #define BIO_DELETE	0x04	/* TRIM or free blocks, i.e. mark as unused */
47 #define BIO_GETATTR	0x08	/* Get GEOM attributes of object */
48 #define BIO_FLUSH	0x10	/* Commit outstanding I/O now */
49 #define BIO_CMD0	0x20	/* Available for local hacks */
50 #define BIO_CMD1	0x40	/* Available for local hacks */
51 #define BIO_CMD2	0x80	/* Available for local hacks */
52 
53 /* bio_flags */
54 #define BIO_ERROR	0x01	/* An error occurred processing this bio. */
55 #define BIO_DONE	0x02	/* This bio is finished. */
56 #define BIO_ONQUEUE	0x04	/* This bio is in a queue & not yet taken. */
57 /*
58  * This bio must be executed after all previous bios in the queue have been
59  * executed, and before any successive bios can be executed.
60  */
61 #define BIO_ORDERED	0x08
62 #define	BIO_UNMAPPED	0x10
63 #define	BIO_TRANSIENT_MAPPING	0x20
64 #define	BIO_VLIST	0x40
65 
66 #ifdef _KERNEL
67 struct disk;
68 struct bio;
69 struct vm_map;
70 
71 /* Empty classifier tag, to prevent further classification. */
72 #define	BIO_NOTCLASSIFIED		(void *)(~0UL)
73 
74 typedef void bio_task_t(void *);
75 
76 /*
77  * The bio structure describes an I/O operation in the kernel.
78  */
79 struct bio {
80 	uint8_t	bio_cmd;		/* I/O operation. */
81 	uint8_t	bio_flags;		/* General flags. */
82 	uint8_t	bio_cflags;		/* Private use by the consumer. */
83 	uint8_t	bio_pflags;		/* Private use by the provider. */
84 	struct cdev *bio_dev;		/* Device to do I/O on. */
85 	struct disk *bio_disk;		/* Valid below geom_disk.c only */
86 	off_t	bio_offset;		/* Offset into file. */
87 	long	bio_bcount;		/* Valid bytes in buffer. */
88 	caddr_t	bio_data;		/* Memory, superblocks, indirect etc. */
89 	struct vm_page **bio_ma;	/* Or unmapped. */
90 	int	bio_ma_offset;		/* Offset in the first page of bio_ma. */
91 	int	bio_ma_n;		/* Number of pages in bio_ma. */
92 	int	bio_error;		/* Errno for BIO_ERROR. */
93 	long	bio_resid;		/* Remaining I/O in bytes. */
94 	void	(*bio_done)(struct bio *);
95 	void	*bio_driver1;		/* Private use by the provider. */
96 	void	*bio_driver2;		/* Private use by the provider. */
97 	void	*bio_caller1;		/* Private use by the consumer. */
98 	void	*bio_caller2;		/* Private use by the consumer. */
99 	TAILQ_ENTRY(bio) bio_queue;	/* Disksort queue. */
100 	const char *bio_attribute;	/* Attribute for BIO_[GS]ETATTR */
101 	struct g_consumer *bio_from;	/* GEOM linkage */
102 	struct g_provider *bio_to;	/* GEOM linkage */
103 	off_t	bio_length;		/* Like bio_bcount */
104 	off_t	bio_completed;		/* Inverse of bio_resid */
105 	u_int	bio_children;		/* Number of spawned bios */
106 	u_int	bio_inbed;		/* Children safely home by now */
107 	struct bio *bio_parent;		/* Pointer to parent */
108 	struct bintime bio_t0;		/* Time request started */
109 
110 	bio_task_t *bio_task;		/* Task_queue handler */
111 	void	*bio_task_arg;		/* Argument to above */
112 
113 	void	*bio_classifier1;	/* Classifier tag. */
114 	void	*bio_classifier2;	/* Classifier tag. */
115 
116 #ifdef DIAGNOSTIC
117 	void	*_bio_caller1;
118 	void	*_bio_caller2;
119 	uint8_t	_bio_cflags;
120 #endif
121 
122 	/* XXX: these go away when bio chaining is introduced */
123 	daddr_t bio_pblkno;               /* physical block number */
124 };
125 
126 struct uio;
127 struct devstat;
128 
129 struct bio_queue_head {
130 	TAILQ_HEAD(bio_queue, bio) queue;
131 	off_t last_offset;
132 	struct	bio *insert_point;
133 };
134 
135 extern struct vm_map *bio_transient_map;
136 extern int bio_transient_maxcnt;
137 
138 void biodone(struct bio *bp);
139 void biofinish(struct bio *bp, struct devstat *stat, int error);
140 int biowait(struct bio *bp, const char *wchan);
141 
142 void bioq_disksort(struct bio_queue_head *ap, struct bio *bp);
143 struct bio *bioq_first(struct bio_queue_head *head);
144 struct bio *bioq_takefirst(struct bio_queue_head *head);
145 void bioq_flush(struct bio_queue_head *head, struct devstat *stp, int error);
146 void bioq_init(struct bio_queue_head *head);
147 void bioq_insert_head(struct bio_queue_head *head, struct bio *bp);
148 void bioq_insert_tail(struct bio_queue_head *head, struct bio *bp);
149 void bioq_remove(struct bio_queue_head *head, struct bio *bp);
150 
151 void bio_taskqueue(struct bio *bp, bio_task_t *fund, void *arg);
152 
153 int	physio(struct cdev *dev, struct uio *uio, int ioflag);
154 #define physread physio
155 #define physwrite physio
156 
157 #endif /* _KERNEL */
158 
159 #endif /* !_SYS_BIO_H_ */
160