xref: /freebsd/sys/sys/bio.h (revision f05cddf9)
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 
65 #ifdef _KERNEL
66 struct disk;
67 struct bio;
68 struct vm_map;
69 
70 /* Empty classifier tag, to prevent further classification. */
71 #define	BIO_NOTCLASSIFIED		(void *)(~0UL)
72 
73 typedef void bio_task_t(void *);
74 
75 /*
76  * The bio structure describes an I/O operation in the kernel.
77  */
78 struct bio {
79 	uint8_t	bio_cmd;		/* I/O operation. */
80 	uint8_t	bio_flags;		/* General flags. */
81 	uint8_t	bio_cflags;		/* Private use by the consumer. */
82 	uint8_t	bio_pflags;		/* Private use by the provider. */
83 	struct cdev *bio_dev;		/* Device to do I/O on. */
84 	struct disk *bio_disk;		/* Valid below geom_disk.c only */
85 	off_t	bio_offset;		/* Offset into file. */
86 	long	bio_bcount;		/* Valid bytes in buffer. */
87 	caddr_t	bio_data;		/* Memory, superblocks, indirect etc. */
88 	struct vm_page **bio_ma;	/* Or unmapped. */
89 	int	bio_ma_offset;		/* Offset in the first page of bio_ma. */
90 	int	bio_ma_n;		/* Number of pages in bio_ma. */
91 	int	bio_error;		/* Errno for BIO_ERROR. */
92 	long	bio_resid;		/* Remaining I/O in bytes. */
93 	void	(*bio_done)(struct bio *);
94 	void	*bio_driver1;		/* Private use by the provider. */
95 	void	*bio_driver2;		/* Private use by the provider. */
96 	void	*bio_caller1;		/* Private use by the consumer. */
97 	void	*bio_caller2;		/* Private use by the consumer. */
98 	TAILQ_ENTRY(bio) bio_queue;	/* Disksort queue. */
99 	const char *bio_attribute;	/* Attribute for BIO_[GS]ETATTR */
100 	struct g_consumer *bio_from;	/* GEOM linkage */
101 	struct g_provider *bio_to;	/* GEOM linkage */
102 	off_t	bio_length;		/* Like bio_bcount */
103 	off_t	bio_completed;		/* Inverse of bio_resid */
104 	u_int	bio_children;		/* Number of spawned bios */
105 	u_int	bio_inbed;		/* Children safely home by now */
106 	struct bio *bio_parent;		/* Pointer to parent */
107 	struct bintime bio_t0;		/* Time request started */
108 
109 	bio_task_t *bio_task;		/* Task_queue handler */
110 	void	*bio_task_arg;		/* Argument to above */
111 
112 	void	*bio_classifier1;	/* Classifier tag. */
113 	void	*bio_classifier2;	/* Classifier tag. */
114 
115 #ifdef DIAGNOSTIC
116 	void	*_bio_caller1;
117 	void	*_bio_caller2;
118 	uint8_t	_bio_cflags;
119 #endif
120 
121 	/* XXX: these go away when bio chaining is introduced */
122 	daddr_t bio_pblkno;               /* physical block number */
123 };
124 
125 struct uio;
126 struct devstat;
127 
128 struct bio_queue_head {
129 	TAILQ_HEAD(bio_queue, bio) queue;
130 	off_t last_offset;
131 	struct	bio *insert_point;
132 };
133 
134 extern struct vm_map *bio_transient_map;
135 extern int bio_transient_maxcnt;
136 
137 void biodone(struct bio *bp);
138 void biofinish(struct bio *bp, struct devstat *stat, int error);
139 int biowait(struct bio *bp, const char *wchan);
140 
141 void bioq_disksort(struct bio_queue_head *ap, struct bio *bp);
142 struct bio *bioq_first(struct bio_queue_head *head);
143 struct bio *bioq_takefirst(struct bio_queue_head *head);
144 void bioq_flush(struct bio_queue_head *head, struct devstat *stp, int error);
145 void bioq_init(struct bio_queue_head *head);
146 void bioq_insert_head(struct bio_queue_head *head, struct bio *bp);
147 void bioq_insert_tail(struct bio_queue_head *head, struct bio *bp);
148 void bioq_remove(struct bio_queue_head *head, struct bio *bp);
149 
150 void bio_taskqueue(struct bio *bp, bio_task_t *fund, void *arg);
151 
152 int	physio(struct cdev *dev, struct uio *uio, int ioflag);
153 #define physread physio
154 #define physwrite physio
155 
156 #endif /* _KERNEL */
157 
158 #endif /* !_SYS_BIO_H_ */
159