xref: /freebsd/sys/sys/bio.h (revision 4f52dfbb)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)buf.h	8.9 (Berkeley) 3/30/95
37  * $FreeBSD$
38  */
39 
40 #ifndef _SYS_BIO_H_
41 #define	_SYS_BIO_H_
42 
43 #include <sys/queue.h>
44 #include <sys/disk_zone.h>
45 
46 /* bio_cmd */
47 #define BIO_READ	0x01	/* Read I/O data */
48 #define BIO_WRITE	0x02	/* Write I/O data */
49 #define BIO_DELETE	0x03	/* TRIM or free blocks, i.e. mark as unused */
50 #define BIO_GETATTR	0x04	/* Get GEOM attributes of object */
51 #define BIO_FLUSH	0x05	/* Commit outstanding I/O now */
52 #define BIO_CMD0	0x06	/* Available for local hacks */
53 #define BIO_CMD1	0x07	/* Available for local hacks */
54 #define BIO_CMD2	0x08	/* Available for local hacks */
55 #define BIO_ZONE	0x09	/* Zone command */
56 
57 /* bio_flags */
58 #define BIO_ERROR	0x01	/* An error occurred processing this bio. */
59 #define BIO_DONE	0x02	/* This bio is finished. */
60 #define BIO_ONQUEUE	0x04	/* This bio is in a queue & not yet taken. */
61 /*
62  * This bio must be executed after all previous bios in the queue have been
63  * executed, and before any successive bios can be executed.
64  */
65 #define BIO_ORDERED	0x08
66 #define	BIO_UNMAPPED	0x10
67 #define	BIO_TRANSIENT_MAPPING	0x20
68 #define	BIO_VLIST	0x40
69 
70 #ifdef _KERNEL
71 struct disk;
72 struct bio;
73 struct vm_map;
74 
75 /* Empty classifier tag, to prevent further classification. */
76 #define	BIO_NOTCLASSIFIED		(void *)(~0UL)
77 
78 typedef void bio_task_t(void *);
79 
80 /*
81  * The bio structure describes an I/O operation in the kernel.
82  */
83 struct bio {
84 	uint16_t bio_cmd;		/* I/O operation. */
85 	uint16_t bio_flags;		/* General flags. */
86 	uint16_t bio_cflags;		/* Private use by the consumer. */
87 	uint16_t bio_pflags;		/* Private use by the provider. */
88 	struct cdev *bio_dev;		/* Device to do I/O on. */
89 	struct disk *bio_disk;		/* Valid below geom_disk.c only */
90 	off_t	bio_offset;		/* Offset into file. */
91 	long	bio_bcount;		/* Valid bytes in buffer. */
92 	caddr_t	bio_data;		/* Memory, superblocks, indirect etc. */
93 	struct vm_page **bio_ma;	/* Or unmapped. */
94 	int	bio_ma_offset;		/* Offset in the first page of bio_ma. */
95 	int	bio_ma_n;		/* Number of pages in bio_ma. */
96 	int	bio_error;		/* Errno for BIO_ERROR. */
97 	long	bio_resid;		/* Remaining I/O in bytes. */
98 	void	(*bio_done)(struct bio *);
99 	void	*bio_driver1;		/* Private use by the provider. */
100 	void	*bio_driver2;		/* Private use by the provider. */
101 	void	*bio_caller1;		/* Private use by the consumer. */
102 	void	*bio_caller2;		/* Private use by the consumer. */
103 	TAILQ_ENTRY(bio) bio_queue;	/* Disksort queue. */
104 	const char *bio_attribute;	/* Attribute for BIO_[GS]ETATTR */
105 	struct  disk_zone_args bio_zone;/* Used for BIO_ZONE */
106 	struct g_consumer *bio_from;	/* GEOM linkage */
107 	struct g_provider *bio_to;	/* GEOM linkage */
108 	off_t	bio_length;		/* Like bio_bcount */
109 	off_t	bio_completed;		/* Inverse of bio_resid */
110 	u_int	bio_children;		/* Number of spawned bios */
111 	u_int	bio_inbed;		/* Children safely home by now */
112 	struct bio *bio_parent;		/* Pointer to parent */
113 	struct bintime bio_t0;		/* Time request started */
114 
115 	bio_task_t *bio_task;		/* Task_queue handler */
116 	void	*bio_task_arg;		/* Argument to above */
117 
118 	void	*bio_classifier1;	/* Classifier tag. */
119 	void	*bio_classifier2;	/* Classifier tag. */
120 
121 #ifdef DIAGNOSTIC
122 	void	*_bio_caller1;
123 	void	*_bio_caller2;
124 	uint8_t	_bio_cflags;
125 #endif
126 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
127 	struct buf *bio_track_bp;	/* Parent buf for tracking */
128 #endif
129 
130 	/* XXX: these go away when bio chaining is introduced */
131 	daddr_t bio_pblkno;               /* physical block number */
132 };
133 
134 struct uio;
135 struct devstat;
136 
137 struct bio_queue_head {
138 	TAILQ_HEAD(bio_queue, bio) queue;
139 	off_t last_offset;
140 	struct	bio *insert_point;
141 };
142 
143 extern struct vm_map *bio_transient_map;
144 extern int bio_transient_maxcnt;
145 
146 void biodone(struct bio *bp);
147 void biofinish(struct bio *bp, struct devstat *stat, int error);
148 int biowait(struct bio *bp, const char *wchan);
149 
150 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
151 void biotrack_buf(struct bio *bp, const char *location);
152 
153 static __inline void
154 biotrack(struct bio *bp, const char *location)
155 {
156 
157 	if (bp->bio_track_bp != NULL)
158 		biotrack_buf(bp, location);
159 }
160 #else
161 static __inline void
162 biotrack(struct bio *bp __unused, const char *location __unused)
163 {
164 }
165 #endif
166 
167 void bioq_disksort(struct bio_queue_head *ap, struct bio *bp);
168 struct bio *bioq_first(struct bio_queue_head *head);
169 struct bio *bioq_takefirst(struct bio_queue_head *head);
170 void bioq_flush(struct bio_queue_head *head, struct devstat *stp, int error);
171 void bioq_init(struct bio_queue_head *head);
172 void bioq_insert_head(struct bio_queue_head *head, struct bio *bp);
173 void bioq_insert_tail(struct bio_queue_head *head, struct bio *bp);
174 void bioq_remove(struct bio_queue_head *head, struct bio *bp);
175 
176 int	physio(struct cdev *dev, struct uio *uio, int ioflag);
177 #define physread physio
178 #define physwrite physio
179 
180 #endif /* _KERNEL */
181 
182 #endif /* !_SYS_BIO_H_ */
183