xref: /openbsd-src/sys/dev/diskmap.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*	$OpenBSD: diskmap.c,v 1.7 2012/04/22 05:43:14 guenther Exp $	*/
2 
3 /*
4  * Copyright (c) 2009, 2010 Joel Sing <jsing@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 /*
20  * Disk mapper.
21  */
22 
23 #include <sys/param.h>
24 #include <sys/types.h>
25 #include <sys/systm.h>
26 #include <sys/device.h>
27 #include <sys/errno.h>
28 #include <sys/buf.h>
29 #include <sys/conf.h>
30 #include <sys/dkio.h>
31 #include <sys/disk.h>
32 #include <sys/disklabel.h>
33 #include <sys/file.h>
34 #include <sys/filedesc.h>
35 #include <sys/malloc.h>
36 #include <sys/namei.h>
37 #include <sys/proc.h>
38 #include <sys/vnode.h>
39 
40 int
41 diskmapopen(dev_t dev, int flag, int fmt, struct proc *p)
42 {
43 	return 0;
44 }
45 
46 int
47 diskmapclose(dev_t dev, int flag, int fmt, struct proc *p)
48 {
49 	return 0;
50 }
51 
52 int
53 diskmapioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
54 {
55 	struct dk_diskmap *dm;
56 	struct nameidata ndp;
57 	struct filedesc *fdp;
58 	struct file *fp = NULL;
59 	struct vnode *vp = NULL, *ovp;
60 	char *devname;
61 	int fd, error = EINVAL;
62 
63 	if (cmd != DIOCMAP)
64 		return EINVAL;
65 
66 	/*
67 	 * Map a request for a disk to the correct device. We should be
68 	 * supplied with either a diskname or a disklabel UID.
69 	 */
70 
71 	dm = (struct dk_diskmap *)addr;
72 	fd = dm->fd;
73 	devname = malloc(PATH_MAX, M_DEVBUF, M_WAITOK);
74 	if (copyinstr(dm->device, devname, PATH_MAX, NULL))
75 		goto invalid;
76 	if (disk_map(devname, devname, PATH_MAX, dm->flags) == 0)
77 		if (copyoutstr(devname, dm->device, PATH_MAX, NULL))
78 			goto invalid;
79 
80 	/* Attempt to open actual device. */
81 	fdp = p->p_fd;
82 	fdplock(fdp);
83 
84 	if ((error = getvnode(fdp, fd, &fp)) != 0)
85 		goto bad;
86 
87 	ndp.ni_segflg = UIO_SYSSPACE;
88 	ndp.ni_dirfd = AT_FDCWD;
89 	ndp.ni_dirp = devname;
90 	ndp.ni_cnd.cn_proc = p;
91 	if ((error = vn_open(&ndp, fp->f_flag, 0)) != 0)
92 		goto bad;
93 
94 	vp = ndp.ni_vp;
95 
96 	/* Close the original vnode. */
97 	ovp = (struct vnode *)fp->f_data;
98 	if (fp->f_flag & FWRITE)
99 		ovp->v_writecount--;
100 
101 	if (ovp->v_writecount == 0) {
102 		vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, p);
103 		VOP_CLOSE(ovp, fp->f_flag, p->p_ucred, p);
104 		vput(ovp);
105 	}
106 
107 	fp->f_type = DTYPE_VNODE;
108 	fp->f_ops = &vnops;
109 	fp->f_data = (caddr_t)vp;
110 	fp->f_offset = 0;
111 	fp->f_rxfer = 0;
112 	fp->f_wxfer = 0;
113 	fp->f_seek = 0;
114 	fp->f_rbytes = 0;
115 	fp->f_wbytes = 0;
116 
117 	VOP_UNLOCK(vp, 0, p);
118 
119 	FRELE(fp, p);
120 	fdpunlock(fdp);
121 	free(devname, M_DEVBUF);
122 
123 	return 0;
124 
125 bad:
126 	if (vp)
127 		vput(vp);
128 	if (fp)
129 		FRELE(fp, p);
130 
131 	fdpunlock(fdp);
132 
133 invalid:
134 	free(devname, M_DEVBUF);
135 
136 	return (error);
137 }
138 
139 int
140 diskmapread(dev_t dev, struct uio *uio, int flag)
141 {
142 	return ENXIO;
143 }
144 
145 int
146 diskmapwrite(dev_t dev, struct uio *uio, int flag)
147 {
148 	return ENXIO;
149 }
150