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subr_disk_open.c revision 1.3.2.1 
      1 /*	$NetBSD: subr_disk_open.c,v 1.3.2.1 2012/04/17 00:08:27 yamt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: subr_disk_open.c,v 1.3.2.1 2012/04/17 00:08:27 yamt Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/conf.h>
     34 #include <sys/device.h>
     35 #include <sys/disk.h>
     36 #include <sys/disklabel.h>
     37 #include <sys/fcntl.h>
     38 #include <sys/kauth.h>
     39 #include <sys/vnode.h>
     40 #include <miscfs/specfs/specdev.h>
     41 
     42 struct vnode *
     43 opendisk(struct device *dv)
     44 {
     45 	int bmajor, bminor;
     46 	struct vnode *tmpvn;
     47 	int error;
     48 	dev_t dev;
     49 
     50 	/*
     51 	 * Lookup major number for disk block device.
     52 	 */
     53 	bmajor = devsw_name2blk(device_xname(dv), NULL, 0);
     54 	if (bmajor == -1)
     55 		return NULL;
     56 
     57 	bminor = minor(device_unit(dv));
     58 	/*
     59 	 * Fake a temporary vnode for the disk, open it, and read
     60 	 * and hash the sectors.
     61 	 */
     62 	dev = device_is_a(dv, "dk") ? makedev(bmajor, bminor) :
     63 	    MAKEDISKDEV(bmajor, bminor, RAW_PART);
     64 	if (bdevvp(dev, &tmpvn))
     65 		panic("%s: can't alloc vnode for %s", __func__,
     66 		    device_xname(dv));
     67 	error = VOP_OPEN(tmpvn, FREAD | FSILENT, NOCRED);
     68 	if (error) {
     69 		/*
     70 		 * Ignore errors caused by missing device, partition,
     71 		 * medium, or busy [presumably because of a wedge covering it]
     72 		 */
     73 		switch (error) {
     74 		case ENXIO:
     75 		case ENODEV:
     76 		case EBUSY:
     77 			break;
     78 		default:
     79 			printf("%s: can't open dev %s (%d)\n",
     80 			    __func__, device_xname(dv), error);
     81 			break;
     82 		}
     83 		vput(tmpvn);
     84 		return NULL;
     85 	}
     86 
     87 	return tmpvn;
     88 }
     89 
     90 int
     91 getdisksize(struct vnode *vp, uint64_t *numsecp, unsigned *secsizep)
     92 {
     93 	struct partinfo dpart;
     94 	struct dkwedge_info dkw;
     95 	struct disk *pdk;
     96 	int error;
     97 
     98 	error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED);
     99 	if (error == 0) {
    100 		*secsizep = dpart.disklab->d_secsize;
    101 		*numsecp  = dpart.part->p_size;
    102 		return 0;
    103 	}
    104 
    105 	error = VOP_IOCTL(vp, DIOCGWEDGEINFO, &dkw, FREAD, NOCRED);
    106 	if (error == 0) {
    107 		pdk = disk_find(dkw.dkw_parent);
    108 		if (pdk != NULL) {
    109 			*secsizep = DEV_BSIZE << pdk->dk_blkshift;
    110 			*numsecp  = dkw.dkw_size;
    111 		} else
    112 			error = ENODEV;
    113 	}
    114 
    115 	return error;
    116 }
    117 
    118 int
    119 getdiskinfo(struct vnode *vp, struct dkwedge_info *dkw)
    120 {
    121 	struct partinfo dpart;
    122 	int error;
    123 	dev_t dev = vp->v_specnode->sn_rdev;
    124 
    125 	if (VOP_IOCTL(vp, DIOCGWEDGEINFO, dkw, FREAD, NOCRED) == 0)
    126 		return 0;
    127 
    128 	if ((error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED)) != 0)
    129 		return error;
    130 
    131 	snprintf(dkw->dkw_devname, sizeof(dkw->dkw_devname), "%s%" PRId32 "%c",
    132 	    devsw_blk2name(major(dev)), DISKUNIT(dev), (char)DISKPART(dev) +
    133 	    'a');
    134 
    135 	dkw->dkw_wname[0] = '\0';
    136 
    137 	strlcpy(dkw->dkw_parent, dkw->dkw_devname, sizeof(dkw->dkw_parent));
    138 
    139 	dkw->dkw_size = dpart.part->p_size;
    140 	dkw->dkw_offset = dpart.part->p_offset;
    141 
    142 	strlcpy(dkw->dkw_ptype, getfstypename(dpart.part->p_fstype),
    143 	    sizeof(dkw->dkw_ptype));
    144 
    145 	return 0;
    146 }
    147