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subr_disk_open.c revision 1.6.2.1 
      1 /*	$NetBSD: subr_disk_open.c,v 1.6.2.1 2012/04/29 23:05:05 mrg 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 1.6.2.1 2012/04/29 23:05:05 mrg 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 	devmajor_t bmajor;
     46 	int unit;
     47 	struct vnode *tmpvn;
     48 	int error;
     49 	dev_t dev;
     50 
     51 	/*
     52 	 * Lookup major number for disk block device.
     53 	 */
     54 	bmajor = devsw_name2blk(device_xname(dv), NULL, 0);
     55 	if (bmajor == -1)
     56 		return NULL;
     57 
     58 	unit = device_unit(dv);
     59 	/*
     60 	 * Fake a temporary vnode for the disk, open it, and read
     61 	 * and hash the sectors.
     62 	 */
     63 	dev = device_is_a(dv, "dk") ? makedev(bmajor, unit) :
     64 	    MAKEDISKDEV(bmajor, unit, RAW_PART);
     65 	if (bdevvp(dev, &tmpvn))
     66 		panic("%s: can't alloc vnode for %s", __func__,
     67 		    device_xname(dv));
     68 	error = VOP_OPEN(tmpvn, FREAD | FSILENT, NOCRED);
     69 	if (error) {
     70 		/*
     71 		 * Ignore errors caused by missing device, partition,
     72 		 * medium, or busy [presumably because of a wedge covering it]
     73 		 */
     74 		switch (error) {
     75 		case ENXIO:
     76 		case ENODEV:
     77 		case EBUSY:
     78 			break;
     79 		default:
     80 			printf("%s: can't open dev %s (%d)\n",
     81 			    __func__, device_xname(dv), error);
     82 			break;
     83 		}
     84 		vput(tmpvn);
     85 		return NULL;
     86 	}
     87 
     88 	return tmpvn;
     89 }
     90 
     91 int
     92 getdisksize(struct vnode *vp, uint64_t *numsecp, unsigned *secsizep)
     93 {
     94 	struct partinfo dpart;
     95 	struct dkwedge_info dkw;
     96 	struct disk *pdk;
     97 	int error;
     98 
     99 	error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED);
    100 	if (error == 0) {
    101 		*secsizep = dpart.disklab->d_secsize;
    102 		*numsecp  = dpart.part->p_size;
    103 		return 0;
    104 	}
    105 
    106 	error = VOP_IOCTL(vp, DIOCGWEDGEINFO, &dkw, FREAD, NOCRED);
    107 	if (error == 0) {
    108 		pdk = disk_find(dkw.dkw_parent);
    109 		if (pdk != NULL) {
    110 			*secsizep = DEV_BSIZE << pdk->dk_blkshift;
    111 			*numsecp  = dkw.dkw_size;
    112 		} else
    113 			error = ENODEV;
    114 	}
    115 
    116 	return error;
    117 }
    118 
    119 int
    120 getdiskinfo(struct vnode *vp, struct dkwedge_info *dkw)
    121 {
    122 	struct partinfo dpart;
    123 	int error;
    124 	dev_t dev = vp->v_specnode->sn_rdev;
    125 
    126 	if (VOP_IOCTL(vp, DIOCGWEDGEINFO, dkw, FREAD, NOCRED) == 0)
    127 		return 0;
    128 
    129 	if ((error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED)) != 0)
    130 		return error;
    131 
    132 	snprintf(dkw->dkw_devname, sizeof(dkw->dkw_devname), "%s%" PRId32 "%c",
    133 	    devsw_blk2name(major(dev)), DISKUNIT(dev), (char)DISKPART(dev) +
    134 	    'a');
    135 
    136 	dkw->dkw_wname[0] = '\0';
    137 
    138 	strlcpy(dkw->dkw_parent, dkw->dkw_devname, sizeof(dkw->dkw_parent));
    139 
    140 	dkw->dkw_size = dpart.part->p_size;
    141 	dkw->dkw_offset = dpart.part->p_offset;
    142 
    143 	strlcpy(dkw->dkw_ptype, getfstypename(dpart.part->p_fstype),
    144 	    sizeof(dkw->dkw_ptype));
    145 
    146 	return 0;
    147 }
    148