/*      $NetBSD: subr_disk_open.c,v 1.15 2020/02/29 14:44:44 mlelstv Exp $      */

/*-
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_disk_open.c,v 1.15 2020/02/29 14:44:44 mlelstv Exp $");

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/fcntl.h>
#include <sys/kauth.h>
#include <sys/vnode.h>
#include <miscfs/specfs/specdev.h>

struct vnode *
opendisk(device_t dv)
{
       devmajor_t bmajor;
       int unit;
       struct vnode *tmpvn;
       int error;
       dev_t dev;

       /*
        * Lookup major number for disk block device.
        */
       bmajor = devsw_name2blk(device_xname(dv), NULL, 0);
       if (bmajor == -1)
               return NULL;

       unit = device_unit(dv);
       /*
        * Fake a temporary vnode for the disk, open it, and read
        * and hash the sectors.
        */
       dev = device_is_a(dv, "dk") ? makedev(bmajor, unit) :
           MAKEDISKDEV(bmajor, unit, RAW_PART);
       if (bdevvp(dev, &tmpvn))
               panic("%s: can't alloc vnode for %s", __func__,
                   device_xname(dv));
       vn_lock(tmpvn, LK_EXCLUSIVE | LK_RETRY);
       error = VOP_OPEN(tmpvn, FREAD | FSILENT, NOCRED);
       if (error) {
               /*
                * Ignore errors caused by missing device, partition,
                * medium, or busy [presumably because of a wedge covering it]
                */
               switch (error) {
               case ENXIO:
               case ENODEV:
               case EBUSY:
                       break;
               default:
                       printf("%s: can't open dev %s (%d)\n",
                           __func__, device_xname(dv), error);
                       break;
               }
               vput(tmpvn);
               return NULL;
       }

       return tmpvn;
}

int
getdisksize(struct vnode *vp, uint64_t *numsecp, unsigned int *secsizep)
{
       struct partinfo pi;
       struct dkwedge_info dkw;
       struct disk *pdk;
       unsigned int secsize;
       uint64_t numsec;
       int error;

       /*
        * We attempt to get the wedge information first if it exists,
        * because the label does not support larger size disks.
        */
       error = VOP_IOCTL(vp, DIOCGWEDGEINFO, &dkw, FREAD, NOCRED);
       if (error == 0) {
               pdk = disk_find(dkw.dkw_parent);
               if (pdk != NULL) {
                       secsize = DEV_BSIZE << pdk->dk_blkshift;
                       numsec  = dkw.dkw_size;
               } else
                       error = ENODEV;
       }

       if (error) {
               error = VOP_IOCTL(vp, DIOCGPARTINFO, &pi, FREAD, NOCRED);
               if (error == 0) {
                       secsize = pi.pi_secsize;
                       numsec  = pi.pi_size;
               }
       }

       if (error == 0 &&
           (secsize == 0 || secsize > MAXBSIZE || !powerof2(secsize) ||
            numsec == 0)) {
#ifdef DIAGNOSTIC
               printf("%s: %s returns invalid disksize values"
                   " (secsize = %u, numsec = %" PRIu64 ")\n",
                   __func__,
                   devsw_blk2name(major(vp->v_specnode->sn_rdev)),
                   secsize, numsec);
#endif
               error = EINVAL;
       }
       if (error == 0) {
               *secsizep = secsize;
               *numsecp  = numsec;
       }

       return error;
}

int
getdiskinfo(struct vnode *vp, struct dkwedge_info *dkw)
{
       struct partinfo pi;
       int error;
       dev_t dev = vp->v_specnode->sn_rdev;

       if (VOP_IOCTL(vp, DIOCGWEDGEINFO, dkw, FREAD, NOCRED) == 0)
               return 0;

       if ((error = VOP_IOCTL(vp, DIOCGPARTINFO, &pi, FREAD, NOCRED)) != 0)
               return error;

       snprintf(dkw->dkw_devname, sizeof(dkw->dkw_devname), "%s%" PRId32 "%c",
           devsw_blk2name(major(dev)), DISKUNIT(dev), (char)DISKPART(dev) +
           'a');

       dkw->dkw_wname[0] = '\0';

       snprintf(dkw->dkw_parent, sizeof(dkw->dkw_parent), "%s%" PRId32,
           devsw_blk2name(major(dev)), DISKUNIT(dev));

       dkw->dkw_size = pi.pi_size;
       dkw->dkw_offset = pi.pi_offset;
       strlcpy(dkw->dkw_ptype, getfstypename(pi.pi_fstype),
           sizeof(dkw->dkw_ptype));

       return 0;
}