756 lines
21 KiB
C
756 lines
21 KiB
C
/*-
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* Copyright (c) 2002 Poul-Henning Kamp
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* Copyright (c) 2002 Networks Associates Technology, Inc.
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* All rights reserved.
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*
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* This software was developed for the FreeBSD Project by Poul-Henning Kamp
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* and NAI Labs, the Security Research Division of Network Associates, Inc.
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* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
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* DARPA CHATS research program.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The names of the authors may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*
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* This is the method for dealing with BSD disklabels. It has been
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* extensively (by my standards at least) commented, in the vain hope that
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* it will server as the source in future copy&paste operations.
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*/
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#include <sys/param.h>
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#ifndef _KERNEL
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <signal.h>
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#include <err.h>
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#else
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/conf.h>
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#include <sys/bio.h>
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#include <sys/malloc.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#endif
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#include <sys/stdint.h>
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#include <sys/errno.h>
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#include <sys/disklabel.h>
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#include <geom/geom.h>
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#include <geom/geom_slice.h>
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#define BSD_CLASS_NAME "BSD"
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/*
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* Our private data about one instance. All the rest is handled by the
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* slice code and stored in the its softc, so this is just the stuff
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* specific to BSD disklabels.
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*/
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struct g_bsd_softc {
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off_t labeloffset;
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off_t rawoffset;
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struct disklabel ondisk;
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struct disklabel inram;
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};
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/*
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* The next 4 functions isolate us from how the compiler lays out and pads
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* "struct disklabel". We treat what we read from disk as a bytestream and
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* explicitly convert it into a struct disklabel. This makes us compiler-
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* endianes- and wordsize- agnostic.
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* For now we only have little-endian formats to deal with.
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*/
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static void
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g_bsd_ledec_partition(u_char *ptr, struct partition *d)
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{
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d->p_size = g_dec_le4(ptr + 0);
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d->p_offset = g_dec_le4(ptr + 4);
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d->p_fsize = g_dec_le4(ptr + 8);
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d->p_fstype = ptr[12];
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d->p_frag = ptr[13];
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d->p_cpg = g_dec_le2(ptr + 14);
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}
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static void
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g_bsd_ledec_disklabel(u_char *ptr, struct disklabel *d)
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{
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int i;
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d->d_magic = g_dec_le4(ptr + 0);
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d->d_type = g_dec_le2(ptr + 4);
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d->d_subtype = g_dec_le2(ptr + 6);
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bcopy(ptr + 8, d->d_typename, 16);
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bcopy(ptr + 24, d->d_packname, 16);
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d->d_secsize = g_dec_le4(ptr + 40);
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d->d_nsectors = g_dec_le4(ptr + 44);
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d->d_ntracks = g_dec_le4(ptr + 48);
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d->d_ncylinders = g_dec_le4(ptr + 52);
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d->d_secpercyl = g_dec_le4(ptr + 56);
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d->d_secperunit = g_dec_le4(ptr + 60);
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d->d_sparespertrack = g_dec_le2(ptr + 64);
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d->d_sparespercyl = g_dec_le2(ptr + 66);
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d->d_acylinders = g_dec_le4(ptr + 68);
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d->d_rpm = g_dec_le2(ptr + 72);
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d->d_interleave = g_dec_le2(ptr + 74);
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d->d_trackskew = g_dec_le2(ptr + 76);
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d->d_cylskew = g_dec_le2(ptr + 78);
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d->d_headswitch = g_dec_le4(ptr + 80);
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d->d_trkseek = g_dec_le4(ptr + 84);
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d->d_flags = g_dec_le4(ptr + 88);
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d->d_drivedata[0] = g_dec_le4(ptr + 92);
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d->d_drivedata[1] = g_dec_le4(ptr + 96);
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d->d_drivedata[2] = g_dec_le4(ptr + 100);
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d->d_drivedata[3] = g_dec_le4(ptr + 104);
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d->d_drivedata[4] = g_dec_le4(ptr + 108);
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d->d_spare[0] = g_dec_le4(ptr + 112);
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d->d_spare[1] = g_dec_le4(ptr + 116);
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d->d_spare[2] = g_dec_le4(ptr + 120);
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d->d_spare[3] = g_dec_le4(ptr + 124);
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d->d_spare[4] = g_dec_le4(ptr + 128);
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d->d_magic2 = g_dec_le4(ptr + 132);
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d->d_checksum = g_dec_le2(ptr + 136);
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d->d_npartitions = g_dec_le2(ptr + 138);
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d->d_bbsize = g_dec_le4(ptr + 140);
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d->d_sbsize = g_dec_le4(ptr + 144);
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for (i = 0; i < MAXPARTITIONS; i++)
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g_bsd_ledec_partition(ptr + 148 + 16 * i, &d->d_partitions[i]);
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}
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static void
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g_bsd_leenc_partition(u_char *ptr, struct partition *d)
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{
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g_enc_le4(ptr + 0, d->p_size);
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g_enc_le4(ptr + 4, d->p_offset);
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g_enc_le4(ptr + 8, d->p_fsize);
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ptr[12] = d->p_fstype;
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ptr[13] = d->p_frag;
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g_enc_le2(ptr + 14, d->p_cpg);
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}
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static void
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g_bsd_leenc_disklabel(u_char *ptr, struct disklabel *d)
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{
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int i;
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g_enc_le4(ptr + 0, d->d_magic);
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g_enc_le2(ptr + 4, d->d_type);
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g_enc_le2(ptr + 6, d->d_subtype);
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bcopy(d->d_typename, ptr + 8, 16);
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bcopy(d->d_packname, ptr + 24, 16);
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g_enc_le4(ptr + 40, d->d_secsize);
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g_enc_le4(ptr + 44, d->d_nsectors);
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g_enc_le4(ptr + 48, d->d_ntracks);
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g_enc_le4(ptr + 52, d->d_ncylinders);
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g_enc_le4(ptr + 56, d->d_secpercyl);
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g_enc_le4(ptr + 60, d->d_secperunit);
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g_enc_le2(ptr + 64, d->d_sparespertrack);
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g_enc_le2(ptr + 66, d->d_sparespercyl);
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g_enc_le4(ptr + 68, d->d_acylinders);
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g_enc_le2(ptr + 72, d->d_rpm);
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g_enc_le2(ptr + 74, d->d_interleave);
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g_enc_le2(ptr + 76, d->d_trackskew);
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g_enc_le2(ptr + 78, d->d_cylskew);
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g_enc_le4(ptr + 80, d->d_headswitch);
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g_enc_le4(ptr + 84, d->d_trkseek);
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g_enc_le4(ptr + 88, d->d_flags);
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g_enc_le4(ptr + 92, d->d_drivedata[0]);
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g_enc_le4(ptr + 96, d->d_drivedata[1]);
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g_enc_le4(ptr + 100, d->d_drivedata[2]);
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g_enc_le4(ptr + 104, d->d_drivedata[3]);
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g_enc_le4(ptr + 108, d->d_drivedata[4]);
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g_enc_le4(ptr + 112, d->d_spare[0]);
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g_enc_le4(ptr + 116, d->d_spare[1]);
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g_enc_le4(ptr + 120, d->d_spare[2]);
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g_enc_le4(ptr + 124, d->d_spare[3]);
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g_enc_le4(ptr + 128, d->d_spare[4]);
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g_enc_le4(ptr + 132, d->d_magic2);
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g_enc_le2(ptr + 136, d->d_checksum);
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g_enc_le2(ptr + 138, d->d_npartitions);
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g_enc_le4(ptr + 140, d->d_bbsize);
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g_enc_le4(ptr + 144, d->d_sbsize);
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for (i = 0; i < MAXPARTITIONS; i++)
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g_bsd_leenc_partition(ptr + 148 + 16 * i, &d->d_partitions[i]);
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}
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/*
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* For reasons which were valid and just in their days, FreeBSD/i386 uses
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* absolute disk-addresses in disklabels. The way it works is that the
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* p_offset field of all partitions have the first sector number of the
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* disk slice added to them. This was hidden kernel-magic, userland did
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* not see these offsets. These two functions subtract and add them
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* while converting from the "ondisk" to the "inram" labels and vice
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* versa.
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*/
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static void
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ondisk2inram(struct g_bsd_softc *sc)
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{
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struct partition *ppp;
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struct disklabel *dl;
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int i;
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sc->inram = sc->ondisk;
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dl= &sc->inram;
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/* Basic sanity-check needed to avoid mistakes */
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if (dl->d_magic != DISKMAGIC || dl->d_magic2 != DISKMAGIC)
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return;
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if (dl->d_npartitions > MAXPARTITIONS)
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return;
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sc->rawoffset = dl->d_partitions[RAW_PART].p_offset;
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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if (ppp->p_size != 0 && ppp->p_offset < sc->rawoffset)
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sc->rawoffset = 0;
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}
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if (sc->rawoffset > 0) {
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if (dl->d_partitions[RAW_PART].p_size +
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sc->rawoffset == dl->d_secperunit) {
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}
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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ppp->p_offset -= sc->rawoffset;
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}
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}
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dl->d_checksum = 0;
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dl->d_checksum = dkcksum(&sc->inram);
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}
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static void
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inram2ondisk(struct g_bsd_softc *sc)
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{
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struct partition *ppp;
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int i;
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sc->ondisk = sc->inram;
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if (sc->rawoffset != 0) {
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for (i = 0; i < sc->inram.d_npartitions; i++) {
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ppp = &sc->ondisk.d_partitions[i];
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ppp->p_offset += sc->rawoffset;
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}
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}
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sc->ondisk.d_checksum = 0;
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sc->ondisk.d_checksum = dkcksum(&sc->ondisk);
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}
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/*
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* Check that this looks like a valid disklabel, but be prepared
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* to get any kind of junk. The checksum must be checked only
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* after this function returns success to prevent a bogus d_npartitions
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* value from tripping us up.
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*/
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static int
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g_bsd_checklabel(struct disklabel *dl)
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{
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struct partition *ppp;
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int i;
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if (dl->d_magic != DISKMAGIC || dl->d_magic2 != DISKMAGIC)
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return(EINVAL);
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/*
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* If the label specifies more partitions than we can handle
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* we have to reject it: If people updated the label they would
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* trash it, and that would break the checksum.
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*/
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if (dl->d_npartitions > MAXPARTITIONS)
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return(EINVAL);
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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/* Cannot extend past unit */
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if (ppp->p_size != 0 &&
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ppp->p_offset + ppp->p_size > dl->d_secperunit) {
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return(EINVAL);
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}
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}
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return(0);
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}
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/*
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* Modify our slicer to match proposed disklabel, if possible.
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* First carry out all the simple checks, then lock topology
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* and check that no open providers are affected negatively
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* then carry out all the changes.
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*
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* NB: Returns with topology held only if successful return.
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*/
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static int
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g_bsd_modify(struct g_geom *gp, struct disklabel *dl)
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{
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int i, error;
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struct partition *ppp;
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struct g_slicer *gsp;
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struct g_consumer *cp;
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u_int secsize;
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off_t mediasize;
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/* Basic check that this is indeed a disklabel */
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error = g_bsd_checklabel(dl);
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if (error)
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return(error);
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/* Make sure the checksum is OK */
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if (dkcksum(dl) != 0)
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return(EINVAL);
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/* Get dimensions of our device */
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cp = LIST_FIRST(&gp->consumer);
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error = g_getattr("GEOM::sectorsize", cp, &secsize);
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if (error)
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return(error);
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error = g_getattr("GEOM::mediasize", cp, &mediasize);
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if (error)
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return(error);
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#ifdef nolonger
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/*
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* The raw-partition must start at zero. We do not check that the
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* size == mediasize because this is overly restrictive. We have
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* already tested in g_bsd_checklabel() that it is not longer.
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* XXX: RAW_PART is archaic anyway, and we should drop it.
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*/
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if (dl->d_partitions[RAW_PART].p_offset != 0)
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return (EINVAL);
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#endif
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#ifdef notyet
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/*
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* Indications are that the d_secperunit is not correctly
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* initialized in many cases, and since we don't need it
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* for anything, we dont strictly need this test.
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* Preemptive action to avoid confusing people in disklabel(8)
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* may be in order.
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*/
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/* The label cannot claim a larger size than the media */
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if ((off_t)dl->d_secperunit * dl->d_secsize > mediasize)
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return (EINVAL);
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#endif
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/* ... or a smaller sector size */
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if (dl->d_secsize < secsize)
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return (EINVAL);
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/* ... or a non-multiple sector size */
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if (dl->d_secsize % secsize != 0)
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return (EINVAL);
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g_topology_lock();
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/* Don't munge open parititions */
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gsp = gp->softc;
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
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(off_t)ppp->p_offset * dl->d_secsize,
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(off_t)ppp->p_size * dl->d_secsize,
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"%s%c", gp->name, 'a' + i);
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if (error) {
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g_topology_unlock();
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return (error);
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}
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}
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/* Look good, go for it... */
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for (i = 0; i < gsp->nslice; i++) {
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ppp = &dl->d_partitions[i];
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g_slice_config(gp, i, G_SLICE_CONFIG_SET,
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(off_t)ppp->p_offset * dl->d_secsize,
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(off_t)ppp->p_size * dl->d_secsize,
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"%s%c", gp->name, 'a' + i);
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}
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return (0);
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}
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/*
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* Calculate a disklabel checksum for a little-endian byte-stream.
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* We need access to the decoded disklabel because the checksum only
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* covers the partition data for the first d_npartitions.
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*/
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static int
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g_bsd_lesum(struct disklabel *dl, u_char *p)
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{
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u_char *pe;
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uint16_t sum;
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pe = p + 148 + 16 * dl->d_npartitions;
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sum = 0;
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while (p < pe) {
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sum ^= g_dec_le2(p);
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p += 2;
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}
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return (sum);
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}
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/*
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* This is an internal helper function, called multiple times from the taste
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* function to try to locate a disklabel on the disk. More civilized formats
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* will not need this, as there is only one possible place on disk to look
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* for the magic spot.
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*/
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static int
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g_bsd_try(struct g_slicer *gsp, struct g_consumer *cp, int secsize, struct g_bsd_softc *ms, off_t offset)
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{
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int error;
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u_char *buf;
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struct disklabel *dl;
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off_t secoff;
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/*
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* We need to read entire aligned sectors, and we assume that the
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* disklabel does not span sectors, so one sector is enough.
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*/
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error = 0;
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secoff = offset % secsize;
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buf = g_read_data(cp, offset - secoff, secsize, &error);
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if (buf == NULL || error != 0)
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return(ENOENT);
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/* Decode into our native format */
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dl = &ms->ondisk;
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g_bsd_ledec_disklabel(buf + secoff, dl);
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ondisk2inram(ms);
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dl = &ms->inram;
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/* Does it look like a label at all ? */
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if (g_bsd_checklabel(dl))
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error = ENOENT;
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/* ... and does the raw data have a good checksum ? */
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if (error == 0 && g_bsd_lesum(dl, buf + secoff) != 0)
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error = ENOENT;
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/* Remember to free the buffer g_read_data() gave us */
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g_free(buf);
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/* If we had a label, record it properly */
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if (error == 0) {
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gsp->frontstuff = 16 * secsize; /* XXX */
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ms->labeloffset = offset;
|
|
}
|
|
return(error);
|
|
}
|
|
|
|
/*
|
|
* Implement certain ioctls to modify disklabels with. This function
|
|
* is called by the event handler thread with topology locked as result
|
|
* of the g_call_me() in g_bsd_start(). It is not necessary to keep
|
|
* topology locked all the time but make sure to return with topology
|
|
* locked as well.
|
|
*/
|
|
|
|
static void
|
|
g_bsd_ioctl(void *arg)
|
|
{
|
|
struct bio *bp;
|
|
struct g_geom *gp;
|
|
struct g_slicer *gsp;
|
|
struct g_bsd_softc *ms;
|
|
struct disklabel *dl;
|
|
struct g_ioctl *gio;
|
|
struct g_consumer *cp;
|
|
u_char *buf;
|
|
off_t secoff;
|
|
u_int secsize;
|
|
int error;
|
|
|
|
/* We don't need topology for now */
|
|
g_topology_unlock();
|
|
|
|
/* Get hold of the interesting bits from the bio */
|
|
bp = arg;
|
|
gp = bp->bio_to->geom;
|
|
gsp = gp->softc;
|
|
ms = gsp->softc;
|
|
gio = (struct g_ioctl *)bp->bio_data;
|
|
|
|
/* The disklabel to set is the ioctl argument */
|
|
dl = gio->data;
|
|
|
|
/* Validate and modify our slice instance to match */
|
|
error = g_bsd_modify(gp, dl); /* picks up topology lock on success */
|
|
if (error) {
|
|
g_topology_lock();
|
|
g_io_deliver(bp, error);
|
|
return;
|
|
}
|
|
/* Update our copy of the disklabel */
|
|
ms->inram = *dl;
|
|
inram2ondisk(ms);
|
|
|
|
if (gio->cmd == DIOCSDINFO) {
|
|
g_io_deliver(bp, 0);
|
|
return;
|
|
}
|
|
KASSERT(gio->cmd == DIOCWDINFO, ("Unknown ioctl in g_bsd_ioctl"));
|
|
cp = LIST_FIRST(&gp->consumer);
|
|
/* Get sector size, we need it to read data. */
|
|
error = g_getattr("GEOM::sectorsize", cp, &secsize);
|
|
if (error || secsize < 512) {
|
|
g_io_deliver(bp, error);
|
|
return;
|
|
}
|
|
secoff = ms->labeloffset % secsize;
|
|
buf = g_read_data(cp, ms->labeloffset - secoff, secsize, &error);
|
|
if (buf == NULL || error != 0) {
|
|
g_io_deliver(bp, error);
|
|
return;
|
|
}
|
|
dl = &ms->ondisk;
|
|
g_bsd_leenc_disklabel(buf + secoff, dl);
|
|
error = g_write_data(cp, ms->labeloffset - secoff, buf, secsize);
|
|
g_free(buf);
|
|
g_io_deliver(bp, error);
|
|
return;
|
|
}
|
|
|
|
/*-
|
|
* This start routine is only called for non-trivial requests, all the
|
|
* trivial ones are handled autonomously by the slice code.
|
|
* For requests we handle here, we must call the g_io_deliver() on the
|
|
* bio, and return non-zero to indicate to the slice code that we did so.
|
|
* This code executes in the "DOWN" I/O path, this means:
|
|
* * No sleeping.
|
|
* * Don't grab the topology lock.
|
|
* * Don't call biowait, g_getattr(), g_setattr() or g_read_data()
|
|
*/
|
|
|
|
static int
|
|
g_bsd_start(struct bio *bp)
|
|
{
|
|
struct g_geom *gp;
|
|
struct g_bsd_softc *ms;
|
|
struct g_slicer *gsp;
|
|
struct g_ioctl *gio;
|
|
int error;
|
|
|
|
gp = bp->bio_to->geom;
|
|
gsp = gp->softc;
|
|
ms = gsp->softc;
|
|
|
|
/* We only handle ioctl(2) requests of the right format. */
|
|
if (strcmp(bp->bio_attribute, "GEOM::ioctl"))
|
|
return(0);
|
|
else if (bp->bio_length != sizeof *gio)
|
|
return(0);
|
|
|
|
/* Get hold of the ioctl parameters */
|
|
gio = (struct g_ioctl *)bp->bio_data;
|
|
|
|
switch(gio->cmd) {
|
|
case DIOCGDINFO:
|
|
/* Return a copy of the disklabel to userland */
|
|
bcopy(&ms->inram, gio->data, sizeof ms->inram);
|
|
g_io_deliver(bp, 0);
|
|
return (1);
|
|
case DIOCSDINFO:
|
|
case DIOCWDINFO:
|
|
/*
|
|
* These we cannot do without the topology lock and some
|
|
* some I/O requests. Ask the event-handler to schedule
|
|
* us in a less restricted environment.
|
|
*/
|
|
error = g_call_me(g_bsd_ioctl, bp);
|
|
if (error)
|
|
g_io_deliver(bp, error);
|
|
/*
|
|
* We must return non-zero to indicate that we will deal
|
|
* with this bio, even though we have not done so yet.
|
|
*/
|
|
return (1);
|
|
default:
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Dump configuration information in XML format.
|
|
* Notice that the function is called once for the geom and once for each
|
|
* consumer and provider. We let g_slice_dumpconf() do most of the work.
|
|
*/
|
|
static void
|
|
g_bsd_dumpconf(struct sbuf *sb, char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
|
|
{
|
|
struct g_bsd_softc *ms;
|
|
struct g_slicer *gsp;
|
|
|
|
gsp = gp->softc;
|
|
ms = gsp->softc;
|
|
if (pp == NULL && cp == NULL) {
|
|
sbuf_printf(sb, "%s<labeloffset>%jd</labeloffset>\n",
|
|
indent, (intmax_t)ms->labeloffset);
|
|
}
|
|
g_slice_dumpconf(sb, indent, gp, cp, pp);
|
|
}
|
|
|
|
/*
|
|
* The taste function is called from the event-handler, with the topology
|
|
* lock already held and a provider to examine. The flags are unused.
|
|
*
|
|
* If flags == G_TF_NORMAL, the idea is to take a bite of the provider and
|
|
* if we find valid, consistent magic on it, build a geom on it.
|
|
* any magic bits which indicate that we should automatically put a BSD
|
|
* geom on it.
|
|
*
|
|
* There may be cases where the operator would like to put a BSD-geom on
|
|
* providers which do not meet all of the requirements. This can be done
|
|
* by instead passing the G_TF_INSIST flag, which will override these
|
|
* checks.
|
|
*
|
|
* The final flags value is G_TF_TRANSPARENT, which instructs the method
|
|
* to put a geom on top of the provider and configure it to be as transparent
|
|
* as possible. This is not really relevant to the BSD method and therefore
|
|
* not implemented here.
|
|
*/
|
|
|
|
static struct g_geom *
|
|
g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags)
|
|
{
|
|
struct g_geom *gp;
|
|
struct g_consumer *cp;
|
|
int error, i;
|
|
struct g_bsd_softc *ms;
|
|
struct disklabel *dl;
|
|
u_int secsize;
|
|
struct g_slicer *gsp;
|
|
|
|
g_trace(G_T_TOPOLOGY, "bsd_taste(%s,%s)", mp->name, pp->name);
|
|
g_topology_assert();
|
|
|
|
/* We don't implement transparent inserts */
|
|
if (flags == G_TF_TRANSPARENT)
|
|
return (NULL);
|
|
|
|
/*
|
|
* The BSD-method will not automatically configure itself recursively
|
|
* Note that it is legal to examine the class-name of our provider,
|
|
* nothing else should ever be examined inside the provider.
|
|
*/
|
|
if (flags == G_TF_NORMAL &&
|
|
!strcmp(pp->geom->class->name, BSD_CLASS_NAME))
|
|
return (NULL);
|
|
|
|
/*
|
|
* BSD labels are a subclass of the general "slicing" topology so
|
|
* a lot of the work can be done by the common "slice" code.
|
|
* Create a geom with space for MAXPARTITIONS providers, one consumer
|
|
* and a softc structure for us. Specify the provider to attach
|
|
* the consumer to and our "start" routine for special requests.
|
|
* The provider is opened with mode (1,0,0) so we can do reads
|
|
* from it.
|
|
*/
|
|
gp = g_slice_new(mp, MAXPARTITIONS, pp, &cp, &ms,
|
|
sizeof *ms, g_bsd_start);
|
|
if (gp == NULL)
|
|
return (NULL);
|
|
|
|
/*
|
|
* Now that we have attached to and opened our provider, we do
|
|
* not need the topology lock until we change the topology again
|
|
* next time.
|
|
*/
|
|
g_topology_unlock();
|
|
|
|
/*
|
|
* Fill in the optional details, in our case we have a dumpconf
|
|
* routine which the "slice" code should call at the right time
|
|
*/
|
|
gp->dumpconf = g_bsd_dumpconf;
|
|
|
|
/* Get the geom_slicer softc from the geom */
|
|
gsp = gp->softc;
|
|
|
|
/*
|
|
* The do...while loop here allows us to have multiple escapes
|
|
* using a simple "break". This improves code clarity without
|
|
* ending up in deep nesting and without using goto or come from.
|
|
*/
|
|
do {
|
|
/*
|
|
* If the provider is an MBR we will only auto attach
|
|
* to type 165 slices in the G_TF_NORMAL case. We will
|
|
* attach to any other type (BSD was handles above)
|
|
*/
|
|
error = g_getattr("MBR::type", cp, &i);
|
|
if (!error && i != 165 && flags == G_TF_NORMAL)
|
|
break;
|
|
|
|
/* Get sector size, we need it to read data. */
|
|
error = g_getattr("GEOM::sectorsize", cp, &secsize);
|
|
if (error || secsize < 512)
|
|
break;
|
|
|
|
/* First look for a label at the start of the second sector */
|
|
error = g_bsd_try(gsp, cp, secsize, ms, secsize);
|
|
|
|
/* Next, loot for it 64 bytes into the first sector */
|
|
if (error)
|
|
error = g_bsd_try(gsp, cp, secsize, ms, 64);
|
|
|
|
/* If we didn't find a label, punt */
|
|
if (error)
|
|
break;
|
|
|
|
/*
|
|
* Proccess the found disklabel, and modify our "slice"
|
|
* instance to match it, if possible.
|
|
*/
|
|
dl = &ms->inram;
|
|
error = g_bsd_modify(gp, dl); /* picks up topology lock */
|
|
if (!error)
|
|
g_topology_unlock();
|
|
break;
|
|
} while (0);
|
|
|
|
/* Success of failure, we can close our provider now */
|
|
g_topology_lock();
|
|
error = g_access_rel(cp, -1, 0, 0);
|
|
|
|
/* If we have configured any providers, return the new geom. */
|
|
if (gsp->nprovider > 0)
|
|
return (gp);
|
|
/*
|
|
* ...else push the "self-destruct" button, by spoiling our own
|
|
* consumer. This triggers a call to g_std_spoiled which will
|
|
* dismantle what was setup.
|
|
*/
|
|
g_std_spoiled(cp);
|
|
return (NULL);
|
|
}
|
|
|
|
/* Finally, register with GEOM infrastructure. */
|
|
static struct g_class g_bsd_class = {
|
|
BSD_CLASS_NAME,
|
|
g_bsd_taste,
|
|
NULL,
|
|
G_CLASS_INITIALIZER
|
|
};
|
|
|
|
DECLARE_GEOM_CLASS(g_bsd_class, g_bsd);
|