freebsd-dev/sys/geom/geom_gpt.c
Poul-Henning Kamp 3f12caa180 Now that the sectorsize and mediasize are properties of the provider,
don't take the detour over the I/O path to discover them using getattr(),
we can just pick them out directly.

Do note though, that for now they are only valid after the first open
of the underlying disk device due compatibility with the old disk_create()
API.  This will change in the future so they will always be valid.

Sponsored by:   DARPA & NAI Labs.
2002-10-20 20:28:24 +00:00

262 lines
7.1 KiB
C

/*-
* Copyright (c) 2002 Marcel Moolenaar
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, 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.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#ifndef _KERNEL
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <sys/param.h>
#include <stdlib.h>
#include <err.h>
#else
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#endif
#include <sys/endian.h>
#include <sys/sbuf.h>
#include <sys/uuid.h>
#include <sys/gpt.h>
#include <geom/geom.h>
#include <geom/geom_slice.h>
CTASSERT(offsetof(struct gpt_hdr, padding) == 92);
CTASSERT(sizeof(struct gpt_ent) == 128);
/*
* XXX: GEOM is not dynamic enough. We are forced to use a compile-time
* limit. The minimum number of partitions (128) as required by EFI is
* most of the time just a waste of space.
*/
#define GPT_MAX_SLICES 128
struct g_gpt_softc {
struct gpt_ent *part[GPT_MAX_SLICES];
};
static int
is_gpt_hdr(struct gpt_hdr *hdr)
{
uint32_t crc;
if (memcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)))
return (0);
crc = hdr->hdr_crc_self;
hdr->hdr_crc_self = 0;
if (crc32(hdr, hdr->hdr_size) != crc)
return (0);
hdr->hdr_crc_self = crc;
/* We're happy... */
return (1);
}
static int
g_gpt_start(struct bio *bp)
{
struct uuid freebsd = GPT_ENT_TYPE_FREEBSD;
struct g_provider *pp = bp->bio_to;
struct g_geom *gp = pp->geom;
struct g_slicer *gsp = gp->softc;
struct g_gpt_softc *gs = gsp->softc;
u_int type;
if (bp->bio_cmd != BIO_GETATTR)
return (0);
/*
* XXX: this is bogus. The BSD class has a strong dependency on
* the MBR/MBREXT class, because it asks for an attribute that's
* specific to the MBR/MBREXT class and the value of the attribute
* is just as specific to the MBR class. In an extensible scheme
* a geom would ask another geom if it could possible accomodate a
* class and the answer should be yes or no. Now we're forced to
* emulate a MBR class :-/
*/
type = (memcmp(&gs->part[pp->index]->ent_type, &freebsd,
sizeof(freebsd))) ? 0 : 165;
return ((g_handleattr_int(bp, "MBR::type", type)) ? 1 : 0);
}
static void
g_gpt_dumpconf(struct sbuf *sb, char *indent, struct g_geom *gp,
struct g_consumer *cp, struct g_provider *pp)
{
struct g_slicer *gsp = gp->softc;
struct g_gpt_softc *gs = gsp->softc;
struct uuid *uuid;
g_slice_dumpconf(sb, indent, gp, cp, pp);
if (pp != NULL) {
uuid = &gs->part[pp->index]->ent_type;
sbuf_printf(sb, "%s<type>", indent);
sbuf_printf_uuid(sb, uuid);
sbuf_printf(sb, "</type>\n");
}
}
static struct g_geom *
g_gpt_taste(struct g_class *mp, struct g_provider *pp, int insist)
{
struct g_consumer *cp;
struct g_geom *gp;
struct g_gpt_softc *gs;
struct g_slicer *gsp;
u_char *buf, *mbr;
struct gpt_ent *ent;
struct gpt_hdr *hdr;
u_int i, npart, secsz, tblsz;
int error, ps;
g_trace(G_T_TOPOLOGY, "g_gpt_taste(%s,%s)", mp->name, pp->name);
g_topology_assert();
/*
* XXX: I don't like to hardcode a maximum number of slices, since
* it's wasting space most of the time and insufficient any time.
* It's easier for now...
*/
gp = g_slice_new(mp, GPT_MAX_SLICES, pp, &cp, &gs, sizeof(*gs),
g_gpt_start);
if (gp == NULL)
return (NULL);
gsp = gp->softc;
g_topology_unlock();
gp->dumpconf = g_gpt_dumpconf;
do {
npart = 0;
mbr = NULL;
if (gp->rank != 2 && insist == 0)
break;
secsz = cp->provider->sectorsize;
if (secsz < 512)
break;
/* XXX: we need to get the media size as well. */
/* Read both the MBR sector and the GPT sector. */
mbr = g_read_data(cp, 0, 2 * secsz, &error);
if (mbr == NULL || error != 0)
break;
#if 0
/*
* XXX: we should ignore the GPT if there's a MBR and the MBR is
* not a PMBR (Protective MBR). I believe this is what the EFI
* spec is going to say eventually (this is hearsay :-)
* Currently EFI (version 1.02) accepts and uses the GPT even
* though there's a valid MBR. We do this too, because it allows
* us to test this code without first nuking the only partitioning
* scheme we grok until this is working.
*/
if (!is_pmbr((void*)mbr))
goto out;
#endif
hdr = (void*)(mbr + secsz);
/*
* XXX: if we don't have a GPT header at LBA 1, we should check if
* there's a backup GPT at the end of the medium. If we have a valid
* backup GPT, we should restore the primary GPT and claim this lunch.
*/
if (!is_gpt_hdr(hdr))
break;
tblsz = (hdr->hdr_entries * hdr->hdr_entsz + secsz - 1) &
~(secsz - 1);
buf = g_read_data(cp, hdr->hdr_lba_table * secsz, tblsz, &error);
gsp->frontstuff = hdr->hdr_lba_start * secsz;
for (i = 0; i < hdr->hdr_entries; i++) {
struct uuid unused = GPT_ENT_TYPE_UNUSED;
struct uuid freebsd = GPT_ENT_TYPE_FREEBSD;
if (i >= GPT_MAX_SLICES)
break;
ent = (void*)(buf + i * hdr->hdr_entsz);
if (!memcmp(&ent->ent_type, &unused, sizeof(unused)))
continue;
gs->part[i] = g_malloc(hdr->hdr_entsz, M_WAITOK);
if (gs->part[i] == NULL)
break;
bcopy(ent, gs->part[i], hdr->hdr_entsz);
ps = (!memcmp(&ent->ent_type, &freebsd, sizeof(freebsd)))
? 's' : 'p';
g_topology_lock();
(void)g_slice_addslice(gp, i,
ent->ent_lba_start * secsz,
(1 + ent->ent_lba_end - ent->ent_lba_start) * secsz,
secsz,
"%s%c%d", gp->name, ps, i + 1);
g_topology_unlock();
npart++;
}
g_free(buf);
} while (0);
if (mbr != NULL)
g_free(mbr);
g_topology_lock();
error = g_access_rel(cp, -1, 0, 0);
if (npart > 0) {
LIST_FOREACH(pp, &gp->provider, provider)
g_error_provider(pp, 0);
return (gp);
}
g_std_spoiled(cp);
return (NULL);
}
static struct g_class g_gpt_class = {
"GPT",
g_gpt_taste,
NULL,
G_CLASS_INITIALIZER
};
DECLARE_GEOM_CLASS(g_gpt_class, g_gpt);