freebsd-skq/sys/geom/geom_slice.c
Poul-Henning Kamp 95c24b31df Make kernel dumps work with GEOM.
Notice that if the device on which the dump is set is destroyed for
any reason, the dump setting is lost.  This in particular will
happen in the case of spoilage.  For instance if you set dump on
ad0s1b and open ad0 for writing, ad0s* will be spoilt and the dump
setting lost.  See geom(4) for more about spoiling.

Sponsored by: DARPA & NAI Labs.
2002-04-19 09:24:12 +00:00

309 lines
8.5 KiB
C

/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* 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 <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <err.h>
#else
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#endif
#include <sys/errno.h>
#include <sys/sbuf.h>
#include <geom/geom.h>
#include <geom/geom_slice.h>
#include <machine/stdarg.h>
static g_orphan_t g_slice_orphan;
static g_access_t g_slice_access;
static g_start_t g_slice_start;
struct g_slicer *
g_slice_init(unsigned nslice, unsigned scsize)
{
struct g_slicer *gsp;
gsp = g_malloc(sizeof *gsp, M_WAITOK | M_ZERO);
gsp->softc = g_malloc(scsize, M_WAITOK | M_ZERO);
gsp->slices = g_malloc(nslice * sizeof(struct g_slice), M_WAITOK | M_ZERO);
gsp->nslice = nslice;
return (gsp);
}
static int
g_slice_access(struct g_provider *pp, int dr, int dw, int de)
{
int error, i;
struct g_geom *gp;
struct g_consumer *cp;
struct g_provider *pp2;
struct g_slicer *gsp;
struct g_slice *gsl, *gsl2;
gp = pp->geom;
cp = LIST_FIRST(&gp->consumer);
KASSERT (cp != NULL, ("g_slice_access but no consumer"));
gsp = gp->softc;
gsl = &gsp->slices[pp->index];
for (i = 0; i < gsp->nslice; i++) {
gsl2 = &gsp->slices[i];
if (gsl2->length == 0)
continue;
if (i == pp->index)
continue;
if (gsl->offset + gsl->length <= gsl2->offset)
continue;
if (gsl2->offset + gsl2->length <= gsl->offset)
continue;
/* overlap */
pp2 = gsl2->provider;
if ((pp->acw + dw) > 0 && pp2->ace > 0)
return (EPERM);
if ((pp->ace + de) > 0 && pp2->acw > 0)
return (EPERM);
}
/* On first open, grab an extra "exclusive" bit */
if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
de++;
/* ... and let go of it on last close */
if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1)
de--;
error = g_access_rel(cp, dr, dw, de);
pp->mediasize = gsp->slices[pp->index].length;
return (error);
}
static void
g_slice_start(struct bio *bp)
{
struct bio *bp2;
struct g_provider *pp;
struct g_geom *gp;
struct g_consumer *cp;
struct g_slicer *gsp;
struct g_slice *gsl;
int index;
off_t t;
pp = bp->bio_to;
gp = pp->geom;
gsp = gp->softc;
cp = LIST_FIRST(&gp->consumer);
index = pp->index;
gsl = &gsp->slices[index];
switch(bp->bio_cmd) {
case BIO_READ:
case BIO_WRITE:
case BIO_DELETE:
if (bp->bio_offset > gsl->length) {
bp->bio_error = EINVAL; /* XXX: EWHAT ? */
g_io_deliver(bp);
return;
}
bp2 = g_clone_bio(bp);
if (bp2->bio_offset + bp2->bio_length > gsl->length)
bp2->bio_length = gsl->length - bp2->bio_offset;
bp2->bio_done = g_std_done;
bp2->bio_offset += gsl->offset;
g_io_request(bp2, cp);
return;
case BIO_GETATTR:
case BIO_SETATTR:
/* Give the real method a chance to override */
if (gsp->start(bp))
return;
if (g_haveattr_off_t(bp, "GEOM::mediasize",
gsp->slices[index].length))
return;
if (!strcmp("GEOM::frontstuff", bp->bio_attribute)) {
t = gsp->cfrontstuff;
if (gsp->frontstuff > t)
t = gsp->frontstuff;
t -= gsl->offset;
if (t < 0)
t = 0;
if (t > gsl->length)
t = gsl->length;
g_haveattr_off_t(bp, "GEOM::frontstuff", t);
return;
}
if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) {
struct g_kerneldump *gkd;
gkd = (struct g_kerneldump *)bp->bio_data;
gkd->offset += gsp->slices[index].offset;
if (gkd->length > gsp->slices[index].length)
gkd->length = gsp->slices[index].length;
/* now, pass it on downwards... */
}
bp2 = g_clone_bio(bp);
bp2->bio_done = g_std_done;
g_io_request(bp2, cp);
break;
default:
bp->bio_error = EOPNOTSUPP;
g_io_deliver(bp);
return;
}
}
void
g_slice_dumpconf(struct sbuf *sb, char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
{
struct g_mbr_softc *mp;
struct g_slicer *gsp;
gsp = gp->softc;
mp = gsp->softc;
if (gp != NULL) {
sbuf_printf(sb, "%s<frontstuff>%llu</frontstuff>\n",
indent, (unsigned long long)gsp->frontstuff);
}
if (pp != NULL) {
sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
sbuf_printf(sb, "%s<length>%llu</length>\n",
indent, (unsigned long long)gsp->slices[pp->index].length);
sbuf_printf(sb, "%s<seclength>%llu</seclength>\n", indent,
(unsigned long long)gsp->slices[pp->index].length / 512);
sbuf_printf(sb, "%s<offset>%llu</offset>\n", indent,
(unsigned long long)gsp->slices[pp->index].offset);
sbuf_printf(sb, "%s<secoffset>%llu</secoffset>\n", indent,
(unsigned long long)gsp->slices[pp->index].offset / 512);
}
}
struct g_provider *
g_slice_addslice(struct g_geom *gp, int index, off_t offset, off_t length, char *fmt, ...)
{
struct g_provider *pp;
struct g_slicer *gsp;
va_list ap;
struct sbuf *sb;
g_trace(G_T_TOPOLOGY, "g_slice_addslice()");
g_topology_lock();
gsp = gp->softc;
va_start(ap, fmt);
sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
sbuf_vprintf(sb, fmt, ap);
sbuf_finish(sb);
pp = g_new_providerf(gp, sbuf_data(sb));
pp->index = index;
gsp->slices[index].length = length;
gsp->slices[index].offset = offset;
gsp->slices[index].provider = pp;
sbuf_delete(sb);
g_topology_unlock();
return(pp);
}
struct g_geom *
g_slice_new(struct g_class *mp, int slices, struct g_provider *pp, struct g_consumer **cpp, void *extrap, int extra, g_slice_start_t *start)
{
struct g_geom *gp;
struct g_slicer *gsp;
struct g_consumer *cp;
void **vp;
int error, i;
g_topology_assert();
vp = (void **)extrap;
gp = g_new_geomf(mp, "%s", pp->name);
gsp = g_slice_init(slices, extra);
gsp->start = start;
gp->access = g_slice_access;
gp->orphan = g_slice_orphan;
gp->softc = gsp;
gp->start = g_slice_start;
gp->spoiled = g_std_spoiled;
gp->dumpconf = g_slice_dumpconf;
cp = g_new_consumer(gp);
g_attach(cp, pp);
error = g_access_rel(cp, 1, 0, 0);
if (error) {
g_dettach(cp);
g_destroy_consumer(cp);
g_free(gsp->slices);
g_free(gp->softc);
g_destroy_geom(gp);
return (NULL);
}
/* Find out if there are any magic bytes on the consumer */
i = sizeof gsp->cfrontstuff;
error = g_io_getattr("GEOM::frontstuff", cp, &i, &gsp->cfrontstuff);
if (error)
gsp->cfrontstuff = 0;
*vp = gsp->softc;
*cpp = cp;
return (gp);
}
static void
g_slice_orphan(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_provider *pp;
int error;
g_trace(G_T_TOPOLOGY, "g_slice_orphan(%p/%s)", cp, cp->provider->name);
g_topology_assert();
KASSERT(cp->provider->error != 0,
("g_slice_orphan with error == 0"));
gp = cp->geom;
gp->flags |= G_GEOM_WITHER;
/* First prevent any new requests */
error = cp->provider->error;
LIST_FOREACH(pp, &gp->provider, provider)
g_orphan_provider(pp, error);
return;
}