freebsd-dev/sys/geom/geom_slice.c

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/*-
* 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 <string.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;
static 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_handleattr_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_handleattr_off_t(bp, "GEOM::frontstuff", t);
return;
}
#ifdef _KERNEL
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... */
}
#endif
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 && (pp == NULL && cp == 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_detach(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;
error = cp->provider->error;
LIST_FOREACH(pp, &gp->provider, provider)
g_orphan_provider(pp, error);
return;
}