geom_slice.c revision 96952
1/*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7 * and NAI Labs, the Security Research Division of Network Associates, Inc. 8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9 * DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The names of the authors may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * $FreeBSD: head/sys/geom/geom_slice.c 96952 2002-05-19 18:59:39Z phk $ 36 */ 37 38 39#include <sys/param.h> 40#ifndef _KERNEL 41#include <stdio.h> 42#include <unistd.h> 43#include <stdlib.h> 44#include <signal.h> 45#include <string.h> 46#include <err.h> 47#else 48#include <sys/systm.h> 49#include <sys/kernel.h> 50#include <sys/malloc.h> 51#include <sys/bio.h> 52#include <sys/sysctl.h> 53#include <sys/proc.h> 54#include <sys/kthread.h> 55#include <sys/lock.h> 56#include <sys/mutex.h> 57#endif 58#include <sys/errno.h> 59#include <sys/sbuf.h> 60#include <geom/geom.h> 61#include <geom/geom_slice.h> 62#include <machine/stdarg.h> 63 64static g_orphan_t g_slice_orphan; 65static g_access_t g_slice_access; 66static g_start_t g_slice_start; 67 68static struct g_slicer * 69g_slice_init(unsigned nslice, unsigned scsize) 70{ 71 struct g_slicer *gsp; 72 73 gsp = g_malloc(sizeof *gsp, M_WAITOK | M_ZERO); 74 gsp->softc = g_malloc(scsize, M_WAITOK | M_ZERO); 75 gsp->slices = g_malloc(nslice * sizeof(struct g_slice), M_WAITOK | M_ZERO); 76 gsp->nslice = nslice; 77 return (gsp); 78} 79 80static int 81g_slice_access(struct g_provider *pp, int dr, int dw, int de) 82{ 83 int error, i; 84 struct g_geom *gp; 85 struct g_consumer *cp; 86 struct g_provider *pp2; 87 struct g_slicer *gsp; 88 struct g_slice *gsl, *gsl2; 89 90 gp = pp->geom; 91 cp = LIST_FIRST(&gp->consumer); 92 KASSERT (cp != NULL, ("g_slice_access but no consumer")); 93 gsp = gp->softc; 94 gsl = &gsp->slices[pp->index]; 95 for (i = 0; i < gsp->nslice; i++) { 96 gsl2 = &gsp->slices[i]; 97 if (gsl2->length == 0) 98 continue; 99 if (i == pp->index) 100 continue; 101 if (gsl->offset + gsl->length <= gsl2->offset) 102 continue; 103 if (gsl2->offset + gsl2->length <= gsl->offset) 104 continue; 105 /* overlap */ 106 pp2 = gsl2->provider; 107 if ((pp->acw + dw) > 0 && pp2->ace > 0) 108 return (EPERM); 109 if ((pp->ace + de) > 0 && pp2->acw > 0) 110 return (EPERM); 111 } 112 /* On first open, grab an extra "exclusive" bit */ 113 if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0) 114 de++; 115 /* ... and let go of it on last close */ 116 if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1) 117 de--; 118 error = g_access_rel(cp, dr, dw, de); 119 pp->mediasize = gsp->slices[pp->index].length; 120 return (error); 121} 122 123static void 124g_slice_start(struct bio *bp) 125{ 126 struct bio *bp2; 127 struct g_provider *pp; 128 struct g_geom *gp; 129 struct g_consumer *cp; 130 struct g_slicer *gsp; 131 struct g_slice *gsl; 132 int index; 133 off_t t; 134 135 pp = bp->bio_to; 136 gp = pp->geom; 137 gsp = gp->softc; 138 cp = LIST_FIRST(&gp->consumer); 139 index = pp->index; 140 gsl = &gsp->slices[index]; 141 switch(bp->bio_cmd) { 142 case BIO_READ: 143 case BIO_WRITE: 144 case BIO_DELETE: 145 if (bp->bio_offset > gsl->length) { 146 bp->bio_error = EINVAL; /* XXX: EWHAT ? */ 147 g_io_deliver(bp); 148 return; 149 } 150 bp2 = g_clone_bio(bp); 151 if (bp2->bio_offset + bp2->bio_length > gsl->length) 152 bp2->bio_length = gsl->length - bp2->bio_offset; 153 bp2->bio_done = g_std_done; 154 bp2->bio_offset += gsl->offset; 155 g_io_request(bp2, cp); 156 return; 157 case BIO_GETATTR: 158 case BIO_SETATTR: 159 /* Give the real method a chance to override */ 160 if (gsp->start(bp)) 161 return; 162 if (g_haveattr_off_t(bp, "GEOM::mediasize", 163 gsp->slices[index].length)) 164 return; 165 if (!strcmp("GEOM::frontstuff", bp->bio_attribute)) { 166 t = gsp->cfrontstuff; 167 if (gsp->frontstuff > t) 168 t = gsp->frontstuff; 169 t -= gsl->offset; 170 if (t < 0) 171 t = 0; 172 if (t > gsl->length) 173 t = gsl->length; 174 g_haveattr_off_t(bp, "GEOM::frontstuff", t); 175 return; 176 } 177#ifdef _KERNEL 178 if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) { 179 struct g_kerneldump *gkd; 180 181 gkd = (struct g_kerneldump *)bp->bio_data; 182 gkd->offset += gsp->slices[index].offset; 183 if (gkd->length > gsp->slices[index].length) 184 gkd->length = gsp->slices[index].length; 185 /* now, pass it on downwards... */ 186 } 187#endif 188 bp2 = g_clone_bio(bp); 189 bp2->bio_done = g_std_done; 190 g_io_request(bp2, cp); 191 break; 192 default: 193 bp->bio_error = EOPNOTSUPP; 194 g_io_deliver(bp); 195 return; 196 } 197} 198 199void 200g_slice_dumpconf(struct sbuf *sb, char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp) 201{ 202 struct g_mbr_softc *mp; 203 struct g_slicer *gsp; 204 205 gsp = gp->softc; 206 mp = gsp->softc; 207 if (gp != NULL && (pp == NULL && cp == NULL)) { 208 sbuf_printf(sb, "%s<frontstuff>%llu</frontstuff>\n", 209 indent, (unsigned long long)gsp->frontstuff); 210 } 211 if (pp != NULL) { 212 sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index); 213 sbuf_printf(sb, "%s<length>%llu</length>\n", 214 indent, (unsigned long long)gsp->slices[pp->index].length); 215 sbuf_printf(sb, "%s<seclength>%llu</seclength>\n", indent, 216 (unsigned long long)gsp->slices[pp->index].length / 512); 217 sbuf_printf(sb, "%s<offset>%llu</offset>\n", indent, 218 (unsigned long long)gsp->slices[pp->index].offset); 219 sbuf_printf(sb, "%s<secoffset>%llu</secoffset>\n", indent, 220 (unsigned long long)gsp->slices[pp->index].offset / 512); 221 } 222} 223 224struct g_provider * 225g_slice_addslice(struct g_geom *gp, int index, off_t offset, off_t length, char *fmt, ...) 226{ 227 struct g_provider *pp; 228 struct g_slicer *gsp; 229 va_list ap; 230 struct sbuf *sb; 231 232 g_trace(G_T_TOPOLOGY, "g_slice_addslice()"); 233 g_topology_lock(); 234 gsp = gp->softc; 235 va_start(ap, fmt); 236 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 237 sbuf_vprintf(sb, fmt, ap); 238 sbuf_finish(sb); 239 pp = g_new_providerf(gp, sbuf_data(sb)); 240 241 pp->index = index; 242 gsp->slices[index].length = length; 243 gsp->slices[index].offset = offset; 244 gsp->slices[index].provider = pp; 245 sbuf_delete(sb); 246 g_topology_unlock(); 247 return(pp); 248} 249 250struct g_geom * 251g_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) 252{ 253 struct g_geom *gp; 254 struct g_slicer *gsp; 255 struct g_consumer *cp; 256 void **vp; 257 int error, i; 258 259 g_topology_assert(); 260 vp = (void **)extrap; 261 gp = g_new_geomf(mp, "%s", pp->name); 262 gsp = g_slice_init(slices, extra); 263 gsp->start = start; 264 gp->access = g_slice_access; 265 gp->orphan = g_slice_orphan; 266 gp->softc = gsp; 267 gp->start = g_slice_start; 268 gp->spoiled = g_std_spoiled; 269 gp->dumpconf = g_slice_dumpconf; 270 cp = g_new_consumer(gp); 271 g_attach(cp, pp); 272 error = g_access_rel(cp, 1, 0, 0); 273 if (error) { 274 g_dettach(cp); 275 g_destroy_consumer(cp); 276 g_free(gsp->slices); 277 g_free(gp->softc); 278 g_destroy_geom(gp); 279 return (NULL); 280 } 281 /* Find out if there are any magic bytes on the consumer */ 282 i = sizeof gsp->cfrontstuff; 283 error = g_io_getattr("GEOM::frontstuff", cp, &i, &gsp->cfrontstuff); 284 if (error) 285 gsp->cfrontstuff = 0; 286 *vp = gsp->softc; 287 *cpp = cp; 288 return (gp); 289} 290 291static void 292g_slice_orphan(struct g_consumer *cp) 293{ 294 struct g_geom *gp; 295 struct g_provider *pp; 296 int error; 297 298 g_trace(G_T_TOPOLOGY, "g_slice_orphan(%p/%s)", cp, cp->provider->name); 299 g_topology_assert(); 300 KASSERT(cp->provider->error != 0, 301 ("g_slice_orphan with error == 0")); 302 303 gp = cp->geom; 304 gp->flags |= G_GEOM_WITHER; 305 error = cp->provider->error; 306 LIST_FOREACH(pp, &gp->provider, provider) 307 g_orphan_provider(pp, error); 308 return; 309} 310