The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_subr.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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 
   36 #include <sys/cdefs.h>
   37 __FBSDID("$FreeBSD: releng/5.2/sys/geom/geom_subr.c 122888 2003-11-18 18:17:39Z phk $");
   38 
   39 #include <sys/param.h>
   40 #include <sys/systm.h>
   41 #include <sys/devicestat.h>
   42 #include <sys/kernel.h>
   43 #include <sys/malloc.h>
   44 #include <sys/bio.h>
   45 #include <sys/sysctl.h>
   46 #include <sys/proc.h>
   47 #include <sys/kthread.h>
   48 #include <sys/lock.h>
   49 #include <sys/mutex.h>
   50 #include <sys/errno.h>
   51 #include <sys/sbuf.h>
   52 #include <geom/geom.h>
   53 #include <geom/geom_int.h>
   54 #include <machine/stdarg.h>
   55 
   56 struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
   57 static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
   58 char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
   59 
   60 static int g_valid_obj(void const *ptr);
   61 
   62 struct g_hh00 {
   63         struct g_class  *mp;
   64         int             error;
   65 };
   66 
   67 /*
   68  * This event offers a new class a chance to taste all preexisting providers.
   69  */
   70 static void
   71 g_load_class(void *arg, int flag)
   72 {
   73         struct g_hh00 *hh;
   74         struct g_class *mp2, *mp;
   75         struct g_geom *gp;
   76         struct g_provider *pp;
   77 
   78         g_topology_assert();
   79         if (flag == EV_CANCEL)  /* XXX: can't happen ? */
   80                 return;
   81         if (g_shutdown)
   82                 return;
   83 
   84         hh = arg;
   85         mp = hh->mp;
   86         g_free(hh);
   87         g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
   88         LIST_FOREACH(mp2, &g_classes, class) {
   89                 KASSERT(mp2 != mp,
   90                     ("The GEOM class %s already loaded", mp2->name));
   91                 KASSERT(strcmp(mp2->name, mp->name) != 0,
   92                     ("A GEOM class named %s is already loaded", mp2->name));
   93         }
   94 
   95         LIST_INIT(&mp->geom);
   96         LIST_INSERT_HEAD(&g_classes, mp, class);
   97         if (mp->init != NULL)
   98                 mp->init(mp);
   99         if (mp->taste == NULL)
  100                 return;
  101         LIST_FOREACH(mp2, &g_classes, class) {
  102                 if (mp == mp2)
  103                         continue;
  104                 LIST_FOREACH(gp, &mp2->geom, geom) {
  105                         LIST_FOREACH(pp, &gp->provider, provider) {
  106                                 mp->taste(mp, pp, 0);
  107                                 g_topology_assert();
  108                         }
  109                 }
  110         }
  111 }
  112 
  113 static void
  114 g_unload_class(void *arg, int flag)
  115 {
  116         struct g_hh00 *hh;
  117         struct g_class *mp;
  118         struct g_geom *gp;
  119         struct g_provider *pp;
  120         struct g_consumer *cp;
  121         int error;
  122 
  123         g_topology_assert();
  124         hh = arg;
  125         mp = hh->mp;
  126         g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
  127         if (mp->destroy_geom == NULL) {
  128                 hh->error = EOPNOTSUPP;
  129                 return;
  130         }
  131 
  132         /* We refuse to unload if anything is open */
  133         LIST_FOREACH(gp, &mp->geom, geom) {
  134                 LIST_FOREACH(pp, &gp->provider, provider)
  135                         if (pp->acr || pp->acw || pp->ace) {
  136                                 hh->error = EBUSY;
  137                                 return;
  138                         }
  139                 LIST_FOREACH(cp, &gp->consumer, consumer)
  140                         if (cp->acr || cp->acw || cp->ace) {
  141                                 hh->error = EBUSY;
  142                                 return;
  143                         }
  144         }
  145 
  146         /* Bar new entries */
  147         mp->taste = NULL;
  148         mp->config = NULL;
  149 
  150         error = 0;
  151         LIST_FOREACH(gp, &mp->geom, geom) {
  152                 error = mp->destroy_geom(NULL, mp, gp);
  153                 if (error != 0)
  154                         break;
  155         }
  156         if (error == 0) {
  157                 if (mp->fini != NULL)
  158                         mp->fini(mp);
  159                 LIST_REMOVE(mp, class);
  160         }
  161         hh->error = error;
  162         return;
  163 }
  164 
  165 int
  166 g_modevent(module_t mod, int type, void *data)
  167 {
  168         struct g_hh00 *hh;
  169         int error;
  170         static int g_ignition;
  171 
  172         if (!g_ignition) {
  173                 g_ignition++;
  174                 g_init();
  175         }
  176         hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
  177         hh->mp = data;
  178         error = EOPNOTSUPP;
  179         switch (type) {
  180         case MOD_LOAD:
  181                 g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name);
  182                 g_post_event(g_load_class, hh, M_WAITOK, NULL);
  183                 error = 0;
  184                 break;
  185         case MOD_UNLOAD:
  186                 g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name);
  187                 error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL);
  188                 if (error == 0)
  189                         error = hh->error;
  190                 if (error == 0) {
  191                         g_waitidle();
  192                         KASSERT(LIST_EMPTY(&hh->mp->geom),
  193                             ("Unloaded class (%s) still has geom", hh->mp->name));
  194                 }
  195                 g_free(hh);
  196                 break;
  197         }
  198         return (error);
  199 }
  200 
  201 struct g_geom *
  202 g_new_geomf(struct g_class *mp, const char *fmt, ...)
  203 {
  204         struct g_geom *gp;
  205         va_list ap;
  206         struct sbuf *sb;
  207 
  208         g_topology_assert();
  209         KASSERT(g_valid_obj(mp), ("g_new_geom_f() on alien class %p", mp));
  210         sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
  211         va_start(ap, fmt);
  212         sbuf_vprintf(sb, fmt, ap);
  213         va_end(ap);
  214         sbuf_finish(sb);
  215         gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
  216         gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
  217         gp->class = mp;
  218         gp->rank = 1;
  219         LIST_INIT(&gp->consumer);
  220         LIST_INIT(&gp->provider);
  221         LIST_INSERT_HEAD(&mp->geom, gp, geom);
  222         TAILQ_INSERT_HEAD(&geoms, gp, geoms);
  223         strcpy(gp->name, sbuf_data(sb));
  224         sbuf_delete(sb);
  225         return (gp);
  226 }
  227 
  228 void
  229 g_destroy_geom(struct g_geom *gp)
  230 {
  231 
  232         g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
  233         g_topology_assert();
  234         KASSERT(LIST_EMPTY(&gp->consumer),
  235             ("g_destroy_geom(%s) with consumer(s) [%p]",
  236             gp->name, LIST_FIRST(&gp->consumer)));
  237         KASSERT(LIST_EMPTY(&gp->provider),
  238             ("g_destroy_geom(%s) with provider(s) [%p]",
  239             gp->name, LIST_FIRST(&gp->consumer)));
  240         g_cancel_event(gp);
  241         LIST_REMOVE(gp, geom);
  242         TAILQ_REMOVE(&geoms, gp, geoms);
  243         g_free(gp->name);
  244         g_free(gp);
  245 }
  246 
  247 /*
  248  * This function is called (repeatedly) until has withered away.
  249  */
  250 void
  251 g_wither_geom(struct g_geom *gp, int error)
  252 {
  253         struct g_provider *pp, *pp2;
  254         struct g_consumer *cp, *cp2;
  255         static int once_is_enough;
  256 
  257         if (once_is_enough)
  258                 return;
  259         once_is_enough = 1;
  260         g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
  261         g_topology_assert();
  262         if (!(gp->flags & G_GEOM_WITHER)) {
  263                 gp->flags |= G_GEOM_WITHER;
  264                 LIST_FOREACH(pp, &gp->provider, provider)
  265                         g_orphan_provider(pp, error);
  266         }
  267         for (pp = LIST_FIRST(&gp->provider); pp != NULL; pp = pp2) {
  268                 pp2 = LIST_NEXT(pp, provider);
  269                 if (!LIST_EMPTY(&pp->consumers))
  270                         continue;
  271                 g_destroy_provider(pp);
  272         }
  273         for (cp = LIST_FIRST(&gp->consumer); cp != NULL; cp = cp2) {
  274                 cp2 = LIST_NEXT(cp, consumer);
  275                 if (cp->acr || cp->acw || cp->ace)
  276                         continue;
  277                 g_detach(cp);
  278                 g_destroy_consumer(cp);
  279         }
  280         if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
  281                 g_destroy_geom(gp);
  282         once_is_enough = 0;
  283 }
  284 
  285 struct g_consumer *
  286 g_new_consumer(struct g_geom *gp)
  287 {
  288         struct g_consumer *cp;
  289 
  290         g_topology_assert();
  291         KASSERT(gp->orphan != NULL,
  292             ("g_new_consumer on geom(%s) (class %s) without orphan",
  293             gp->name, gp->class->name));
  294 
  295         cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
  296         cp->geom = gp;
  297         cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
  298             DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
  299         LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
  300         return(cp);
  301 }
  302 
  303 void
  304 g_destroy_consumer(struct g_consumer *cp)
  305 {
  306         struct g_geom *gp;
  307 
  308         g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
  309         g_topology_assert();
  310         KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
  311         KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
  312         KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
  313         KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
  314         g_cancel_event(cp);
  315         gp = cp->geom;
  316         LIST_REMOVE(cp, consumer);
  317         devstat_remove_entry(cp->stat);
  318         g_free(cp);
  319         if (gp->flags & G_GEOM_WITHER)
  320                 g_wither_geom(gp, 0);
  321 }
  322 
  323 static void
  324 g_new_provider_event(void *arg, int flag)
  325 {
  326         struct g_class *mp;
  327         struct g_provider *pp;
  328         struct g_consumer *cp;
  329         int i;
  330 
  331         g_topology_assert();
  332         if (flag == EV_CANCEL)
  333                 return;
  334         if (g_shutdown)
  335                 return;
  336         pp = arg;
  337         LIST_FOREACH(mp, &g_classes, class) {
  338                 if (mp->taste == NULL)
  339                         continue;
  340                 i = 1;
  341                 LIST_FOREACH(cp, &pp->consumers, consumers)
  342                         if (cp->geom->class == mp)
  343                                 i = 0;
  344                 if (!i)
  345                         continue;
  346                 mp->taste(mp, pp, 0);
  347                 g_topology_assert();
  348                 /*
  349                  * XXX: Bandaid for 5.2-RELEASE
  350                  * XXX: DO NOT REPLICATE THIS CODE!
  351                  */
  352                 if (!g_valid_obj(pp)) {
  353                         printf("g_provider %p disappeared while tasting\n", pp);
  354                         return;
  355                 }
  356         }
  357 }
  358 
  359 
  360 struct g_provider *
  361 g_new_providerf(struct g_geom *gp, const char *fmt, ...)
  362 {
  363         struct g_provider *pp;
  364         struct sbuf *sb;
  365         va_list ap;
  366 
  367         g_topology_assert();
  368         sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
  369         va_start(ap, fmt);
  370         sbuf_vprintf(sb, fmt, ap);
  371         va_end(ap);
  372         sbuf_finish(sb);
  373         pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
  374         pp->name = (char *)(pp + 1);
  375         strcpy(pp->name, sbuf_data(sb));
  376         sbuf_delete(sb);
  377         LIST_INIT(&pp->consumers);
  378         pp->error = ENXIO;
  379         pp->geom = gp;
  380         pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
  381             DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
  382         LIST_INSERT_HEAD(&gp->provider, pp, provider);
  383         g_post_event(g_new_provider_event, pp, M_WAITOK, pp, NULL);
  384         return (pp);
  385 }
  386 
  387 void
  388 g_error_provider(struct g_provider *pp, int error)
  389 {
  390 
  391         pp->error = error;
  392 }
  393 
  394 struct g_provider *
  395 g_provider_by_name(char const *arg)
  396 {
  397         struct g_class *cp;
  398         struct g_geom *gp;
  399         struct g_provider *pp;
  400 
  401         LIST_FOREACH(cp, &g_classes, class) {
  402                 LIST_FOREACH(gp, &cp->geom, geom) {
  403                         LIST_FOREACH(pp, &gp->provider, provider) {
  404                                 if (!strcmp(arg, pp->name))
  405                                         return (pp);
  406                         }
  407                 }
  408         }
  409         return (NULL);
  410 }
  411 
  412 void
  413 g_destroy_provider(struct g_provider *pp)
  414 {
  415         struct g_geom *gp;
  416 
  417         g_topology_assert();
  418         KASSERT(LIST_EMPTY(&pp->consumers),
  419             ("g_destroy_provider but attached"));
  420         KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
  421         KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
  422         KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
  423         g_cancel_event(pp);
  424         LIST_REMOVE(pp, provider);
  425         gp = pp->geom;
  426         devstat_remove_entry(pp->stat);
  427         g_free(pp);
  428         if ((gp->flags & G_GEOM_WITHER))
  429                 g_wither_geom(gp, 0);
  430 }
  431 
  432 /*
  433  * We keep the "geoms" list sorted by topological order (== increasing
  434  * numerical rank) at all times.
  435  * When an attach is done, the attaching geoms rank is invalidated
  436  * and it is moved to the tail of the list.
  437  * All geoms later in the sequence has their ranks reevaluated in
  438  * sequence.  If we cannot assign rank to a geom because it's
  439  * prerequisites do not have rank, we move that element to the tail
  440  * of the sequence with invalid rank as well.
  441  * At some point we encounter our original geom and if we stil fail
  442  * to assign it a rank, there must be a loop and we fail back to
  443  * g_attach() which detach again and calls redo_rank again
  444  * to fix up the damage.
  445  * It would be much simpler code wise to do it recursively, but we
  446  * can't risk that on the kernel stack.
  447  */
  448 
  449 static int
  450 redo_rank(struct g_geom *gp)
  451 {
  452         struct g_consumer *cp;
  453         struct g_geom *gp1, *gp2;
  454         int n, m;
  455 
  456         g_topology_assert();
  457 
  458         /* Invalidate this geoms rank and move it to the tail */
  459         gp1 = TAILQ_NEXT(gp, geoms);
  460         if (gp1 != NULL) {
  461                 gp->rank = 0;
  462                 TAILQ_REMOVE(&geoms, gp, geoms);
  463                 TAILQ_INSERT_TAIL(&geoms, gp, geoms);
  464         } else {
  465                 gp1 = gp;
  466         }
  467 
  468         /* re-rank the rest of the sequence */
  469         for (; gp1 != NULL; gp1 = gp2) {
  470                 gp1->rank = 0;
  471                 m = 1;
  472                 LIST_FOREACH(cp, &gp1->consumer, consumer) {
  473                         if (cp->provider == NULL)
  474                                 continue;
  475                         n = cp->provider->geom->rank;
  476                         if (n == 0) {
  477                                 m = 0;
  478                                 break;
  479                         } else if (n >= m)
  480                                 m = n + 1;
  481                 }
  482                 gp1->rank = m;
  483                 gp2 = TAILQ_NEXT(gp1, geoms);
  484 
  485                 /* got a rank, moving on */
  486                 if (m != 0)
  487                         continue;
  488 
  489                 /* no rank to original geom means loop */
  490                 if (gp == gp1) 
  491                         return (ELOOP);
  492 
  493                 /* no rank, put it at the end move on */
  494                 TAILQ_REMOVE(&geoms, gp1, geoms);
  495                 TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
  496         }
  497         return (0);
  498 }
  499 
  500 int
  501 g_attach(struct g_consumer *cp, struct g_provider *pp)
  502 {
  503         int error;
  504 
  505         g_topology_assert();
  506         KASSERT(cp->provider == NULL, ("attach but attached"));
  507         cp->provider = pp;
  508         LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
  509         error = redo_rank(cp->geom);
  510         if (error) {
  511                 LIST_REMOVE(cp, consumers);
  512                 cp->provider = NULL;
  513                 redo_rank(cp->geom);
  514         }
  515         return (error);
  516 }
  517 
  518 void
  519 g_detach(struct g_consumer *cp)
  520 {
  521         struct g_provider *pp;
  522 
  523         g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
  524         KASSERT(cp != (void*)0xd0d0d0d0, ("ARGH!"));
  525         g_topology_assert();
  526         KASSERT(cp->provider != NULL, ("detach but not attached"));
  527         KASSERT(cp->acr == 0, ("detach but nonzero acr"));
  528         KASSERT(cp->acw == 0, ("detach but nonzero acw"));
  529         KASSERT(cp->ace == 0, ("detach but nonzero ace"));
  530         KASSERT(cp->nstart == cp->nend,
  531             ("detach with active requests"));
  532         pp = cp->provider;
  533         LIST_REMOVE(cp, consumers);
  534         cp->provider = NULL;
  535         if (pp->geom->flags & G_GEOM_WITHER)
  536                 g_wither_geom(pp->geom, 0);
  537         else if (pp->flags & G_PF_WITHER)
  538                 g_destroy_provider(pp);
  539         redo_rank(cp->geom);
  540 }
  541 
  542 
  543 /*
  544  * g_access_abs()
  545  *
  546  * Access-check with absolute new values:  Just fall through
  547  * and use the relative version.
  548  */
  549 int
  550 g_access_abs(struct g_consumer *cp, int acr, int acw, int ace)
  551 {
  552 
  553         g_topology_assert();
  554         return(g_access_rel(cp,
  555                 acr - cp->acr,
  556                 acw - cp->acw,
  557                 ace - cp->ace));
  558 }
  559 
  560 /*
  561  * g_access_rel()
  562  *
  563  * Access-check with delta values.  The question asked is "can provider
  564  * "cp" change the access counters by the relative amounts dc[rwe] ?"
  565  */
  566 
  567 int
  568 g_access_rel(struct g_consumer *cp, int dcr, int dcw, int dce)
  569 {
  570         struct g_provider *pp;
  571         int pr,pw,pe;
  572         int error;
  573 
  574         pp = cp->provider;
  575 
  576         g_trace(G_T_ACCESS, "g_access_rel(%p(%s), %d, %d, %d)",
  577             cp, pp->name, dcr, dcw, dce);
  578 
  579         g_topology_assert();
  580         KASSERT(cp->provider != NULL, ("access but not attached"));
  581         KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
  582         KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
  583         KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
  584         KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
  585 
  586         /*
  587          * If our class cares about being spoiled, and we have been, we
  588          * are probably just ahead of the event telling us that.  Fail
  589          * now rather than having to unravel this later.
  590          */
  591         if (cp->geom->spoiled != NULL && cp->spoiled) {
  592                 KASSERT(dcr <= 0, ("spoiled but dcr = %d", dcr));
  593                 KASSERT(dcw <= 0, ("spoiled but dce = %d", dcw));
  594                 KASSERT(dce <= 0, ("spoiled but dcw = %d", dce));
  595         }
  596 
  597         /*
  598          * Figure out what counts the provider would have had, if this
  599          * consumer had (r0w0e0) at this time.
  600          */
  601         pr = pp->acr - cp->acr;
  602         pw = pp->acw - cp->acw;
  603         pe = pp->ace - cp->ace;
  604 
  605         g_trace(G_T_ACCESS,
  606     "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
  607             dcr, dcw, dce,
  608             cp->acr, cp->acw, cp->ace,
  609             pp->acr, pp->acw, pp->ace,
  610             pp, pp->name);
  611 
  612         /* If foot-shooting is enabled, any open on rank#1 is OK */
  613         if ((g_debugflags & 16) && pp->geom->rank == 1)
  614                 ;
  615         /* If we try exclusive but already write: fail */
  616         else if (dce > 0 && pw > 0)
  617                 return (EPERM);
  618         /* If we try write but already exclusive: fail */
  619         else if (dcw > 0 && pe > 0)
  620                 return (EPERM);
  621         /* If we try to open more but provider is error'ed: fail */
  622         else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
  623                 return (pp->error);
  624 
  625         /* Ok then... */
  626 
  627         error = pp->geom->access(pp, dcr, dcw, dce);
  628         if (!error) {
  629                 /*
  630                  * If we open first write, spoil any partner consumers.
  631                  * If we close last write, trigger re-taste.
  632                  */
  633                 if (pp->acw == 0 && dcw != 0)
  634                         g_spoil(pp, cp);
  635                 else if (pp->acw != 0 && pp->acw == -dcw && 
  636                     !(pp->geom->flags & G_GEOM_WITHER))
  637                         g_post_event(g_new_provider_event, pp, M_WAITOK, 
  638                             pp, NULL);
  639 
  640                 pp->acr += dcr;
  641                 pp->acw += dcw;
  642                 pp->ace += dce;
  643                 cp->acr += dcr;
  644                 cp->acw += dcw;
  645                 cp->ace += dce;
  646         }
  647         return (error);
  648 }
  649 
  650 int
  651 g_handleattr_int(struct bio *bp, const char *attribute, int val)
  652 {
  653 
  654         return (g_handleattr(bp, attribute, &val, sizeof val));
  655 }
  656 
  657 int
  658 g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
  659 {
  660 
  661         return (g_handleattr(bp, attribute, &val, sizeof val));
  662 }
  663 
  664 int
  665 g_handleattr(struct bio *bp, const char *attribute, void *val, int len)
  666 {
  667         int error;
  668 
  669         if (strcmp(bp->bio_attribute, attribute))
  670                 return (0);
  671         if (bp->bio_length != len) {
  672                 printf("bio_length %jd len %d -> EFAULT\n",
  673                     (intmax_t)bp->bio_length, len);
  674                 error = EFAULT;
  675         } else {
  676                 error = 0;
  677                 bcopy(val, bp->bio_data, len);
  678                 bp->bio_completed = len;
  679         }
  680         g_io_deliver(bp, error);
  681         return (1);
  682 }
  683 
  684 int
  685 g_std_access(struct g_provider *pp __unused,
  686         int dr __unused, int dw __unused, int de __unused)
  687 {
  688 
  689         return (0);
  690 }
  691 
  692 void
  693 g_std_done(struct bio *bp)
  694 {
  695         struct bio *bp2;
  696 
  697         bp2 = bp->bio_parent;
  698         if (bp2->bio_error == 0)
  699                 bp2->bio_error = bp->bio_error;
  700         bp2->bio_completed += bp->bio_completed;
  701         g_destroy_bio(bp);
  702         bp2->bio_inbed++;
  703         if (bp2->bio_children == bp2->bio_inbed)
  704                 g_io_deliver(bp2, bp2->bio_error);
  705 }
  706 
  707 /* XXX: maybe this is only g_slice_spoiled */
  708 
  709 void
  710 g_std_spoiled(struct g_consumer *cp)
  711 {
  712         struct g_geom *gp;
  713         struct g_provider *pp;
  714 
  715         g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
  716         g_topology_assert();
  717         g_detach(cp);
  718         gp = cp->geom;
  719         LIST_FOREACH(pp, &gp->provider, provider)
  720                 g_orphan_provider(pp, ENXIO);
  721         g_destroy_consumer(cp);
  722         if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
  723                 g_destroy_geom(gp);
  724         else
  725                 gp->flags |= G_GEOM_WITHER;
  726 }
  727 
  728 /*
  729  * Spoiling happens when a provider is opened for writing, but consumers
  730  * which are configured by in-band data are attached (slicers for instance).
  731  * Since the write might potentially change the in-band data, such consumers
  732  * need to re-evaluate their existence after the writing session closes.
  733  * We do this by (offering to) tear them down when the open for write happens
  734  * in return for a re-taste when it closes again.
  735  * Together with the fact that such consumers grab an 'e' bit whenever they
  736  * are open, regardless of mode, this ends up DTRT.
  737  */
  738 
  739 static void
  740 g_spoil_event(void *arg, int flag)
  741 {
  742         struct g_provider *pp;
  743         struct g_consumer *cp, *cp2;
  744 
  745         g_topology_assert();
  746         if (flag == EV_CANCEL)
  747                 return;
  748         pp = arg;
  749         for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
  750                 cp2 = LIST_NEXT(cp, consumers);
  751                 if (!cp->spoiled)
  752                         continue;
  753                 cp->spoiled = 0;
  754                 if (cp->geom->spoiled == NULL)
  755                         continue;
  756                 cp->geom->spoiled(cp);
  757                 g_topology_assert();
  758         }
  759 }
  760 
  761 void
  762 g_spoil(struct g_provider *pp, struct g_consumer *cp)
  763 {
  764         struct g_consumer *cp2;
  765 
  766         g_topology_assert();
  767 
  768         LIST_FOREACH(cp2, &pp->consumers, consumers) {
  769                 if (cp2 == cp)
  770                         continue;
  771 /*
  772                 KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
  773                 KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
  774 */
  775                 KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
  776                 cp2->spoiled++;
  777         }
  778         g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
  779 }
  780 
  781 int
  782 g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
  783 {
  784         int error, i;
  785 
  786         i = len;
  787         error = g_io_getattr(attr, cp, &i, var);
  788         if (error)
  789                 return (error);
  790         if (i != len)
  791                 return (EINVAL);
  792         return (0);
  793 }
  794 
  795 /*
  796  * XXX: Bandaid for 5.2.
  797  * XXX: DO NOT EVEN THINK ABOUT CALLING THIS FUNCTION!
  798  */
  799 static int
  800 g_valid_obj(void const *ptr)
  801 {
  802         struct g_class *mp;
  803         struct g_geom *gp;
  804         struct g_consumer *cp;
  805         struct g_provider *pp;
  806 
  807         g_topology_assert();
  808         LIST_FOREACH(mp, &g_classes, class) {
  809                 if (ptr == mp)
  810                         return (1);
  811                 LIST_FOREACH(gp, &mp->geom, geom) {
  812                         if (ptr == gp)
  813                                 return (1);
  814                         LIST_FOREACH(cp, &gp->consumer, consumer)
  815                                 if (ptr == cp)
  816                                         return (1);
  817                         LIST_FOREACH(pp, &gp->provider, provider)
  818                                 if (ptr == pp)
  819                                         return (1);
  820                 }
  821         }
  822         return(0);
  823 }
  824 
  825 /*
  826  * Check if the given pointer is a live object
  827  */
  828 
  829 void
  830 g_sanity(void const *ptr)
  831 {
  832         struct g_class *mp;
  833         struct g_geom *gp;
  834         struct g_consumer *cp;
  835         struct g_provider *pp;
  836 
  837         if (!(g_debugflags & 0x8))
  838                 return;
  839         LIST_FOREACH(mp, &g_classes, class) {
  840                 KASSERT(mp != ptr, ("Ptr is live class"));
  841                 LIST_FOREACH(gp, &mp->geom, geom) {
  842                         KASSERT(gp != ptr, ("Ptr is live geom"));
  843                         KASSERT(gp->name != ptr, ("Ptr is live geom's name"));
  844                         LIST_FOREACH(cp, &gp->consumer, consumer) {
  845                                 KASSERT(cp != ptr, ("Ptr is live consumer"));
  846                         }
  847                         LIST_FOREACH(pp, &gp->provider, provider) {
  848                                 KASSERT(pp != ptr, ("Ptr is live provider"));
  849                         }
  850                 }
  851         }
  852 }
  853 

Cache object: ed9d4d0feb56b56d7e90e03f64bc6a8d


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.