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-rw-r--r--sys/geom/geom_subr.c797
1 files changed, 797 insertions, 0 deletions
diff --git a/sys/geom/geom_subr.c b/sys/geom/geom_subr.c
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--- /dev/null
+++ b/sys/geom/geom_subr.c
@@ -0,0 +1,797 @@
+/*-
+ * 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>
+#include <sys/systm.h>
+#include <sys/devicestat.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>
+#include <sys/errno.h>
+#include <sys/sbuf.h>
+#include <geom/geom.h>
+#include <geom/geom_int.h>
+#include <machine/stdarg.h>
+
+struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
+static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
+char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
+
+
+struct g_hh00 {
+ struct g_class *mp;
+ int error;
+};
+
+/*
+ * This event offers a new class a chance to taste all preexisting providers.
+ */
+static void
+g_load_class(void *arg, int flag)
+{
+ struct g_hh00 *hh;
+ struct g_class *mp2, *mp;
+ struct g_geom *gp;
+ struct g_provider *pp;
+
+ g_topology_assert();
+ if (flag == EV_CANCEL) /* XXX: can't happen ? */
+ return;
+ if (g_shutdown)
+ return;
+
+ hh = arg;
+ mp = hh->mp;
+ g_free(hh);
+ g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
+
+ if (mp->init != NULL)
+ mp->init(mp);
+ LIST_INIT(&mp->geom);
+ LIST_INSERT_HEAD(&g_classes, mp, class);
+ if (mp->taste == NULL)
+ return;
+ LIST_FOREACH(mp2, &g_classes, class) {
+ if (mp == mp2)
+ continue;
+ LIST_FOREACH(gp, &mp2->geom, geom) {
+ LIST_FOREACH(pp, &gp->provider, provider) {
+ mp->taste(mp, pp, 0);
+ g_topology_assert();
+ }
+ }
+ }
+}
+
+static void
+g_unload_class(void *arg, int flag)
+{
+ struct g_hh00 *hh;
+ struct g_class *mp;
+ struct g_geom *gp;
+ struct g_provider *pp;
+ struct g_consumer *cp;
+ int error;
+
+ g_topology_assert();
+ hh = arg;
+ mp = hh->mp;
+ g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
+ if (mp->destroy_geom == NULL) {
+ hh->error = EOPNOTSUPP;
+ return;
+ }
+
+ /* We refuse to unload if anything is open */
+ LIST_FOREACH(gp, &mp->geom, geom) {
+ LIST_FOREACH(pp, &gp->provider, provider)
+ if (pp->acr || pp->acw || pp->ace) {
+ hh->error = EBUSY;
+ return;
+ }
+ LIST_FOREACH(cp, &gp->consumer, consumer)
+ if (cp->acr || cp->acw || cp->ace) {
+ hh->error = EBUSY;
+ return;
+ }
+ }
+
+ /* Bar new entries */
+ mp->taste = NULL;
+ mp->config = NULL;
+
+ error = 0;
+ LIST_FOREACH(gp, &mp->geom, geom) {
+ error = mp->destroy_geom(NULL, mp, gp);
+ if (error != 0)
+ break;
+ }
+ if (error == 0) {
+ LIST_REMOVE(mp, class);
+ if (mp->fini != NULL)
+ mp->fini(mp);
+ }
+ hh->error = error;
+ return;
+}
+
+int
+g_modevent(module_t mod, int type, void *data)
+{
+ struct g_hh00 *hh;
+ int error;
+ static int g_ignition;
+
+ if (!g_ignition) {
+ g_ignition++;
+ g_init();
+ }
+ hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
+ hh->mp = data;
+ error = EOPNOTSUPP;
+ switch (type) {
+ case MOD_LOAD:
+ g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", hh->mp->name);
+ g_post_event(g_load_class, hh, M_WAITOK, NULL);
+ error = 0;
+ break;
+ case MOD_UNLOAD:
+ g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", hh->mp->name);
+ error = g_waitfor_event(g_unload_class, hh, M_WAITOK, NULL);
+ if (error == 0)
+ error = hh->error;
+ g_waitidle();
+ KASSERT(LIST_EMPTY(&hh->mp->geom),
+ ("Unloaded class (%s) still has geom", hh->mp->name));
+ g_free(hh);
+ break;
+ }
+ return (error);
+}
+
+struct g_geom *
+g_new_geomf(struct g_class *mp, const char *fmt, ...)
+{
+ struct g_geom *gp;
+ va_list ap;
+ struct sbuf *sb;
+
+ g_topology_assert();
+ va_start(ap, fmt);
+ sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
+ sbuf_vprintf(sb, fmt, ap);
+ sbuf_finish(sb);
+ gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
+ gp->protect = 0x020016601;
+ gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
+ gp->class = mp;
+ gp->rank = 1;
+ LIST_INIT(&gp->consumer);
+ LIST_INIT(&gp->provider);
+ LIST_INSERT_HEAD(&mp->geom, gp, geom);
+ TAILQ_INSERT_HEAD(&geoms, gp, geoms);
+ strcpy(gp->name, sbuf_data(sb));
+ sbuf_delete(sb);
+ return (gp);
+}
+
+void
+g_destroy_geom(struct g_geom *gp)
+{
+
+ g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
+ g_topology_assert();
+ KASSERT(LIST_EMPTY(&gp->consumer),
+ ("g_destroy_geom(%s) with consumer(s) [%p]",
+ gp->name, LIST_FIRST(&gp->consumer)));
+ KASSERT(LIST_EMPTY(&gp->provider),
+ ("g_destroy_geom(%s) with provider(s) [%p]",
+ gp->name, LIST_FIRST(&gp->consumer)));
+ g_cancel_event(gp);
+ LIST_REMOVE(gp, geom);
+ TAILQ_REMOVE(&geoms, gp, geoms);
+ g_free(gp->name);
+ g_free(gp);
+}
+
+/*
+ * This function is called (repeatedly) until has withered away.
+ */
+void
+g_wither_geom(struct g_geom *gp, int error)
+{
+ struct g_provider *pp, *pp2;
+ struct g_consumer *cp, *cp2;
+ static int once_is_enough;
+
+ if (once_is_enough)
+ return;
+ once_is_enough = 1;
+ g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
+ g_topology_assert();
+ if (!(gp->flags & G_GEOM_WITHER)) {
+ gp->flags |= G_GEOM_WITHER;
+ LIST_FOREACH(pp, &gp->provider, provider)
+ g_orphan_provider(pp, error);
+ }
+ for (pp = LIST_FIRST(&gp->provider); pp != NULL; pp = pp2) {
+ pp2 = LIST_NEXT(pp, provider);
+ if (!LIST_EMPTY(&pp->consumers))
+ continue;
+ g_destroy_provider(pp);
+ }
+ for (cp = LIST_FIRST(&gp->consumer); cp != NULL; cp = cp2) {
+ cp2 = LIST_NEXT(cp, consumer);
+ if (cp->acr || cp->acw || cp->ace)
+ continue;
+ g_detach(cp);
+ g_destroy_consumer(cp);
+ }
+ if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
+ g_destroy_geom(gp);
+ once_is_enough = 0;
+}
+
+struct g_consumer *
+g_new_consumer(struct g_geom *gp)
+{
+ struct g_consumer *cp;
+
+ g_topology_assert();
+ KASSERT(gp->orphan != NULL,
+ ("g_new_consumer on geom(%s) (class %s) without orphan",
+ gp->name, gp->class->name));
+
+ cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
+ cp->protect = 0x020016602;
+ cp->geom = gp;
+ cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
+ DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
+ LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
+ return(cp);
+}
+
+void
+g_destroy_consumer(struct g_consumer *cp)
+{
+ struct g_geom *gp;
+
+ g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
+ g_topology_assert();
+ KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
+ KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
+ KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
+ KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
+ g_cancel_event(cp);
+ gp = cp->geom;
+ LIST_REMOVE(cp, consumer);
+ devstat_remove_entry(cp->stat);
+ g_free(cp);
+ if (gp->flags & G_GEOM_WITHER)
+ g_wither_geom(gp, 0);
+}
+
+static void
+g_new_provider_event(void *arg, int flag)
+{
+ struct g_class *mp;
+ struct g_provider *pp;
+ struct g_consumer *cp;
+ int i;
+
+ g_topology_assert();
+ if (flag == EV_CANCEL)
+ return;
+ if (g_shutdown)
+ return;
+ pp = arg;
+ LIST_FOREACH(mp, &g_classes, class) {
+ if (mp->taste == NULL)
+ continue;
+ i = 1;
+ LIST_FOREACH(cp, &pp->consumers, consumers)
+ if (cp->geom->class == mp)
+ i = 0;
+ if (!i)
+ continue;
+ mp->taste(mp, pp, 0);
+ g_topology_assert();
+ }
+}
+
+
+struct g_provider *
+g_new_providerf(struct g_geom *gp, const char *fmt, ...)
+{
+ struct g_provider *pp;
+ struct sbuf *sb;
+ va_list ap;
+
+ g_topology_assert();
+ va_start(ap, fmt);
+ sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
+ sbuf_vprintf(sb, fmt, ap);
+ sbuf_finish(sb);
+ pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
+ pp->protect = 0x020016603;
+ pp->name = (char *)(pp + 1);
+ strcpy(pp->name, sbuf_data(sb));
+ sbuf_delete(sb);
+ LIST_INIT(&pp->consumers);
+ pp->error = ENXIO;
+ pp->geom = gp;
+ pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
+ DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
+ LIST_INSERT_HEAD(&gp->provider, pp, provider);
+ g_post_event(g_new_provider_event, pp, M_WAITOK, pp, NULL);
+ return (pp);
+}
+
+void
+g_error_provider(struct g_provider *pp, int error)
+{
+
+ pp->error = error;
+}
+
+
+void
+g_destroy_provider(struct g_provider *pp)
+{
+ struct g_geom *gp;
+
+ g_topology_assert();
+ KASSERT(LIST_EMPTY(&pp->consumers),
+ ("g_destroy_provider but attached"));
+ KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
+ KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
+ KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
+ g_cancel_event(pp);
+ LIST_REMOVE(pp, provider);
+ gp = pp->geom;
+ devstat_remove_entry(pp->stat);
+ g_free(pp);
+ if ((gp->flags & G_GEOM_WITHER))
+ g_wither_geom(gp, 0);
+}
+
+/*
+ * We keep the "geoms" list sorted by topological order (== increasing
+ * numerical rank) at all times.
+ * When an attach is done, the attaching geoms rank is invalidated
+ * and it is moved to the tail of the list.
+ * All geoms later in the sequence has their ranks reevaluated in
+ * sequence. If we cannot assign rank to a geom because it's
+ * prerequisites do not have rank, we move that element to the tail
+ * of the sequence with invalid rank as well.
+ * At some point we encounter our original geom and if we stil fail
+ * to assign it a rank, there must be a loop and we fail back to
+ * g_attach() which detach again and calls redo_rank again
+ * to fix up the damage.
+ * It would be much simpler code wise to do it recursively, but we
+ * can't risk that on the kernel stack.
+ */
+
+static int
+redo_rank(struct g_geom *gp)
+{
+ struct g_consumer *cp;
+ struct g_geom *gp1, *gp2;
+ int n, m;
+
+ g_topology_assert();
+
+ /* Invalidate this geoms rank and move it to the tail */
+ gp1 = TAILQ_NEXT(gp, geoms);
+ if (gp1 != NULL) {
+ gp->rank = 0;
+ TAILQ_REMOVE(&geoms, gp, geoms);
+ TAILQ_INSERT_TAIL(&geoms, gp, geoms);
+ } else {
+ gp1 = gp;
+ }
+
+ /* re-rank the rest of the sequence */
+ for (; gp1 != NULL; gp1 = gp2) {
+ gp1->rank = 0;
+ m = 1;
+ LIST_FOREACH(cp, &gp1->consumer, consumer) {
+ if (cp->provider == NULL)
+ continue;
+ n = cp->provider->geom->rank;
+ if (n == 0) {
+ m = 0;
+ break;
+ } else if (n >= m)
+ m = n + 1;
+ }
+ gp1->rank = m;
+ gp2 = TAILQ_NEXT(gp1, geoms);
+
+ /* got a rank, moving on */
+ if (m != 0)
+ continue;
+
+ /* no rank to original geom means loop */
+ if (gp == gp1)
+ return (ELOOP);
+
+ /* no rank, put it at the end move on */
+ TAILQ_REMOVE(&geoms, gp1, geoms);
+ TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
+ }
+ return (0);
+}
+
+int
+g_attach(struct g_consumer *cp, struct g_provider *pp)
+{
+ int error;
+
+ g_topology_assert();
+ KASSERT(cp->provider == NULL, ("attach but attached"));
+ cp->provider = pp;
+ LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
+ error = redo_rank(cp->geom);
+ if (error) {
+ LIST_REMOVE(cp, consumers);
+ cp->provider = NULL;
+ redo_rank(cp->geom);
+ }
+ return (error);
+}
+
+void
+g_detach(struct g_consumer *cp)
+{
+ struct g_provider *pp;
+
+ g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
+ KASSERT(cp != (void*)0xd0d0d0d0, ("ARGH!"));
+ g_topology_assert();
+ KASSERT(cp->provider != NULL, ("detach but not attached"));
+ KASSERT(cp->acr == 0, ("detach but nonzero acr"));
+ KASSERT(cp->acw == 0, ("detach but nonzero acw"));
+ KASSERT(cp->ace == 0, ("detach but nonzero ace"));
+ KASSERT(cp->nstart == cp->nend,
+ ("detach with active requests"));
+ pp = cp->provider;
+ LIST_REMOVE(cp, consumers);
+ cp->provider = NULL;
+ if (pp->geom->flags & G_GEOM_WITHER)
+ g_wither_geom(pp->geom, 0);
+ redo_rank(cp->geom);
+}
+
+
+/*
+ * g_access_abs()
+ *
+ * Access-check with absolute new values: Just fall through
+ * and use the relative version.
+ */
+int
+g_access_abs(struct g_consumer *cp, int acr, int acw, int ace)
+{
+
+ g_topology_assert();
+ return(g_access_rel(cp,
+ acr - cp->acr,
+ acw - cp->acw,
+ ace - cp->ace));
+}
+
+/*
+ * g_access_rel()
+ *
+ * Access-check with delta values. The question asked is "can provider
+ * "cp" change the access counters by the relative amounts dc[rwe] ?"
+ */
+
+int
+g_access_rel(struct g_consumer *cp, int dcr, int dcw, int dce)
+{
+ struct g_provider *pp;
+ int pr,pw,pe;
+ int error;
+
+ pp = cp->provider;
+
+ g_trace(G_T_ACCESS, "g_access_rel(%p(%s), %d, %d, %d)",
+ cp, pp->name, dcr, dcw, dce);
+
+ g_topology_assert();
+ KASSERT(cp->provider != NULL, ("access but not attached"));
+ KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
+ KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
+ KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
+ KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
+
+ /*
+ * If our class cares about being spoiled, and we have been, we
+ * are probably just ahead of the event telling us that. Fail
+ * now rather than having to unravel this later.
+ */
+ if (cp->geom->spoiled != NULL && cp->spoiled) {
+ KASSERT(dcr <= 0, ("spoiled but dcr = %d", dcr));
+ KASSERT(dcw <= 0, ("spoiled but dce = %d", dcw));
+ KASSERT(dce <= 0, ("spoiled but dcw = %d", dce));
+ }
+
+ /*
+ * Figure out what counts the provider would have had, if this
+ * consumer had (r0w0e0) at this time.
+ */
+ pr = pp->acr - cp->acr;
+ pw = pp->acw - cp->acw;
+ pe = pp->ace - cp->ace;
+
+ g_trace(G_T_ACCESS,
+ "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
+ dcr, dcw, dce,
+ cp->acr, cp->acw, cp->ace,
+ pp->acr, pp->acw, pp->ace,
+ pp, pp->name);
+
+ /* If foot-shooting is enabled, any open on rank#1 is OK */
+ if ((g_debugflags & 16) && pp->geom->rank == 1)
+ ;
+ /* If we try exclusive but already write: fail */
+ else if (dce > 0 && pw > 0)
+ return (EPERM);
+ /* If we try write but already exclusive: fail */
+ else if (dcw > 0 && pe > 0)
+ return (EPERM);
+ /* If we try to open more but provider is error'ed: fail */
+ else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
+ return (pp->error);
+
+ /* Ok then... */
+
+ error = pp->geom->access(pp, dcr, dcw, dce);
+ if (!error) {
+ /*
+ * If we open first write, spoil any partner consumers.
+ * If we close last write, trigger re-taste.
+ */
+ if (pp->acw == 0 && dcw != 0)
+ g_spoil(pp, cp);
+ else if (pp->acw != 0 && pp->acw == -dcw &&
+ !(pp->geom->flags & G_GEOM_WITHER))
+ g_post_event(g_new_provider_event, pp, M_WAITOK,
+ pp, NULL);
+
+ pp->acr += dcr;
+ pp->acw += dcw;
+ pp->ace += dce;
+ cp->acr += dcr;
+ cp->acw += dcw;
+ cp->ace += dce;
+ }
+ return (error);
+}
+
+int
+g_handleattr_int(struct bio *bp, const char *attribute, int val)
+{
+
+ return (g_handleattr(bp, attribute, &val, sizeof val));
+}
+
+int
+g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
+{
+
+ return (g_handleattr(bp, attribute, &val, sizeof val));
+}
+
+int
+g_handleattr(struct bio *bp, const char *attribute, void *val, int len)
+{
+ int error;
+
+ if (strcmp(bp->bio_attribute, attribute))
+ return (0);
+ if (bp->bio_length != len) {
+ printf("bio_length %jd len %d -> EFAULT\n",
+ (intmax_t)bp->bio_length, len);
+ error = EFAULT;
+ } else {
+ error = 0;
+ bcopy(val, bp->bio_data, len);
+ bp->bio_completed = len;
+ }
+ g_io_deliver(bp, error);
+ return (1);
+}
+
+int
+g_std_access(struct g_provider *pp __unused,
+ int dr __unused, int dw __unused, int de __unused)
+{
+
+ return (0);
+}
+
+void
+g_std_done(struct bio *bp)
+{
+ struct bio *bp2;
+
+ bp2 = bp->bio_parent;
+ if (bp2->bio_error == 0)
+ bp2->bio_error = bp->bio_error;
+ bp2->bio_completed += bp->bio_completed;
+ g_destroy_bio(bp);
+ bp2->bio_inbed++;
+ if (bp2->bio_children == bp2->bio_inbed)
+ g_io_deliver(bp2, bp2->bio_error);
+}
+
+/* XXX: maybe this is only g_slice_spoiled */
+
+void
+g_std_spoiled(struct g_consumer *cp)
+{
+ struct g_geom *gp;
+ struct g_provider *pp;
+
+ g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
+ g_topology_assert();
+ g_detach(cp);
+ gp = cp->geom;
+ LIST_FOREACH(pp, &gp->provider, provider)
+ g_orphan_provider(pp, ENXIO);
+ g_destroy_consumer(cp);
+ if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
+ g_destroy_geom(gp);
+ else
+ gp->flags |= G_GEOM_WITHER;
+}
+
+/*
+ * Spoiling happens when a provider is opened for writing, but consumers
+ * which are configured by in-band data are attached (slicers for instance).
+ * Since the write might potentially change the in-band data, such consumers
+ * need to re-evaluate their existence after the writing session closes.
+ * We do this by (offering to) tear them down when the open for write happens
+ * in return for a re-taste when it closes again.
+ * Together with the fact that such consumers grab an 'e' bit whenever they
+ * are open, regardless of mode, this ends up DTRT.
+ */
+
+static void
+g_spoil_event(void *arg, int flag)
+{
+ struct g_provider *pp;
+ struct g_consumer *cp, *cp2;
+
+ g_topology_assert();
+ if (flag == EV_CANCEL)
+ return;
+ pp = arg;
+ for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
+ cp2 = LIST_NEXT(cp, consumers);
+ if (!cp->spoiled)
+ continue;
+ cp->spoiled = 0;
+ if (cp->geom->spoiled == NULL)
+ continue;
+ cp->geom->spoiled(cp);
+ g_topology_assert();
+ }
+}
+
+void
+g_spoil(struct g_provider *pp, struct g_consumer *cp)
+{
+ struct g_consumer *cp2;
+
+ g_topology_assert();
+
+ LIST_FOREACH(cp2, &pp->consumers, consumers) {
+ if (cp2 == cp)
+ continue;
+/*
+ KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
+ KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
+*/
+ KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
+ cp2->spoiled++;
+ }
+ g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
+}
+
+int
+g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
+{
+ int error, i;
+
+ i = len;
+ error = g_io_getattr(attr, cp, &i, var);
+ if (error)
+ return (error);
+ if (i != len)
+ return (EINVAL);
+ return (0);
+}
+
+/*
+ * Check if the given pointer is a live object
+ */
+
+void
+g_sanity(void *ptr)
+{
+ struct g_class *mp;
+ struct g_geom *gp;
+ struct g_consumer *cp;
+ struct g_provider *pp;
+
+ if (!(g_debugflags & 0x8))
+ return;
+ LIST_FOREACH(mp, &g_classes, class) {
+ KASSERT(mp != ptr, ("Ptr is live class"));
+ KASSERT(mp->protect == 0x20016600,
+ ("corrupt class %p %x", mp, mp->protect));
+ LIST_FOREACH(gp, &mp->geom, geom) {
+ KASSERT(gp != ptr, ("Ptr is live geom"));
+ KASSERT(gp->protect == 0x20016601,
+ ("corrupt geom, %p %x", gp, gp->protect));
+ KASSERT(gp->name != ptr, ("Ptr is live geom's name"));
+ LIST_FOREACH(cp, &gp->consumer, consumer) {
+ KASSERT(cp != ptr, ("Ptr is live consumer"));
+ KASSERT(cp->protect == 0x20016602,
+ ("corrupt consumer %p %x",
+ cp, cp->protect));
+ }
+ LIST_FOREACH(pp, &gp->provider, provider) {
+ KASSERT(pp != ptr, ("Ptr is live provider"));
+ KASSERT(pp->protect == 0x20016603,
+ ("corrupt provider %p %x",
+ pp, pp->protect));
+ }
+ }
+ }
+}
+
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