diff options
Diffstat (limited to 'sys/geom/geom_subr.c')
| -rw-r--r-- | sys/geom/geom_subr.c | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/sys/geom/geom_subr.c b/sys/geom/geom_subr.c new file mode 100644 index 0000000..a458550 --- /dev/null +++ b/sys/geom/geom_subr.c @@ -0,0 +1,639 @@ +/*- + * 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 <machine/stdarg.h> + +struct method_list_head g_methods = LIST_HEAD_INITIALIZER(g_methods); +static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms); +static int g_nproviders; +char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim; + +static int g_ignition; + +void +g_add_method(struct g_method *mp) +{ + + if (!g_ignition) { + g_ignition++; + g_init(); + } + g_topology_lock(); + g_trace(G_T_TOPOLOGY, "g_add_method(%s)", mp->name); + LIST_INIT(&mp->geom); + LIST_INSERT_HEAD(&g_methods, mp, method); + if (g_nproviders > 0) + g_post_event(EV_NEW_METHOD, mp, NULL, NULL, NULL); + g_topology_unlock(); +} + +struct g_geom * +g_new_geomf(struct g_method *mp, char *fmt, ...) +{ + struct g_geom *gp; + va_list ap; + struct sbuf *sb; + + g_topology_assert(); + va_start(ap, fmt); + mtx_lock(&Giant); + sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); + sbuf_vprintf(sb, fmt, ap); + sbuf_finish(sb); + mtx_unlock(&Giant); + gp = g_malloc(sizeof *gp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO); + gp->name = (char *)(gp + 1); + gp->method = 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(gp->event == NULL, ("g_destroy_geom() with event")); + 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))); + LIST_REMOVE(gp, geom); + TAILQ_REMOVE(&geoms, gp, geoms); + g_free(gp); +} + +struct g_consumer * +g_new_consumer(struct g_geom *gp) +{ + struct g_consumer *cp; + + g_topology_assert(); + KASSERT(gp->method->orphan != NULL, + ("g_new_consumer on method(%s) without orphan", gp->method->name)); + + cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO); + cp->geom = gp; + LIST_INSERT_HEAD(&gp->consumer, cp, consumer); + return(cp); +} + +void +g_destroy_consumer(struct g_consumer *cp) +{ + + g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp); + g_topology_assert(); + KASSERT(cp->event == NULL, ("g_destroy_consumer() with event")); + 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")); + LIST_REMOVE(cp, consumer); + g_free(cp); +} + +struct g_provider * +g_new_providerf(struct g_geom *gp, char *fmt, ...) +{ + struct g_provider *pp; + struct sbuf *sb; + va_list ap; + + g_topology_assert(); + va_start(ap, fmt); + mtx_lock(&Giant); + sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); + sbuf_vprintf(sb, fmt, ap); + sbuf_finish(sb); + mtx_unlock(&Giant); + pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO); + pp->name = (char *)(pp + 1); + strcpy(pp->name, sbuf_data(sb)); + sbuf_delete(sb); + LIST_INIT(&pp->consumers); + pp->error = ENXIO; + pp->geom = gp; + LIST_INSERT_HEAD(&gp->provider, pp, provider); + g_nproviders++; + g_post_event(EV_NEW_PROVIDER, NULL, NULL, 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; + struct g_consumer *cp; + + g_topology_assert(); + KASSERT(pp->event == NULL, ("g_destroy_provider() with event")); + 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_nproviders--; + LIST_REMOVE(pp, provider); + gp = pp->geom; + g_free(pp); + if (!(gp->flags & G_GEOM_WITHER)) + return; + if (!LIST_EMPTY(&gp->provider)) + return; + for (;;) { + cp = LIST_FIRST(&gp->consumer); + if (cp == NULL) + break; + g_dettach(cp); + g_destroy_consumer(cp); + } + g_destroy_geom(gp); +} + +/* + * 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 dettach 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_dettach(struct g_consumer *cp) +{ + struct g_provider *pp; + + g_trace(G_T_TOPOLOGY, "g_dettach(%p)", cp); + KASSERT(cp != (void*)0xd0d0d0d0, ("ARGH!")); + g_topology_assert(); + KASSERT(cp->provider != NULL, ("dettach but not attached")); + KASSERT(cp->acr == 0, ("dettach but nonzero acr")); + KASSERT(cp->acw == 0, ("dettach but nonzero acw")); + KASSERT(cp->ace == 0, ("dettach but nonzero ace")); + KASSERT(cp->biocount == 0, ("dettach but nonzero biocount")); + pp = cp->provider; + LIST_REMOVE(cp, consumers); + cp->provider = NULL; + if (LIST_EMPTY(&pp->consumers)) { + if (pp->geom->flags & G_GEOM_WITHER) + g_destroy_provider(pp); + } + 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->method->access != NULL, ("NULL method->access")); + + /* + * If our method 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)); + KASSERT(cp->acr == 0, ("spoiled but cp->acr = %d", cp->acr)); + KASSERT(cp->acw == 0, ("spoiled but cp->acw = %d", cp->acw)); + KASSERT(cp->ace == 0, ("spoiled but cp->ace = %d", cp->ace)); + return(ENXIO); + } + + /* + * 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 we try exclusive but already write: fail */ + if (dce > 0 && pw > 0) + return (EPERM); + /* If we try write but already exclusive: fail */ + if (dcw > 0 && pe > 0) + return (EPERM); + /* If we try to open more but provider is error'ed: fail */ + if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0) + return (pp->error); + + /* Ok then... */ + + /* + * 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(EV_NEW_PROVIDER, NULL, NULL, pp, NULL); + + error = pp->geom->method->access(pp, dcr, dcw, dce); + if (!error) { + pp->acr += dcr; + pp->acw += dcw; + pp->ace += dce; + cp->acr += dcr; + cp->acw += dcw; + cp->ace += dce; + } + return (error); +} + +int +g_haveattr_int(struct bio *bp, char *attribute, int val) +{ + + return (g_haveattr(bp, attribute, &val, sizeof val)); +} + +int +g_haveattr_off_t(struct bio *bp, char *attribute, off_t val) +{ + + return (g_haveattr(bp, attribute, &val, sizeof val)); +} + + +int +g_haveattr(struct bio *bp, char *attribute, void *val, int len) +{ + int error; + + if (strcmp(bp->bio_attribute, attribute)) + return (0); + if (bp->bio_length != len) { + printf("bio_length %lld len %d -> EFAULT\n", bp->bio_length, len); + error = EFAULT; + } else { + error = 0; + bcopy(val, bp->bio_data, len); + bp->bio_completed = len; + } + bp->bio_error = error; + g_io_deliver(bp); + 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_linkage; + bp2->bio_error = bp->bio_error; + bp2->bio_completed = bp->bio_completed; + g_destroy_bio(bp); + g_io_deliver(bp2); +} + +/* 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_dettach(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. + */ + +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(EV_SPOILED, NULL, NULL, pp, cp); +} + +static struct g_method * +g_method_by_name(char *name) +{ + struct g_method *mp; + + g_trace(G_T_TOPOLOGY, "g_method_by_name(%s)", name); + g_topology_assert(); + LIST_FOREACH(mp, &g_methods, method) + if (!strcmp(mp->name, name)) + return (mp); + return (NULL); +} + +struct g_geom * +g_create_geomf(char *method, struct g_provider *pp, char *fmt, ...) +{ + va_list ap; + struct sbuf *sb; + char *s; + struct g_method *mp; + struct g_geom *gp; + + g_trace(G_T_TOPOLOGY, "g_create_geom(%s, %p(%s))", method, + pp, pp == NULL ? "" : pp->name); + g_topology_assert(); + gp = NULL; + mp = g_method_by_name(method); + if (mp == NULL) + return (NULL); + if (fmt != NULL) { + va_start(ap, fmt); + mtx_lock(&Giant); + sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); + sbuf_vprintf(sb, fmt, ap); + sbuf_finish(sb); + mtx_unlock(&Giant); + s = sbuf_data(sb); + } else { + s = NULL; + } + if (pp != NULL) + gp = mp->taste(mp, pp, NULL, G_TF_INSIST); + if (gp == NULL && mp->create_geom == NULL) + return (NULL); + if (gp == NULL) + gp = mp->create_geom(mp, pp, s); + /* XXX: delete sbuf */ + return (gp); +} + +struct g_geom * +g_insert_geom(char *method, struct g_consumer *cp) +{ + struct g_method *mp; + struct g_geom *gp; + struct g_provider *pp, *pp2; + struct g_consumer *cp2; + int error; + + g_trace(G_T_TOPOLOGY, "g_insert_geomf(%s, %p)", method, cp); + g_topology_assert(); + KASSERT(cp->provider != NULL, ("g_insert_geomf but not attached")); + /* XXX: check for events ?? */ + mp = g_method_by_name(method); + if (mp == NULL) + return (NULL); + if (mp->create_geom == NULL) + return (NULL); + pp = cp->provider; + gp = mp->taste(mp, pp, NULL, G_TF_TRANSPARENT); + if (gp == NULL) + return (NULL); + pp2 = LIST_FIRST(&gp->provider); + cp2 = LIST_FIRST(&gp->consumer); + cp2->acr += pp->acr; + cp2->acw += pp->acw; + cp2->ace += pp->ace; + pp2->acr += pp->acr; + pp2->acw += pp->acw; + pp2->ace += pp->ace; + LIST_REMOVE(cp, consumers); + LIST_INSERT_HEAD(&pp2->consumers, cp, consumers); + cp->provider = pp2; + error = redo_rank(gp); + KASSERT(error == 0, ("redo_rank failed in g_insert_geom")); + return (gp); +} + |
