Index: head/sys/geom/geom_disk.c =================================================================== --- head/sys/geom/geom_disk.c (revision 264319) +++ head/sys/geom/geom_disk.c (revision 264320) @@ -1,806 +1,806 @@ /*- * 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. */ #include __FBSDID("$FreeBSD$"); #include "opt_geom.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct g_disk_softc { struct mtx done_mtx; struct disk *dp; struct sysctl_ctx_list sysctl_ctx; struct sysctl_oid *sysctl_tree; char led[64]; uint32_t state; struct mtx start_mtx; }; static g_access_t g_disk_access; static g_start_t g_disk_start; static g_ioctl_t g_disk_ioctl; static g_dumpconf_t g_disk_dumpconf; static g_provgone_t g_disk_providergone; static struct g_class g_disk_class = { .name = G_DISK_CLASS_NAME, .version = G_VERSION, .start = g_disk_start, .access = g_disk_access, .ioctl = g_disk_ioctl, .providergone = g_disk_providergone, .dumpconf = g_disk_dumpconf, }; SYSCTL_DECL(_kern_geom); static SYSCTL_NODE(_kern_geom, OID_AUTO, disk, CTLFLAG_RW, 0, "GEOM_DISK stuff"); DECLARE_GEOM_CLASS(g_disk_class, g_disk); static int g_disk_access(struct g_provider *pp, int r, int w, int e) { struct disk *dp; struct g_disk_softc *sc; int error; g_trace(G_T_ACCESS, "g_disk_access(%s, %d, %d, %d)", pp->name, r, w, e); g_topology_assert(); sc = pp->private; if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) { /* * Allow decreasing access count even if disk is not * avaliable anymore. */ if (r <= 0 && w <= 0 && e <= 0) return (0); return (ENXIO); } r += pp->acr; w += pp->acw; e += pp->ace; error = 0; if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) { if (dp->d_open != NULL) { error = dp->d_open(dp); if (bootverbose && error != 0) printf("Opened disk %s -> %d\n", pp->name, error); if (error != 0) return (error); } pp->mediasize = dp->d_mediasize; pp->sectorsize = dp->d_sectorsize; if (dp->d_maxsize == 0) { printf("WARNING: Disk drive %s%d has no d_maxsize\n", dp->d_name, dp->d_unit); dp->d_maxsize = DFLTPHYS; } if (dp->d_delmaxsize == 0) { if (bootverbose && dp->d_flags & DISKFLAG_CANDELETE) { printf("WARNING: Disk drive %s%d has no " "d_delmaxsize\n", dp->d_name, dp->d_unit); } dp->d_delmaxsize = dp->d_maxsize; } pp->stripeoffset = dp->d_stripeoffset; pp->stripesize = dp->d_stripesize; dp->d_flags |= DISKFLAG_OPEN; } else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) { if (dp->d_close != NULL) { error = dp->d_close(dp); if (error != 0) printf("Closed disk %s -> %d\n", pp->name, error); } sc->state = G_STATE_ACTIVE; if (sc->led[0] != 0) led_set(sc->led, "0"); dp->d_flags &= ~DISKFLAG_OPEN; } return (error); } static void g_disk_kerneldump(struct bio *bp, struct disk *dp) { struct g_kerneldump *gkd; struct g_geom *gp; gkd = (struct g_kerneldump*)bp->bio_data; gp = bp->bio_to->geom; - g_trace(G_T_TOPOLOGY, "g_disk_kernedump(%s, %jd, %jd)", + g_trace(G_T_TOPOLOGY, "g_disk_kerneldump(%s, %jd, %jd)", gp->name, (intmax_t)gkd->offset, (intmax_t)gkd->length); if (dp->d_dump == NULL) { g_io_deliver(bp, ENODEV); return; } gkd->di.dumper = dp->d_dump; gkd->di.priv = dp; gkd->di.blocksize = dp->d_sectorsize; gkd->di.maxiosize = dp->d_maxsize; gkd->di.mediaoffset = gkd->offset; if ((gkd->offset + gkd->length) > dp->d_mediasize) gkd->length = dp->d_mediasize - gkd->offset; gkd->di.mediasize = gkd->length; g_io_deliver(bp, 0); } static void g_disk_setstate(struct bio *bp, struct g_disk_softc *sc) { const char *cmd; memcpy(&sc->state, bp->bio_data, sizeof(sc->state)); if (sc->led[0] != 0) { switch (sc->state) { case G_STATE_FAILED: cmd = "1"; break; case G_STATE_REBUILD: cmd = "f5"; break; case G_STATE_RESYNC: cmd = "f1"; break; default: cmd = "0"; break; } led_set(sc->led, cmd); } g_io_deliver(bp, 0); } static void g_disk_done(struct bio *bp) { struct bintime now; struct bio *bp2; struct g_disk_softc *sc; /* See "notes" for why we need a mutex here */ /* XXX: will witness accept a mix of Giant/unGiant drivers here ? */ bp2 = bp->bio_parent; sc = bp2->bio_to->private; bp->bio_completed = bp->bio_length - bp->bio_resid; binuptime(&now); mtx_lock(&sc->done_mtx); if (bp2->bio_error == 0) bp2->bio_error = bp->bio_error; bp2->bio_completed += bp->bio_completed; if ((bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) != 0) devstat_end_transaction_bio_bt(sc->dp->d_devstat, bp, &now); bp2->bio_inbed++; if (bp2->bio_children == bp2->bio_inbed) { mtx_unlock(&sc->done_mtx); bp2->bio_resid = bp2->bio_bcount - bp2->bio_completed; g_io_deliver(bp2, bp2->bio_error); } else mtx_unlock(&sc->done_mtx); g_destroy_bio(bp); } static void g_disk_done_single(struct bio *bp) { struct bintime now; struct g_disk_softc *sc; bp->bio_completed = bp->bio_length - bp->bio_resid; bp->bio_done = (void *)bp->bio_to; bp->bio_to = LIST_FIRST(&bp->bio_disk->d_geom->provider); if ((bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) != 0) { binuptime(&now); sc = bp->bio_to->private; mtx_lock(&sc->done_mtx); devstat_end_transaction_bio_bt(sc->dp->d_devstat, bp, &now); mtx_unlock(&sc->done_mtx); } g_io_deliver(bp, bp->bio_error); } static int g_disk_ioctl(struct g_provider *pp, u_long cmd, void * data, int fflag, struct thread *td) { struct disk *dp; struct g_disk_softc *sc; int error; sc = pp->private; dp = sc->dp; if (dp->d_ioctl == NULL) return (ENOIOCTL); error = dp->d_ioctl(dp, cmd, data, fflag, td); return (error); } static void g_disk_start(struct bio *bp) { struct bio *bp2, *bp3; struct disk *dp; struct g_disk_softc *sc; int error; off_t d_maxsize, off; sc = bp->bio_to->private; if (sc == NULL || (dp = sc->dp) == NULL || dp->d_destroyed) { g_io_deliver(bp, ENXIO); return; } error = EJUSTRETURN; switch(bp->bio_cmd) { case BIO_DELETE: if (!(dp->d_flags & DISKFLAG_CANDELETE)) { error = EOPNOTSUPP; break; } /* fall-through */ case BIO_READ: case BIO_WRITE: d_maxsize = (bp->bio_cmd == BIO_DELETE) ? dp->d_delmaxsize : dp->d_maxsize; if (bp->bio_length <= d_maxsize) { bp->bio_disk = dp; bp->bio_to = (void *)bp->bio_done; bp->bio_done = g_disk_done_single; bp->bio_pblkno = bp->bio_offset / dp->d_sectorsize; bp->bio_bcount = bp->bio_length; mtx_lock(&sc->start_mtx); devstat_start_transaction_bio(dp->d_devstat, bp); mtx_unlock(&sc->start_mtx); dp->d_strategy(bp); break; } off = 0; bp3 = NULL; bp2 = g_clone_bio(bp); if (bp2 == NULL) { error = ENOMEM; break; } do { bp2->bio_offset += off; bp2->bio_length -= off; if ((bp->bio_flags & BIO_UNMAPPED) == 0) { bp2->bio_data += off; } else { KASSERT((dp->d_flags & DISKFLAG_UNMAPPED_BIO) != 0, ("unmapped bio not supported by disk %s", dp->d_name)); bp2->bio_ma += off / PAGE_SIZE; bp2->bio_ma_offset += off; bp2->bio_ma_offset %= PAGE_SIZE; bp2->bio_ma_n -= off / PAGE_SIZE; } if (bp2->bio_length > d_maxsize) { /* * XXX: If we have a stripesize we should really * use it here. Care should be taken in the delete * case if this is done as deletes can be very * sensitive to size given how they are processed. */ bp2->bio_length = d_maxsize; if ((bp->bio_flags & BIO_UNMAPPED) != 0) { bp2->bio_ma_n = howmany( bp2->bio_ma_offset + bp2->bio_length, PAGE_SIZE); } off += d_maxsize; /* * To avoid a race, we need to grab the next bio * before we schedule this one. See "notes". */ bp3 = g_clone_bio(bp); if (bp3 == NULL) bp->bio_error = ENOMEM; } bp2->bio_done = g_disk_done; bp2->bio_pblkno = bp2->bio_offset / dp->d_sectorsize; bp2->bio_bcount = bp2->bio_length; bp2->bio_disk = dp; mtx_lock(&sc->start_mtx); devstat_start_transaction_bio(dp->d_devstat, bp2); mtx_unlock(&sc->start_mtx); dp->d_strategy(bp2); bp2 = bp3; bp3 = NULL; } while (bp2 != NULL); break; case BIO_GETATTR: /* Give the driver a chance to override */ if (dp->d_getattr != NULL) { if (bp->bio_disk == NULL) bp->bio_disk = dp; error = dp->d_getattr(bp); if (error != -1) break; error = EJUSTRETURN; } if (g_handleattr_int(bp, "GEOM::candelete", (dp->d_flags & DISKFLAG_CANDELETE) != 0)) break; else if (g_handleattr_int(bp, "GEOM::fwsectors", dp->d_fwsectors)) break; else if (g_handleattr_int(bp, "GEOM::fwheads", dp->d_fwheads)) break; else if (g_handleattr_off_t(bp, "GEOM::frontstuff", 0)) break; else if (g_handleattr_str(bp, "GEOM::ident", dp->d_ident)) break; else if (g_handleattr_uint16_t(bp, "GEOM::hba_vendor", dp->d_hba_vendor)) break; else if (g_handleattr_uint16_t(bp, "GEOM::hba_device", dp->d_hba_device)) break; else if (g_handleattr_uint16_t(bp, "GEOM::hba_subvendor", dp->d_hba_subvendor)) break; else if (g_handleattr_uint16_t(bp, "GEOM::hba_subdevice", dp->d_hba_subdevice)) break; else if (!strcmp(bp->bio_attribute, "GEOM::kerneldump")) g_disk_kerneldump(bp, dp); else if (!strcmp(bp->bio_attribute, "GEOM::setstate")) g_disk_setstate(bp, sc); else if (g_handleattr_uint16_t(bp, "GEOM::rotation_rate", dp->d_rotation_rate)) break; else error = ENOIOCTL; break; case BIO_FLUSH: g_trace(G_T_BIO, "g_disk_flushcache(%s)", bp->bio_to->name); if (!(dp->d_flags & DISKFLAG_CANFLUSHCACHE)) { error = EOPNOTSUPP; break; } bp->bio_disk = dp; bp->bio_to = (void *)bp->bio_done; bp->bio_done = g_disk_done_single; dp->d_strategy(bp); break; default: error = EOPNOTSUPP; break; } if (error != EJUSTRETURN) g_io_deliver(bp, error); return; } static void g_disk_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp) { struct bio *bp; struct disk *dp; struct g_disk_softc *sc; char *buf; int res = 0; sc = gp->softc; if (sc == NULL || (dp = sc->dp) == NULL) return; if (indent == NULL) { sbuf_printf(sb, " hd %u", dp->d_fwheads); sbuf_printf(sb, " sc %u", dp->d_fwsectors); return; } if (pp != NULL) { sbuf_printf(sb, "%s%u\n", indent, dp->d_fwheads); sbuf_printf(sb, "%s%u\n", indent, dp->d_fwsectors); if (dp->d_getattr != NULL) { buf = g_malloc(DISK_IDENT_SIZE, M_WAITOK); bp = g_alloc_bio(); bp->bio_disk = dp; bp->bio_attribute = "GEOM::ident"; bp->bio_length = DISK_IDENT_SIZE; bp->bio_data = buf; res = dp->d_getattr(bp); sbuf_printf(sb, "%s", indent); g_conf_printf_escaped(sb, "%s", res == 0 ? buf: dp->d_ident); sbuf_printf(sb, "\n"); bp->bio_attribute = "GEOM::lunid"; bp->bio_length = DISK_IDENT_SIZE; bp->bio_data = buf; if (dp->d_getattr(bp) == 0) { sbuf_printf(sb, "%s", indent); g_conf_printf_escaped(sb, "%s", buf); sbuf_printf(sb, "\n"); } bp->bio_attribute = "GEOM::lunname"; bp->bio_length = DISK_IDENT_SIZE; bp->bio_data = buf; if (dp->d_getattr(bp) == 0) { sbuf_printf(sb, "%s", indent); g_conf_printf_escaped(sb, "%s", buf); sbuf_printf(sb, "\n"); } g_destroy_bio(bp); g_free(buf); } else { sbuf_printf(sb, "%s", indent); g_conf_printf_escaped(sb, "%s", dp->d_ident); sbuf_printf(sb, "\n"); } sbuf_printf(sb, "%s", indent); g_conf_printf_escaped(sb, "%s", dp->d_descr); sbuf_printf(sb, "\n"); } } static void g_disk_resize(void *ptr, int flag) { struct disk *dp; struct g_geom *gp; struct g_provider *pp; if (flag == EV_CANCEL) return; g_topology_assert(); dp = ptr; gp = dp->d_geom; if (dp->d_destroyed || gp == NULL) return; LIST_FOREACH(pp, &gp->provider, provider) { if (pp->sectorsize != 0 && pp->sectorsize != dp->d_sectorsize) g_wither_provider(pp, ENXIO); else g_resize_provider(pp, dp->d_mediasize); } } static void g_disk_create(void *arg, int flag) { struct g_geom *gp; struct g_provider *pp; struct disk *dp; struct g_disk_softc *sc; char tmpstr[80]; if (flag == EV_CANCEL) return; g_topology_assert(); dp = arg; sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO); mtx_init(&sc->start_mtx, "g_disk_start", NULL, MTX_DEF); mtx_init(&sc->done_mtx, "g_disk_done", NULL, MTX_DEF); sc->dp = dp; gp = g_new_geomf(&g_disk_class, "%s%d", dp->d_name, dp->d_unit); gp->softc = sc; pp = g_new_providerf(gp, "%s", gp->name); devstat_remove_entry(pp->stat); pp->stat = NULL; dp->d_devstat->id = pp; pp->mediasize = dp->d_mediasize; pp->sectorsize = dp->d_sectorsize; pp->stripeoffset = dp->d_stripeoffset; pp->stripesize = dp->d_stripesize; if ((dp->d_flags & DISKFLAG_UNMAPPED_BIO) != 0) pp->flags |= G_PF_ACCEPT_UNMAPPED; if ((dp->d_flags & DISKFLAG_DIRECT_COMPLETION) != 0) pp->flags |= G_PF_DIRECT_SEND; pp->flags |= G_PF_DIRECT_RECEIVE; if (bootverbose) printf("GEOM: new disk %s\n", gp->name); sysctl_ctx_init(&sc->sysctl_ctx); snprintf(tmpstr, sizeof(tmpstr), "GEOM disk %s", gp->name); sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx, SYSCTL_STATIC_CHILDREN(_kern_geom_disk), OID_AUTO, gp->name, CTLFLAG_RD, 0, tmpstr); if (sc->sysctl_tree != NULL) { snprintf(tmpstr, sizeof(tmpstr), "kern.geom.disk.%s.led", gp->name); TUNABLE_STR_FETCH(tmpstr, sc->led, sizeof(sc->led)); SYSCTL_ADD_STRING(&sc->sysctl_ctx, SYSCTL_CHILDREN(sc->sysctl_tree), OID_AUTO, "led", CTLFLAG_RW | CTLFLAG_TUN, sc->led, sizeof(sc->led), "LED name"); } pp->private = sc; dp->d_geom = gp; g_error_provider(pp, 0); } /* * We get this callback after all of the consumers have gone away, and just * before the provider is freed. If the disk driver provided a d_gone * callback, let them know that it is okay to free resources -- they won't * be getting any more accesses from GEOM. */ static void g_disk_providergone(struct g_provider *pp) { struct disk *dp; struct g_disk_softc *sc; sc = (struct g_disk_softc *)pp->private; dp = sc->dp; if (dp != NULL && dp->d_gone != NULL) dp->d_gone(dp); if (sc->sysctl_tree != NULL) { sysctl_ctx_free(&sc->sysctl_ctx); sc->sysctl_tree = NULL; } if (sc->led[0] != 0) { led_set(sc->led, "0"); sc->led[0] = 0; } pp->private = NULL; pp->geom->softc = NULL; mtx_destroy(&sc->done_mtx); mtx_destroy(&sc->start_mtx); g_free(sc); } static void g_disk_destroy(void *ptr, int flag) { struct disk *dp; struct g_geom *gp; struct g_disk_softc *sc; g_topology_assert(); dp = ptr; gp = dp->d_geom; if (gp != NULL) { sc = gp->softc; if (sc != NULL) sc->dp = NULL; dp->d_geom = NULL; g_wither_geom(gp, ENXIO); } g_free(dp); } /* * We only allow printable characters in disk ident, * the rest is converted to 'x'. */ static void g_disk_ident_adjust(char *ident, size_t size) { char *p, tmp[4], newid[DISK_IDENT_SIZE]; newid[0] = '\0'; for (p = ident; *p != '\0'; p++) { if (isprint(*p)) { tmp[0] = *p; tmp[1] = '\0'; } else { snprintf(tmp, sizeof(tmp), "x%02hhx", *(unsigned char *)p); } if (strlcat(newid, tmp, sizeof(newid)) >= sizeof(newid)) break; } bzero(ident, size); strlcpy(ident, newid, size); } struct disk * disk_alloc(void) { return (g_malloc(sizeof(struct disk), M_WAITOK | M_ZERO)); } void disk_create(struct disk *dp, int version) { if (version != DISK_VERSION) { printf("WARNING: Attempt to add disk %s%d %s", dp->d_name, dp->d_unit, " using incompatible ABI version of disk(9)\n"); printf("WARNING: Ignoring disk %s%d\n", dp->d_name, dp->d_unit); return; } if (dp->d_flags & DISKFLAG_RESERVED) { printf("WARNING: Attempt to add non-MPSAFE disk %s%d\n", dp->d_name, dp->d_unit); printf("WARNING: Ignoring disk %s%d\n", dp->d_name, dp->d_unit); return; } KASSERT(dp->d_strategy != NULL, ("disk_create need d_strategy")); KASSERT(dp->d_name != NULL, ("disk_create need d_name")); KASSERT(*dp->d_name != 0, ("disk_create need d_name")); KASSERT(strlen(dp->d_name) < SPECNAMELEN - 4, ("disk name too long")); if (dp->d_devstat == NULL) dp->d_devstat = devstat_new_entry(dp->d_name, dp->d_unit, dp->d_sectorsize, DEVSTAT_ALL_SUPPORTED, DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); dp->d_geom = NULL; g_disk_ident_adjust(dp->d_ident, sizeof(dp->d_ident)); g_post_event(g_disk_create, dp, M_WAITOK, dp, NULL); } void disk_destroy(struct disk *dp) { g_cancel_event(dp); dp->d_destroyed = 1; if (dp->d_devstat != NULL) devstat_remove_entry(dp->d_devstat); g_post_event(g_disk_destroy, dp, M_WAITOK, NULL); } void disk_gone(struct disk *dp) { struct g_geom *gp; struct g_provider *pp; gp = dp->d_geom; if (gp != NULL) { pp = LIST_FIRST(&gp->provider); if (pp != NULL) { KASSERT(LIST_NEXT(pp, provider) == NULL, ("geom %p has more than one provider", gp)); g_wither_provider(pp, ENXIO); } } } void disk_attr_changed(struct disk *dp, const char *attr, int flag) { struct g_geom *gp; struct g_provider *pp; gp = dp->d_geom; if (gp != NULL) LIST_FOREACH(pp, &gp->provider, provider) (void)g_attr_changed(pp, attr, flag); } void disk_media_changed(struct disk *dp, int flag) { struct g_geom *gp; struct g_provider *pp; gp = dp->d_geom; if (gp != NULL) { pp = LIST_FIRST(&gp->provider); if (pp != NULL) { KASSERT(LIST_NEXT(pp, provider) == NULL, ("geom %p has more than one provider", gp)); g_media_changed(pp, flag); } } } void disk_media_gone(struct disk *dp, int flag) { struct g_geom *gp; struct g_provider *pp; gp = dp->d_geom; if (gp != NULL) { pp = LIST_FIRST(&gp->provider); if (pp != NULL) { KASSERT(LIST_NEXT(pp, provider) == NULL, ("geom %p has more than one provider", gp)); g_media_gone(pp, flag); } } } int disk_resize(struct disk *dp, int flag) { if (dp->d_destroyed || dp->d_geom == NULL) return (0); return (g_post_event(g_disk_resize, dp, flag, NULL)); } static void g_kern_disks(void *p, int flag __unused) { struct sbuf *sb; struct g_geom *gp; char *sp; sb = p; sp = ""; g_topology_assert(); LIST_FOREACH(gp, &g_disk_class.geom, geom) { sbuf_printf(sb, "%s%s", sp, gp->name); sp = " "; } sbuf_finish(sb); } static int sysctl_disks(SYSCTL_HANDLER_ARGS) { int error; struct sbuf *sb; sb = sbuf_new_auto(); g_waitfor_event(g_kern_disks, sb, M_WAITOK, NULL); error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); sbuf_delete(sb); return error; } SYSCTL_PROC(_kern, OID_AUTO, disks, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_disks, "A", "names of available disks");