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author | mjacob <mjacob@FreeBSD.org> | 2007-02-27 04:01:58 +0000 |
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committer | mjacob <mjacob@FreeBSD.org> | 2007-02-27 04:01:58 +0000 |
commit | 05b92097cb751ac3e6ba126eed272f954f9c7210 (patch) | |
tree | 3740487c6f9b60010343610543a779a7e9a63d31 /sbin | |
parent | 502eb2ec0e1f3a8e4b78b14ccfaad6822c33bbb6 (diff) | |
download | FreeBSD-src-05b92097cb751ac3e6ba126eed272f954f9c7210.zip FreeBSD-src-05b92097cb751ac3e6ba126eed272f954f9c7210.tar.gz |
First cut at GEOM based multipath. This is an active/passive{/passive...}
arrangement that has no intrinsic internal knowledge of whether devices
it is given are truly multipath devices. As such, this is a simplistic
approach, but still a useful one.
The basic approach is to (at present- this will change soon) use camcontrol
to find likely identical devices and and label the trailing sector of the
first one. This label contains both a full UUID and a name. The name is
what is presented in /dev/multipath, but the UUID is used as a true
distinguishor at g_taste time, thus making sure we don't have chaos
on a shared SAN where everyone names their data multipath as "Fred".
The first of N identical devices (and N *may* be 1!) becomes the active
path until a BIO request is failed with EIO or ENXIO. When this occurs,
the active disk is ripped away and the next in a list is picked to
(retry and) continue with.
During g_taste events new disks that meet the match criteria for existing
multipath geoms get added to the tail end of the list.
Thus, this active/passive setup actually does work for devices which
go away and come back, as do (now) mpt(4) and isp(4) SAN based disks.
There is still a lot to do to improve this- like about 5 of the 12
recommendations I've received about it, but it's been functional enough
for a while that it deserves a broader test base.
Reviewed by: pjd
Sponsored by: IronPort Systems
MFC: 2 months
Diffstat (limited to 'sbin')
-rw-r--r-- | sbin/geom/class/Makefile | 1 | ||||
-rw-r--r-- | sbin/geom/class/multipath/Makefile | 10 | ||||
-rw-r--r-- | sbin/geom/class/multipath/geom_multipath.c | 230 |
3 files changed, 241 insertions, 0 deletions
diff --git a/sbin/geom/class/Makefile b/sbin/geom/class/Makefile index 7adfe5e..f52695b 100644 --- a/sbin/geom/class/Makefile +++ b/sbin/geom/class/Makefile @@ -10,6 +10,7 @@ SUBDIR+=eli SUBDIR+=journal SUBDIR+=label SUBDIR+=mirror +SUBDIR+=multipath SUBDIR+=nop SUBDIR+=raid3 SUBDIR+=shsec diff --git a/sbin/geom/class/multipath/Makefile b/sbin/geom/class/multipath/Makefile new file mode 100644 index 0000000..7b418e1 --- /dev/null +++ b/sbin/geom/class/multipath/Makefile @@ -0,0 +1,10 @@ +# $FreeBSD$ + +.PATH: ${.CURDIR}/../../misc +CLASS= multipath +NO_MAN=true + + +.include <bsd.lib.mk> + +CFLAGS+= -I${.CURDIR}/../../../../sys diff --git a/sbin/geom/class/multipath/geom_multipath.c b/sbin/geom/class/multipath/geom_multipath.c new file mode 100644 index 0000000..d729af7 --- /dev/null +++ b/sbin/geom/class/multipath/geom_multipath.c @@ -0,0 +1,230 @@ +/*- + * Copyright (c) 2006 Mathew Jacob <mjacob@FreeBSD.org> + * All rights reserved. + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); +#include <sys/param.h> +#include <errno.h> +#include <paths.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <strings.h> +#include <assert.h> +#include <libgeom.h> +#include <uuid.h> +#include <geom/multipath/g_multipath.h> + +#include "core/geom.h" +#include "misc/subr.h" + +uint32_t lib_version = G_LIB_VERSION; +uint32_t version = G_MULTIPATH_VERSION; + +static void mp_main(struct gctl_req *, unsigned int); +static void mp_label(struct gctl_req *); +static void mp_clear(struct gctl_req *); + +struct g_command class_commands[] = { + { + "label", G_FLAG_VERBOSE | G_FLAG_LOADKLD, mp_main, G_NULL_OPTS, + "[-v] name prov ..." + }, + { + "clear", G_FLAG_VERBOSE, mp_main, G_NULL_OPTS, + "[-v] prov ..." + }, + G_CMD_SENTINEL +}; + +static void +mp_main(struct gctl_req *req, unsigned int flags __unused) +{ + const char *name; + + name = gctl_get_ascii(req, "verb"); + if (name == NULL) { + gctl_error(req, "No '%s' argument.", "verb"); + return; + } + if (strcmp(name, "label") == 0) { + mp_label(req); + } else if (strcmp(name, "clear") == 0) { + mp_clear(req); + } else { + gctl_error(req, "Unknown command: %s.", name); + } +} + +static void +mp_label(struct gctl_req *req) +{ + struct g_multipath_metadata md; + off_t disksiz = 0, msize; + uint8_t *sector; + char *ptr; + uuid_t uuid; + uint32_t secsize = 0, ssize, status; + const char *name; + int error, i, nargs; + + nargs = gctl_get_int(req, "nargs"); + if (nargs < 2) { + gctl_error(req, "wrong number of arguments."); + return; + } + + /* + * First, check each provider to make sure it's the same size. + * This also gets us our size and sectorsize for the metadata. + */ + for (i = 1; i < nargs; i++) { + name = gctl_get_ascii(req, "arg%d", i); + msize = g_get_mediasize(name); + ssize = g_get_sectorsize(name); + if (msize == 0 || ssize == 0) { + gctl_error(req, "cannot get information about %s: %s.", + name, strerror(errno)); + return; + } + if (i == 1) { + secsize = ssize; + disksiz = msize; + } else { + if (secsize != ssize) { + gctl_error(req, "%s sector size %u different.", + name, ssize); + return; + } + if (disksiz != msize) { + gctl_error(req, "%s media size %ju different.", + name, (intmax_t)msize); + return; + } + } + + } + + /* + * Allocate a sector to write as metadata. + */ + sector = malloc(secsize); + if (sector == NULL) { + gctl_error(req, "unable to allocate metadata buffer"); + return; + } + memset(sector, 0, secsize); + + /* + * Generate metadata. + */ + strlcpy(md.md_magic, G_MULTIPATH_MAGIC, sizeof(md.md_magic)); + md.md_version = G_MULTIPATH_VERSION; + name = gctl_get_ascii(req, "arg0"); + strlcpy(md.md_name, name, sizeof(md.md_name)); + md.md_size = disksiz; + md.md_sectorsize = secsize; + uuid_create(&uuid, &status); + if (status != uuid_s_ok) { + gctl_error(req, "cannot create a UUID."); + return; + } + uuid_to_string(&uuid, &ptr, &status); + if (status != uuid_s_ok) { + gctl_error(req, "cannot stringify a UUID."); + return; + } + strlcpy(md.md_uuid, ptr, sizeof (md.md_uuid)); + free(ptr); + + /* + * Clear last sector first for each provider to spoil anything extant + */ + for (i = 1; i < nargs; i++) { + name = gctl_get_ascii(req, "arg%d", i); + error = g_metadata_clear(name, NULL); + if (error != 0) { + gctl_error(req, "cannot clear metadata on %s: %s.", + name, strerror(error)); + return; + } + } + + multipath_metadata_encode(&md, sector); + + /* + * Ok, store metadata. + */ + for (i = 1; i < nargs; i++) { + name = gctl_get_ascii(req, "arg%d", i); + error = g_metadata_store(name, sector, secsize); + if (error != 0) { + fprintf(stderr, "Can't store metadata on %s: %s.\n", + name, strerror(error)); + goto fail; + } + } + return; + +fail: + /* + * Clear last sector first for each provider to spoil anything extant + */ + for (i = 1; i < nargs; i++) { + name = gctl_get_ascii(req, "arg%d", i); + error = g_metadata_clear(name, NULL); + if (error != 0) { + gctl_error(req, "cannot clear metadata on %s: %s.", + name, strerror(error)); + continue; + } + } +} + +static void +mp_clear(struct gctl_req *req) +{ + const char *name; + int error, i, nargs; + + nargs = gctl_get_int(req, "nargs"); + if (nargs < 1) { + gctl_error(req, "Too few arguments."); + return; + } + + for (i = 0; i < nargs; i++) { + name = gctl_get_ascii(req, "arg%d", i); + error = g_metadata_clear(name, G_MULTIPATH_MAGIC); + if (error != 0) { + fprintf(stderr, "Can't clear metadata on %s: %s.\n", + name, strerror(error)); + gctl_error(req, "Not fully done."); + continue; + } + } +} |