libvirt/src/storage/parthelper.c
John Ferlan 8cdff0b93f storage: Fix virStorageBackendDiskDeleteVol for device mapper
Commit id 'df1011ca8' modified virStorageBackendDiskDeleteVol to use
"dmsetup remove --force" to remove the volume, but left things in an
inconsistent state since the partition still existed on the disk and
only the device mapper device (/dev/dm-#) was removed.

Prior to commit '1895b421' (or '1ffd82bb' and '471e1c4e'), this could
go unnoticed since virStorageBackendDiskRefreshPool wasn't called.
However, the pool would be unusable since the /dev/dm-# device would
be removed even though the partition was not removed unless a multipathd
restart reset the link. That would of course make the volume appear again
in the pool after a refresh or pool start after libvirt reload.

This patch removes the 'dmsetup' logic and re-implements the partition
deletion logic for device mapper devices. The removal of the partition
via 'parted rm --script #' will cause udev device change logic to allow
multipathd to handle removing the dm-* device associated with the partition.
2016-05-11 09:23:31 -04:00

185 lines
6.1 KiB
C

/*
* parthelper.c: Helper program to talk to parted with.
*
* This helper exists because parted is GPLv3+, while libvirt is LGPLv2+.
* Thus we can't link to parted in libvirt.so without the combined work
* being GPLv3+. Thus we separate via an external command. NB, this source
* code is still LGPLv2+, but the binary helper is effectively GPLv3+
*
* The existing 'parted' command line tool is also incredibly hard to parse
* in a reliable fashion if merely after a list of partitions & sizes,
* though it is fine for creating partitions.
*
* Copyright (C) 2007-2008, 2010, 2013, 2016 Red Hat, Inc.
* Copyright (C) 2007-2008 Daniel P. Berrange
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
* Author: Daniel P. Berrange <berrange@redhat.com>
*/
#include <config.h>
#include <parted/parted.h>
#include <stdio.h>
#include <string.h>
#include <libdevmapper.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "virutil.h"
#include "virfile.h"
#include "c-ctype.h"
#include "virstring.h"
#include "virgettext.h"
/* we don't need to include the full internal.h just for this */
#define STREQ(a, b) (strcmp(a, b) == 0)
/* Make the comparisons below fail if your parted headers
are so old that they lack the definition. */
#ifndef PED_PARTITION_PROTECTED
# define PED_PARTITION_PROTECTED 0
#endif
enum diskCommand {
DISK_LAYOUT = 0,
DISK_GEOMETRY
};
int main(int argc, char **argv)
{
PedDevice *dev;
PedDisk *disk;
PedPartition *part;
int cmd = DISK_LAYOUT;
const char *path;
char *canonical_path;
const char *partsep;
bool devmap_partsep = false;
if (virGettextInitialize() < 0)
exit(EXIT_FAILURE);
if (argc == 3 && STREQ(argv[2], "-g")) {
cmd = DISK_GEOMETRY;
} else if (argc == 3 && STREQ(argv[2], "-p")) {
devmap_partsep = true;
} else if (argc != 2) {
fprintf(stderr, _("syntax: %s DEVICE [-g]|[-p]\n"), argv[0]);
return 1;
}
/* NB: Changes to the following algorithm will need corresponding
* changes to virStorageBackendDiskDeleteVol */
path = argv[1];
if (virIsDevMapperDevice(path)) {
/* If the path ends with a number or we explicitly request it for
* path, then append the "p" partition separator. Otherwise, if
* the path ends with a letter already, then no need for a separator.
*/
if (c_isdigit(path[strlen(path)-1]) || devmap_partsep)
partsep = "p";
else
partsep = "";
if (VIR_STRDUP_QUIET(canonical_path, path) < 0)
return 2;
} else {
if (virFileResolveLink(path, &canonical_path) != 0)
return 2;
partsep = *canonical_path &&
c_isdigit(canonical_path[strlen(canonical_path)-1]) ? "p" : "";
}
if ((dev = ped_device_get(path)) == NULL) {
fprintf(stderr, _("unable to access device %s\n"), path);
return 2;
}
/* return the geometry of the disk and then exit */
if (cmd == DISK_GEOMETRY) {
printf("%d%c%d%c%d%c",
dev->hw_geom.cylinders, '\0',
dev->hw_geom.heads, '\0',
dev->hw_geom.sectors, '\0');
return 0;
}
if ((disk = ped_disk_new(dev)) == NULL) {
fprintf(stderr, _("unable to access disk %s\n"), argv[1]);
return 2;
}
/* Get the first partition, and then iterate over all */
part = ped_disk_next_partition(disk, NULL);
while (part) {
const char *type;
const char *content;
if (part->type & PED_PARTITION_LOGICAL) {
type = "logical";
if (part->type & PED_PARTITION_FREESPACE)
content = "free";
else if (part->type & PED_PARTITION_METADATA)
content = "metadata";
/* coverity[dead_error_condition] - not true if defined */
else if (part->type & PED_PARTITION_PROTECTED)
content = "protected";
else
content = "data";
} else if (part->type == PED_PARTITION_EXTENDED) {
type = "extended";
content = "metadata";
} else {
type = "normal";
if (part->type & PED_PARTITION_FREESPACE)
content = "free";
else if (part->type & PED_PARTITION_METADATA)
content = "metadata";
/* coverity[dead_error_condition] - not true if defined */
else if (part->type & PED_PARTITION_PROTECTED)
content = "protected";
else
content = "data";
}
/* We do +1 on geom.end, because we want end of the last sector
* in bytes, not the last sector number
*/
if (part->num != -1) {
printf("%s%s%d%c%s%c%s%c%llu%c%llu%c%llu%c",
canonical_path, partsep,
part->num, '\0',
type, '\0',
content, '\0',
part->geom.start * dev->sector_size, '\0',
(part->geom.end + 1) * dev->sector_size, '\0',
part->geom.length * dev->sector_size, '\0');
} else {
printf("%s%c%s%c%s%c%llu%c%llu%c%llu%c",
"-", '\0',
type, '\0',
content, '\0',
part->geom.start * dev->sector_size, '\0',
(part->geom.end + 1) * dev->sector_size, '\0',
part->geom.length * dev->sector_size, '\0');
}
part = ped_disk_next_partition(disk, part);
}
return 0;
}