/* * storage_backend_mpath.c: storage backend for multipath handling * * Copyright (C) 2009-2010 Red Hat, Inc. * Copyright (C) 2009-2008 Dave Allan * * 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, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Author: Dave Allan */ #include #include #include #include #include #include #include "virterror_internal.h" #include "storage_conf.h" #include "storage_backend.h" #include "memory.h" #include "logging.h" #include "files.h" #define VIR_FROM_THIS VIR_FROM_STORAGE static int virStorageBackendMpathUpdateVolTargetInfo(virStorageVolTargetPtr target, unsigned long long *allocation, unsigned long long *capacity) { int ret = -1; int fdret, fd = -1; if ((fdret = virStorageBackendVolOpen(target->path)) < 0) goto out; fd = fdret; if (virStorageBackendUpdateVolTargetInfoFD(target, fd, allocation, capacity) < 0) goto out; if (virStorageBackendDetectBlockVolFormatFD(target, fd) < 0) goto out; ret = 0; out: VIR_FORCE_CLOSE(fd); return ret; } static int virStorageBackendMpathNewVol(virStoragePoolObjPtr pool, const int devnum, const char *dev) { virStorageVolDefPtr vol; int ret = -1; if (VIR_ALLOC(vol) < 0) { virReportOOMError(); goto cleanup; } vol->type = VIR_STORAGE_VOL_BLOCK; if (virAsprintf(&(vol->name), "dm-%u", devnum) < 0) { virReportOOMError(); goto cleanup; } if (virAsprintf(&vol->target.path, "/dev/%s", dev) < 0) { virReportOOMError(); goto cleanup; } if (virStorageBackendMpathUpdateVolTargetInfo(&vol->target, &vol->allocation, &vol->capacity) < 0) { goto cleanup; } /* XXX should use logical unit's UUID instead */ vol->key = strdup(vol->target.path); if (vol->key == NULL) { virReportOOMError(); goto cleanup; } if (VIR_REALLOC_N(pool->volumes.objs, pool->volumes.count + 1) < 0) { virReportOOMError(); goto cleanup; } pool->volumes.objs[pool->volumes.count++] = vol; pool->def->capacity += vol->capacity; pool->def->allocation += vol->allocation; ret = 0; cleanup: if (ret != 0) virStorageVolDefFree(vol); return ret; } static int virStorageBackendIsMultipath(const char *devname) { int ret = 0; struct dm_task *dmt = NULL; void *next = NULL; uint64_t start, length; char *target_type = NULL; char *params = NULL; dmt = dm_task_create(DM_DEVICE_TABLE); if (dmt == NULL) { ret = -1; goto out; } if (dm_task_set_name(dmt, devname) == 0) { ret = -1; goto out; } dm_task_no_open_count(dmt); if (!dm_task_run(dmt)) { ret = -1; goto out; } dm_get_next_target(dmt, next, &start, &length, &target_type, ¶ms); if (target_type == NULL) { ret = -1; goto out; } if (STREQ(target_type, "multipath")) { ret = 1; } out: if (dmt != NULL) { dm_task_destroy(dmt); } return ret; } static int virStorageBackendGetMinorNumber(const char *devname, uint32_t *minor) { int ret = -1; struct dm_task *dmt; struct dm_info info; if (!(dmt = dm_task_create(DM_DEVICE_INFO))) { goto out; } if (!dm_task_set_name(dmt, devname)) { goto out; } if (!dm_task_run(dmt)) { goto out; } if (!dm_task_get_info(dmt, &info)) { goto out; } *minor = info.minor; ret = 0; out: if (dmt != NULL) dm_task_destroy(dmt); return ret; } static int virStorageBackendCreateVols(virStoragePoolObjPtr pool, struct dm_names *names) { int retval = -1, is_mpath = 0; char *map_device = NULL; uint32_t minor = -1; uint32_t next; do { is_mpath = virStorageBackendIsMultipath(names->name); if (is_mpath < 0) { goto out; } if (is_mpath == 1) { if (virAsprintf(&map_device, "mapper/%s", names->name) < 0) { virReportOOMError(); goto out; } if (virStorageBackendGetMinorNumber(names->name, &minor) < 0) { virStorageReportError(VIR_ERR_INTERNAL_ERROR, _("Failed to get %s minor number"), names->name); goto out; } if (virStorageBackendMpathNewVol(pool, minor, map_device) < 0) { goto out; } VIR_FREE(map_device); } /* Given the way libdevmapper returns its data, I don't see * any way to avoid this series of casts. */ next = names->next; names = (struct dm_names *)(((char *)names) + next); } while (next); retval = 0; out: return retval; } static int virStorageBackendGetMaps(virStoragePoolObjPtr pool) { int retval = 0; struct dm_task *dmt = NULL; struct dm_names *names = NULL; if (!(dmt = dm_task_create(DM_DEVICE_LIST))) { retval = 1; goto out; } dm_task_no_open_count(dmt); if (!dm_task_run(dmt)) { retval = 1; goto out; } if (!(names = dm_task_get_names(dmt))) { retval = 1; goto out; } if (!names->dev) { /* No devices found */ goto out; } virStorageBackendCreateVols(pool, names); out: if (dmt != NULL) { dm_task_destroy (dmt); } return retval; } static int virStorageBackendMpathCheckPool(virConnectPtr conn ATTRIBUTE_UNUSED, virStoragePoolObjPtr pool ATTRIBUTE_UNUSED, bool *isActive) { const char *path = "/dev/mpath"; *isActive = false; if (access(path, F_OK) == 0) *isActive = true; return 0; } static int virStorageBackendMpathRefreshPool(virConnectPtr conn ATTRIBUTE_UNUSED, virStoragePoolObjPtr pool) { int retval = 0; VIR_DEBUG("conn=%p, pool=%p", conn, pool); pool->def->allocation = pool->def->capacity = pool->def->available = 0; virFileWaitForDevices(); virStorageBackendGetMaps(pool); return retval; } virStorageBackend virStorageBackendMpath = { .type = VIR_STORAGE_POOL_MPATH, .checkPool = virStorageBackendMpathCheckPool, .refreshPool = virStorageBackendMpathRefreshPool, };