Re: [libvirt] [PATCH 1/1] Add SCSI pool support.

It does not attempt to add a volume if it cannot find a stable path for a particular LU, for example, if the user specifies a target path by-id and the LU is one path of a multipath device.

diff --git a/src/storage_backend_scsi.c b/src/storage_backend_scsi.c new file mode 100644 index 0000000..62c05ae +static int +processLU(virConnectPtr conn, + virStoragePoolObjPtr pool, + uint32_t host, + uint32_t bus, + uint32_t target, + uint32_t lun) +{ + char *type_path = NULL; + int retval = 0; + int device_type; + char *block_device = NULL; + + VIR_DEBUG(_("Processing LU %u:%u:%u:%u"), + host, bus, target, lun); + + if (getDeviceType(conn, host, bus, target, lun, &device_type) < 0) { + virStorageReportError(conn, VIR_ERR_INTERNAL_ERROR, + _("Failed to determine if %u:%u:%u:%u is a Direct-Access LUN"), + host, bus, target, lun); + retval = -1; + goto out; + } + + /* We don't use anything except Direct-Access devices, but finding + * one isn't an error, either. */ + if (device_type != 0) { + retval = 0; + goto out; + }

+ + VIR_DEBUG(_("%u:%u:%u:%u is a Direct-Access LUN"), + host, bus, target, lun); + + if (getBlockDevice(conn, host, bus, target, lun, &block_device) < 0) { + goto out; + } + + if (virStorageBackendSCSINewLun(conn, pool, + host, bus, target, lun, + block_device) < 0) { + VIR_DEBUG(_("Failed to create new storage volume for %u:%u:%u:%u"), + host, bus, target, lun); + retval = -1; + goto out; + } + + VIR_DEBUG(_("Created new storage volume for %u:%u:%u:%u successfully"), + host, bus, target, lun); + + VIR_FREE(type_path); + +out: + return retval; +} + + +static int +virStorageBackendSCSIFindLUs(virConnectPtr conn, + virStoragePoolObjPtr pool, + uint32_t scanhost, + uint32_t scanbus, + uint32_t scantarget) +{ + int retval = 0; + uint32_t host, bus, target, lun; + char *target_path = NULL; + DIR *targetdir = NULL; + struct dirent *lun_dirent = NULL; + + VIR_DEBUG(_("Discovering LUs on host %u bus %u target %u"), + scanhost, scanbus, scantarget); + + if (virAsprintf(&target_path, "/sys/bus/scsi/devices/target%u:%u:%u", + scanhost, scanbus, scantarget) < 0) { + virReportOOMError(conn); + goto out; + }

+ + targetdir = opendir(target_path); + + if (targetdir == NULL) { + virReportSystemError(conn, errno, + _("Failed to opendir path '%s'"), target_path); + retval = -1; + goto out; + } + + while ((lun_dirent = readdir(targetdir))) { + if (sscanf(lun_dirent->d_name, "%u:%u:%u:%u\n", + &host, &bus, &target, &lun) != 4) { + continue; + } + + VIR_DEBUG(_("Found LU '%s'"), lun_dirent->d_name); + + processLU(conn, pool, host, bus, target, lun); + } + + closedir(targetdir); + +out: + VIR_FREE(target_path); + return retval; +} + + +int +virStorageBackendSCSIFindTargets(virConnectPtr conn, + virStoragePoolObjPtr pool, + const char *sysfs_path, + const char *pattern) +{ + int retval = 0; + uint32_t host, bus, target; + DIR *sysdir = NULL; + struct dirent *dirent = NULL; + + VIR_DEBUG(_("Discovering targets in '%s'"), sysfs_path); + + sysdir = opendir(sysfs_path); + + if (sysdir == NULL) { + virReportSystemError(conn, errno, + _("Failed to opendir path '%s'"), sysfs_path); + retval = -1; + goto out; + } + + while ((dirent = readdir(sysdir))) { + if (STREQLEN(dirent->d_name, pattern, strlen(pattern))) { + if (sscanf(dirent->d_name, + "target%u:%u:%u", &host, &bus, &target) != 3) { + VIR_DEBUG(_("Failed to parse target '%s'"), dirent->d_name); + retval = -1; + break; + } + virStorageBackendSCSIFindLUs(conn, pool, host, bus, target); + } + } + + closedir(sysdir); +out: + return retval; +} + + +static int +virStorageBackendSCSIRefreshPool(virConnectPtr conn, + virStoragePoolObjPtr pool) +{ + char targetN[64]; + int retval = 0; + uint32_t host; + + pool->def->allocation = pool->def->capacity = pool->def->available = 0; + + virStorageBackendWaitForDevices(conn); + + if (sscanf(pool->def->source.adapter, "host%u", &host) != 1) { + VIR_DEBUG(_("Failed to get host number from '%s'"), pool->def->source.adapter); + retval = -1; + goto out; + } + + VIR_DEBUG(_("Scanning host%u"), host); + + snprintf(targetN, sizeof(targetN), "target%u", host); + + virStorageBackendSCSIFindTargets(conn, pool, "/sys/bus/scsi/devices", targetN);