[libvirt] [PATCH 03/11] storage: Add partition type checks for BLKID probing

A device may be formatted using some sort of disk partition format type. We can check that using the blkid_ API's as well - so alter the logic to allow checking the device for both a filesystem and a disk partition. Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- src/storage/storage_backend.c | 177 ++++++++++++++++++++++++++++++++---------- 1 file changed, 138 insertions(+), 39 deletions(-) diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c index 108f2b9..065f2ef 100644 --- a/src/storage/storage_backend.c +++ b/src/storage/storage_backend.c @@ -2639,37 +2639,117 @@ virStorageBackendFindGlusterPoolSources(const char *host ATTRIBUTE_UNUSED, #if WITH_BLKID + +typedef enum { + VIR_STORAGE_BLKID_PROBE_ERROR = -1, + VIR_STORAGE_BLKID_PROBE_UNDEFINED, /* Nothing found */ + VIR_STORAGE_BLKID_PROBE_UNKNOWN, /* Don't know libvirt fs/part type */ + VIR_STORAGE_BLKID_PROBE_MATCH, /* Matches the on disk format */ + VIR_STORAGE_BLKID_PROBE_DIFFERENT, /* Format doesn't match on disk format */ +} virStorageBackendBLKIDProbeResult; + +/* + * Utility function to probe for a file system on the device using the + * blkid "superblock" (e.g. default) APIs. + * + * NB: In general this helper will handle the virStoragePoolFormatFileSystem + * format types; however, if called from the Disk path, the initial fstype + * check will fail forcing the usage of the ProbePart helper. + * + * Returns virStorageBackendBLKIDProbeResult enum + */ +static virStorageBackendBLKIDProbeResult +virStorageBackendBLKIDProbeFS(blkid_probe probe, + const char *device, + const char *format) +{ + const char *fstype = NULL; + + /* Make sure we're doing a superblock probe from the start */ + blkid_probe_enable_superblocks(probe, true); + blkid_probe_reset_superblocks_filter(probe); + + if (blkid_do_probe(probe) != 0) { + VIR_INFO("No filesystem found on device '%s'", device); + return VIR_STORAGE_BLKID_PROBE_UNDEFINED; + } + + if (blkid_probe_lookup_value(probe, "TYPE", &fstype, NULL) == 0) { + if (STREQ(fstype, format)) + return VIR_STORAGE_BLKID_PROBE_MATCH; + + return VIR_STORAGE_BLKID_PROBE_DIFFERENT; + } + + if (blkid_known_fstype(format) == 0) + return VIR_STORAGE_BLKID_PROBE_UNKNOWN; + + return VIR_STORAGE_BLKID_PROBE_ERROR; +} + + +/* + * Utility function to probe for a partition on the device using the + * blkid "partitions" APIs. + * + * NB: In general, this API will be validating the virStoragePoolFormatDisk + * format types. + * + * Returns virStorageBackendBLKIDProbeResult enum + */ +static virStorageBackendBLKIDProbeResult +virStorageBackendBLKIDProbePart(blkid_probe probe, + const char *device, + const char *format) +{ + const char *pttype = NULL; + + /* Make sure we're doing a partitions probe from the start */ + blkid_probe_enable_partitions(probe, true); + blkid_probe_reset_partitions_filter(probe); + + if (blkid_do_probe(probe) != 0) { + VIR_INFO("No partition found on device '%s'", device); + return VIR_STORAGE_BLKID_PROBE_UNDEFINED; + } + + if (blkid_probe_lookup_value(probe, "PTTYPE", &pttype, NULL) == 0) { + if (STREQ(pttype, format)) + return VIR_STORAGE_BLKID_PROBE_MATCH; + + return VIR_STORAGE_BLKID_PROBE_DIFFERENT; + } + + if (blkid_known_pttype(format) == 0) + return VIR_STORAGE_BLKID_PROBE_UNKNOWN; + + return VIR_STORAGE_BLKID_PROBE_ERROR; +} + + /* * @device: Path to device * @format: Desired format * * Use the blkid_ APIs in order to get details regarding whether a file - * system exists on the disk already. + * system or partition exists on the disk already. * * Returns: * -1: An error was encountered, with error message set * 0: No file system found */ static int -virStorageBackendBLKIDProbeFS(const char *device, - const char *format) +virStorageBackendBLKIDProbe(const char *device, + const char *format) { int ret = -1; + int rc; blkid_probe probe = NULL; - const char *fstype = NULL; - VIR_DEBUG("Probing for existing filesystem of type %s on device %s", + VIR_DEBUG("Probe for existing filesystem/partition format %s on device %s", format, device); - if (blkid_known_fstype(format) == 0) { - virReportError(VIR_ERR_STORAGE_PROBE_FAILED, - _("Not capable of probing for filesystem of " - "type %s, requires --overwrite"), - format); - return -1; - } - if (!(probe = blkid_new_probe_from_filename(device))) { virReportError(VIR_ERR_STORAGE_PROBE_FAILED, _("Failed to create filesystem probe for device %s"), @@ -2677,34 +2757,53 @@ virStorageBackendBLKIDProbeFS(const char *device, return -1; } - if (blkid_do_probe(probe) != 0) { - VIR_INFO("No filesystem of type '%s' found on device '%s'", - format, device); - } else if (blkid_probe_lookup_value(probe, "TYPE", &fstype, NULL) == 0) { - if (STREQ(fstype, format)) { - virReportError(VIR_ERR_STORAGE_POOL_BUILT, - _("Device '%s' already contains a filesystem " - "of type '%s'"), - device, fstype); - } else { - virReportError(VIR_ERR_STORAGE_POOL_BUILT, - _("Existing filesystem of type '%s' found on " - "device '%s', requires --overwrite"), - fstype, device); - } - goto cleanup; + /* Look for something on FS, if it either doesn't recognize the + * format type as a valid FS format type or it doesn't find a valid + * format type on the device, then perform the same check using + * partition probing. */ + rc = virStorageBackendBLKIDProbeFS(probe, device, format); + if (rc == VIR_STORAGE_BLKID_PROBE_UNDEFINED || + rc == VIR_STORAGE_BLKID_PROBE_UNKNOWN) + rc = virStorageBackendBLKIDProbePart(probe, device, format); + + switch (rc) { + case VIR_STORAGE_BLKID_PROBE_UNDEFINED: + ret = 0; + break; + + case VIR_STORAGE_BLKID_PROBE_ERROR: + virReportError(VIR_ERR_STORAGE_PROBE_FAILED, + _("Failed to probe for format type '%s'"), format); + break; + + case VIR_STORAGE_BLKID_PROBE_UNKNOWN: + virReportError(VIR_ERR_STORAGE_PROBE_FAILED, + _("Not capable of probing for format type '%s', " + "requires build --overwrite"), + format); + break; + + case VIR_STORAGE_BLKID_PROBE_MATCH: + virReportError(VIR_ERR_STORAGE_POOL_BUILT, + _("Device '%s' already formatted using '%s'"), + device, format); + break; + + case VIR_STORAGE_BLKID_PROBE_DIFFERENT: + virReportError(VIR_ERR_STORAGE_POOL_BUILT, + _("Device '%s' formatted cannot overwrite using '%s', " + "requires build --overwrite"), + device, format); + break; } - if (blkid_do_probe(probe) != 1) { + if (ret == 0 && blkid_do_probe(probe) != 1) { virReportError(VIR_ERR_STORAGE_PROBE_FAILED, "%s", - _("Found additional probes to run, " - "filesystem probing may be incorrect")); - goto cleanup; + _("Found additional probes to run, probing may " + "be incorrect")); + ret = -1; } - ret = 0; - - cleanup: blkid_free_probe(probe); return ret; @@ -2713,8 +2812,8 @@ virStorageBackendBLKIDProbeFS(const char *device, #else /* #if WITH_BLKID */ static int -virStorageBackendBLKIDProbeFS(const char *device ATTRIBUTE_UNUSED, - const char *format ATTRIBUTE_UNUSED) +virStorageBackendBLKIDProbe(const char *device ATTRIBUTE_UNUSED, + const char *format ATTRIBUTE_UNUSED) { virReportError(VIR_ERR_OPERATION_INVALID, "%s", _("probing for filesystems is unsupported " @@ -2739,7 +2838,7 @@ bool virStorageBackendDeviceProbeEmpty(const char *devpath, const char *format) { - if (virStorageBackendBLKIDProbeFS(devpath, format) == 0) + if (virStorageBackendBLKIDProbe(devpath, format) == 0) true; return false; -- 2.7.4