[libvirt] Re: [PATCH 2/6] Split virStorageGetMetadataFromFD() from virStorageBackendProbeTarget()

Prepare the code probing a file's format and associated metadata for moving into libvirt_util. * src/storage/storage_backend_fs.c: re-factor the format and metadata probing code in preparation for moving it --- src/storage/storage_backend_fs.c | 148 +++++++++++++++++++++++--------------- 1 files changed, 91 insertions(+), 57 deletions(-) diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c index e7a3ca9..87c30cd 100644 --- a/src/storage/storage_backend_fs.c +++ b/src/storage/storage_backend_fs.c @@ -283,49 +283,37 @@ static char *absolutePathFromBaseFile(const char *base_file, const char *path) * Probe the header of a file to determine what type of disk image * it is, and info about its capacity if available. */ -static int virStorageBackendProbeTarget(virConnectPtr conn, - virStorageVolTargetPtr target, - char **backingStore, - unsigned long long *allocation, - unsigned long long *capacity, - virStorageEncryptionPtr *encryption) { - int fd; +static int +virStorageGetMetadataFromFD(virConnectPtr conn, + const char *path, + int fd, + int *format, + bool *encrypted, + char **backingStore, + unsigned long long *capacity) +{ unsigned char head[20*512]; /* vmdk4GetBackingStore needs this much. */ - int len, i, ret; + int len, i; + if (format) /* If all else fails, call it a raw file */ + *format = VIR_STORAGE_FILE_RAW; + if (encrypted) + *encrypted = false; if (backingStore) *backingStore = NULL; - if (encryption) - *encryption = NULL; - - if ((fd = open(target->path, O_RDONLY)) < 0) { - virReportSystemError(conn, errno, - _("cannot open volume '%s'"), - target->path); - return -1; - } - - if ((ret = virStorageBackendUpdateVolTargetInfoFD(conn, target, fd, - allocation, - capacity)) < 0) { - close(fd); - return ret; /* Take care to propagate ret, it is not always -1 */ - } + /* Do not overwrite capacity + * if (capacity) + * *capacity = 0; + */ if ((len = read(fd, head, sizeof(head))) < 0) { - virReportSystemError(conn, errno, - _("cannot read header '%s'"), - target->path); - close(fd); + virReportSystemError(conn, errno, _("cannot read header '%s'"), path); return -1; } - close(fd); - /* First check file magic */ for (i = 0 ; i < ARRAY_CARDINALITY(fileTypeInfo) ; i++) { int mlen; - bool encrypted_qcow = false; if (fileTypeInfo[i].magic == NULL) continue; @@ -385,18 +373,19 @@ static int virStorageBackendProbeTarget(virConnectPtr conn, *capacity *= fileTypeInfo[i].sizeMultiplier; } - if (fileTypeInfo[i].qcowCryptOffset != -1) { + if (fileTypeInfo[i].qcowCryptOffset != -1 && encrypted) { int crypt_format; crypt_format = (head[fileTypeInfo[i].qcowCryptOffset] << 24) | (head[fileTypeInfo[i].qcowCryptOffset+1] << 16) | (head[fileTypeInfo[i].qcowCryptOffset+2] << 8) | head[fileTypeInfo[i].qcowCryptOffset+3]; - encrypted_qcow = crypt_format != 0; + *encrypted = crypt_format != 0; } /* Validation passed, we know the file format now */ - target->format = fileTypeInfo[i].type; + if (format) + *format = fileTypeInfo[i].type; if (fileTypeInfo[i].getBackingStore != NULL && backingStore) { char *base; @@ -411,8 +400,7 @@ static int virStorageBackendProbeTarget(virConnectPtr conn, return -1; } if (base != NULL) { - *backingStore - = absolutePathFromBaseFile(target->path, base); + *backingStore = absolutePathFromBaseFile(path, base); VIR_FREE(base); if (*backingStore == NULL) { virReportOOMError(conn); @@ -420,23 +408,6 @@ static int virStorageBackendProbeTarget(virConnectPtr conn, } } } - if (encryption != NULL && encrypted_qcow) { - virStorageEncryptionPtr enc; - - if (VIR_ALLOC(enc) < 0) { - virReportOOMError(conn); - if (backingStore) - VIR_FREE(*backingStore); - return -1; - } - enc->format = VIR_STORAGE_ENCRYPTION_FORMAT_QCOW; - *encryption = enc; - /* XXX ideally we'd fill in secret UUID here - * but we cannot guarentee 'conn' is non-NULL - * at this point in time :-( So we only fill - * in secrets when someone first queries a vol - */ - } return 0; } @@ -445,15 +416,78 @@ static int virStorageBackendProbeTarget(virConnectPtr conn, if (fileTypeInfo[i].extension == NULL) continue; - if (!virFileHasSuffix(target->path, fileTypeInfo[i].extension)) + if (!virFileHasSuffix(path, fileTypeInfo[i].extension)) continue; - target->format = fileTypeInfo[i].type; + if (format) + *format = fileTypeInfo[i].type; return 0; } - /* All fails, so call it a raw file */ - target->format = VIR_STORAGE_FILE_RAW; + return 0; +} + +static int +virStorageBackendProbeTarget(virConnectPtr conn, + virStorageVolTargetPtr target, + char **backingStore, + unsigned long long *allocation, + unsigned long long *capacity, + virStorageEncryptionPtr *encryption) +{ + int fd, ret; + bool encrypted; + + if (encryption) + *encryption = NULL; + + if ((fd = open(target->path, O_RDONLY)) < 0) { + virReportSystemError(conn, errno, + _("cannot open volume '%s'"), + target->path); + return -1; + } + + if ((ret = virStorageBackendUpdateVolTargetInfoFD(conn, target, fd, + allocation, + capacity)) < 0) { + close(fd); + return ret; /* Take care to propagate ret, it is not always -1 */ + } + + if (virStorageGetMetadataFromFD(conn, target->path, fd, + &target->format, &encrypted, + backingStore, capacity) < 0) { + close(fd); + return -1; + } + + close(fd); + + if (encryption != NULL && encrypted) { + if (VIR_ALLOC(*encryption) < 0) { + virReportOOMError(conn); + if (backingStore) + VIR_FREE(*backingStore); + return -1; + } + + switch (target->format) { + case VIR_STORAGE_FILE_QCOW: + case VIR_STORAGE_FILE_QCOW2: + (*encryption)->format = VIR_STORAGE_ENCRYPTION_FORMAT_QCOW; + break; + default: + break; + } + + /* XXX ideally we'd fill in secret UUID here + * but we cannot guarentee 'conn' is non-NULL + * at this point in time :-( So we only fill + * in secrets when someone first queries a vol + */ + } + return 0; }