[libvirt] Re: [PATCH 3/6] Introduce virStorageFileMetadata structure

Introduce a metadata structure and make virStorageGetMetadataFromFD() fill it in. * src/util/storage_file.h: add virStorageFileMetadata * src/backend/storage_backend_fs.c: virStorageGetMetadataFromFD() now fills in the virStorageFileMetadata structure --- src/storage/storage_backend_fs.c | 65 ++++++++++++++++++------------------- src/util/storage_file.h | 8 +++++ 2 files changed, 40 insertions(+), 33 deletions(-) diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c index 87c30cd..7db73bf 100644 --- a/src/storage/storage_backend_fs.c +++ b/src/storage/storage_backend_fs.c @@ -287,24 +287,13 @@ static int virStorageGetMetadataFromFD(virConnectPtr conn, const char *path, int fd, - int *format, - bool *encrypted, - char **backingStore, - unsigned long long *capacity) + virStorageFileMetadata *meta) { unsigned char head[20*512]; /* vmdk4GetBackingStore needs this much. */ 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; - /* Do not overwrite capacity - * if (capacity) - * *capacity = 0; - */ + /* If all else fails, call it a raw file */ + meta->format = VIR_STORAGE_FILE_RAW; if ((len = read(fd, head, sizeof(head))) < 0) { virReportSystemError(conn, errno, _("cannot read header '%s'"), path); @@ -345,9 +334,9 @@ virStorageGetMetadataFromFD(virConnectPtr conn, } /* Optionally extract capacity from file */ - if (fileTypeInfo[i].sizeOffset != -1 && capacity) { + if (fileTypeInfo[i].sizeOffset != -1) { if (fileTypeInfo[i].endian == LV_LITTLE_ENDIAN) { - *capacity = + meta->capacity = ((unsigned long long)head[fileTypeInfo[i].sizeOffset+7] << 56) | ((unsigned long long)head[fileTypeInfo[i].sizeOffset+6] << 48) | ((unsigned long long)head[fileTypeInfo[i].sizeOffset+5] << 40) | @@ -357,7 +346,7 @@ virStorageGetMetadataFromFD(virConnectPtr conn, ((unsigned long long)head[fileTypeInfo[i].sizeOffset+1] << 8) | ((unsigned long long)head[fileTypeInfo[i].sizeOffset]); } else { - *capacity = + meta->capacity = ((unsigned long long)head[fileTypeInfo[i].sizeOffset] << 56) | ((unsigned long long)head[fileTypeInfo[i].sizeOffset+1] << 48) | ((unsigned long long)head[fileTypeInfo[i].sizeOffset+2] << 40) | @@ -368,25 +357,24 @@ virStorageGetMetadataFromFD(virConnectPtr conn, ((unsigned long long)head[fileTypeInfo[i].sizeOffset+7]); } /* Avoid unlikely, but theoretically possible overflow */ - if (*capacity > (ULLONG_MAX / fileTypeInfo[i].sizeMultiplier)) + if (meta->capacity > (ULLONG_MAX / fileTypeInfo[i].sizeMultiplier)) continue; - *capacity *= fileTypeInfo[i].sizeMultiplier; + meta->capacity *= fileTypeInfo[i].sizeMultiplier; } - if (fileTypeInfo[i].qcowCryptOffset != -1 && encrypted) { + if (fileTypeInfo[i].qcowCryptOffset != -1) { 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 = crypt_format != 0; + meta->encrypted = crypt_format != 0; } /* Validation passed, we know the file format now */ - if (format) - *format = fileTypeInfo[i].type; - if (fileTypeInfo[i].getBackingStore != NULL && backingStore) { + meta->format = fileTypeInfo[i].type; + if (fileTypeInfo[i].getBackingStore != NULL) { char *base; switch (fileTypeInfo[i].getBackingStore(conn, &base, head, len)) { @@ -400,9 +388,9 @@ virStorageGetMetadataFromFD(virConnectPtr conn, return -1; } if (base != NULL) { - *backingStore = absolutePathFromBaseFile(path, base); + meta->backingStore = absolutePathFromBaseFile(path, base); VIR_FREE(base); - if (*backingStore == NULL) { + if (meta->backingStore == NULL) { virReportOOMError(conn); return -1; } @@ -419,8 +407,7 @@ virStorageGetMetadataFromFD(virConnectPtr conn, if (!virFileHasSuffix(path, fileTypeInfo[i].extension)) continue; - if (format) - *format = fileTypeInfo[i].type; + meta->format = fileTypeInfo[i].type; return 0; } @@ -436,7 +423,7 @@ virStorageBackendProbeTarget(virConnectPtr conn, virStorageEncryptionPtr *encryption) { int fd, ret; - bool encrypted; + virStorageFileMetadata meta; if (encryption) *encryption = NULL; @@ -455,16 +442,28 @@ virStorageBackendProbeTarget(virConnectPtr conn, return ret; /* Take care to propagate ret, it is not always -1 */ } - if (virStorageGetMetadataFromFD(conn, target->path, fd, - &target->format, &encrypted, - backingStore, capacity) < 0) { + memset(&meta, 0, sizeof(meta)); + + if (virStorageGetMetadataFromFD(conn, target->path, fd, &meta) < 0) { close(fd); return -1; } close(fd); - if (encryption != NULL && encrypted) { + target->format = meta.format; + + if (backingStore) { + *backingStore = meta.backingStore; + meta.backingStore = NULL; + } + + VIR_FREE(meta.backingStore); + + if (capacity && meta.capacity) + *capacity = meta.capacity; + + if (encryption != NULL && meta.encrypted) { if (VIR_ALLOC(*encryption) < 0) { virReportOOMError(conn); if (backingStore) diff --git a/src/util/storage_file.h b/src/util/storage_file.h index 7bccbe4..b458c0e 100644 --- a/src/util/storage_file.h +++ b/src/util/storage_file.h @@ -25,6 +25,7 @@ #define __VIR_STORAGE_FILE_H__ #include "util.h" +#include <stdbool.h> enum virStorageFileFormat { VIR_STORAGE_FILE_RAW = 0, @@ -43,4 +44,11 @@ enum virStorageFileFormat { VIR_ENUM_DECL(virStorageFileFormat); +typedef struct _virStorageFileMetadata { + int format; + char *backingStore; + unsigned long long capacity; + bool encrypted; +} virStorageFileMetadata; + #endif /* __VIR_STORAGE_FILE_H__ */