Re: [libvirt] [PATCHv3 10/19] storage: remember relative names in backing chain

In order to search for a backing file name as literally present in a chain, we need to remember if the chain had relative names. Also, searching for absolute names is easier if we only have to canonicalize once, rather than on every iteration. * src/util/storage_file.h (_virStorageFileMetadata): Add field. * src/util/storage_file.c (virStorageFileGetMetadataFromBuf): (virStorageFileFreeMetadata): Manage it (absolutePathFromBaseFile): Store absolute names in canonical form. --- src/util/storage_file.c | 28 ++++++++++++++++++++-------- src/util/storage_file.h | 3 ++- 2 files changed, 22 insertions(+), 9 deletions(-) diff --git a/src/util/storage_file.c b/src/util/storage_file.c index 76079bb..2ff444c 100644 --- a/src/util/storage_file.c +++ b/src/util/storage_file.c @@ -28,6 +28,7 @@ #include <sys/stat.h> #include <unistd.h> #include <fcntl.h> +#include <stdlib.h> #ifdef __linux__ # if HAVE_LINUX_MAGIC_H # include <linux/magic.h> @@ -530,18 +531,22 @@ static char * absolutePathFromBaseFile(const char *base_file, const char *path) { char *res; + char *tmp; size_t d_len = dir_len (base_file); /* If path is already absolute, or if dirname(base_file) is ".", just return a copy of path. */ if (*path == '/' || d_len == 0) - return strdup(path); + return canonicalize_file_name(path); /* Ensure that the following cast-to-int is valid. */ if (d_len > INT_MAX) return NULL; - ignore_value(virAsprintf(&res, "%.*s/%s", (int) d_len, base_file, path)); + if (virAsprintf(&tmp, "%.*s/%s", (int) d_len, base_file, path) < 0) + return NULL; + res = canonicalize_file_name(tmp); + VIR_FREE(tmp); return res; } @@ -697,17 +702,23 @@ virStorageFileGetMetadataFromBuf(int format, meta->backingStoreIsFile = false; if (backing != NULL) { + meta->backingStore = strdup(backing); + if (meta->backingStore == NULL) { + virReportOOMError(); + VIR_FREE(backing); + return -1; + } if (virBackingStoreIsFile(backing)) { meta->backingStoreIsFile = true; + meta->backingStoreRaw = meta->backingStore; meta->backingStore = absolutePathFromBaseFile(path, backing); - } else { - meta->backingStore = strdup(backing); + if (meta->backingStore == NULL) { + virReportOOMError(); + VIR_FREE(backing); + return -1; + } } VIR_FREE(backing); - if (meta->backingStore == NULL) { - virReportOOMError(); - return -1; - } meta->backingStoreFormat = backingFormat; } else { meta->backingStore = NULL; @@ -1014,6 +1025,7 @@ virStorageFileFreeMetadata(virStorageFileMetadata *meta) virStorageFileFreeMetadata(meta->backingMeta); VIR_FREE(meta->backingStore); + VIR_FREE(meta->backingStoreRaw); VIR_FREE(meta); } diff --git a/src/util/storage_file.h b/src/util/storage_file.h index 9a60451..685fcb8 100644 --- a/src/util/storage_file.h +++ b/src/util/storage_file.h @@ -53,7 +53,8 @@ VIR_ENUM_DECL(virStorageFileFormat); typedef struct _virStorageFileMetadata virStorageFileMetadata; typedef virStorageFileMetadata *virStorageFileMetadataPtr; struct _virStorageFileMetadata { - char *backingStore; + char *backingStore; /* Canonical name (absolute file, or protocol) */ + char *backingStoreRaw; /* If file, original name, possibly relative */ int backingStoreFormat; /* enum virStorageFileFormat */ bool backingStoreIsFile; virStorageFileMetadataPtr backingMeta;