Re: [libvirt] [PATCH] Allow relative path for qemu backing file

On 03/27/2011 07:30 PM, Jesse Cook wrote: > This patch enables the relative backing file path support provided by > qemu-img create. > > If a relative path is specified for the backing file, it is converted > to an absolute path using the storage pool path. The absolute path is > used to verify that the backing file exists. If the backing file exists, > the relative path is allowed and will be provided to qemu-img create. > > This patch takes the place of a previous patch: > http://www.redhat.com/archives/libvir-list/2011-March/msg00179.html > --- > src/storage/storage_backend.c | 18 +++++++++++++++++- > 1 files changed, 17 insertions(+), 1 deletions(-) Sorry for not reviewing this in time for 0.9.0.

> @@ -686,7 +689,20 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, > vol->backingStore.format); > return -1; > } > - if (access(vol->backingStore.path, R_OK) != 0) { > + > + /* Convert relative backing store paths to absolute paths for access > + * validation. > + */ > + if ('/' != *(vol->backingStore.path)) { > + virAsprintf(&absolutePath, "%s/%s", pool->def->target.path, > + vol->backingStore.path); > + > + } else { > + virAsprintf(&absolutePath, "%s", vol->backingStore.path); strdup is more efficient here, and avoiding malloc in the first place even more so. > + } > + accessRetCode = access(absolutePath, R_OK); This could segfault on OOM. > + VIR_FREE(absolutePath);

> + if (accessRetCode != 0) { > virReportSystemError(errno, > _("inaccessible backing store volume %s"), > vol->backingStore.path); ACK with nits fixed; so here's what I squashed in before pushing. I also updated AUTHORS to pass 'make syntax-check'; feel free to let me know off-list if you prefer any alternate spelling there (especially since you sent v1 and v2 under different email aliases). diff --git i/src/storage/storage_backend.c w/src/storage/storage_backend.c index 5f5565b..8af2878 100644 --- i/src/storage/storage_backend.c +++ w/src/storage/storage_backend.c @@ -693,7 +693,6 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, if (vol->backingStore.path) { int accessRetCode = -1; - char *absolutePath = NULL; /* XXX: Not strictly required: qemu-img has an option a different @@ -719,14 +718,14 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, /* Convert relative backing store paths to absolute paths for access * validation. */ - if ('/' != *(vol->backingStore.path)) { + if ('/' != *(vol->backingStore.path) && virAsprintf(&absolutePath, "%s/%s", pool->def->target.path, - vol->backingStore.path); - - } else { - virAsprintf(&absolutePath, "%s", vol->backingStore.path); + vol->backingStore.path) < 0) { + virReportOOMError(); + return -1; } - accessRetCode = access(absolutePath, R_OK); + accessRetCode = access(absolutePath ? absolutePath + : vol->backingStore.path, R_OK); VIR_FREE(absolutePath); if (accessRetCode != 0) { virReportSystemError(errno,