Re: [libvirt] [PATCH 3/3] Create storage volumes directly with desired uid/gid.

In order to avoid problems trying to chown files that were created by root on a root-squashing nfs server, fork a new process that setuid's to the desired uid before creating the file. (It's only done this way if the pool containing the new volume is of type 'netfs', otherwise the old method of creating the file followed by chown() is used.) This changes the semantics of the "create_func" slightly - previously it was assumed that this function just created the file, then the caller would chown it to the desired uid. Now, create_func does both operations. There are multiple functions that can take on the role of create_func: createFileDir - previously called mkdir(), now calls virDirCreate(). virStorageBackendCreateRaw - previously called open(), now calls virFileCreate(). virStorageBackendCreateQemuImg - use virRunWithHook() to setuid/gid. virStorageBackendCreateQcowCreate - same. virStorageBackendCreateBlockFrom - preserve old behavior. --- src/storage/storage_backend.c | 115 ++++++++++++++++++++++++++++++++------ src/storage/storage_backend.h | 4 + src/storage/storage_backend_fs.c | 48 ++++++++++------ 3 files changed, 132 insertions(+), 35 deletions(-)

@@ -840,7 +833,15 @@ _virStorageBackendFileSystemVolBuild(virConnectPtr conn, static int virStorageBackendFileSystemVolBuild(virConnectPtr conn, virStorageVolDefPtr vol) { - return _virStorageBackendFileSystemVolBuild(conn, vol, NULL); + return _virStorageBackendFileSystemVolBuild(conn, vol, NULL, 0); +} + +/* version for vols created in netfs-based pools */ +static int +virStorageBackendFileSystemNetVolBuild(virConnectPtr conn, + virStorageVolDefPtr vol) { + return _virStorageBackendFileSystemVolBuild(conn, vol, NULL, + VIR_STORAGE_BUILD_NETFS); } /* @@ -851,9 +852,20 @@ virStorageBackendFileSystemVolBuildFrom(virConnectPtr conn, virStorageVolDefPtr vol, virStorageVolDefPtr inputvol, unsigned int flags ATTRIBUTE_UNUSED) { - return _virStorageBackendFileSystemVolBuild(conn, vol, inputvol); + return _virStorageBackendFileSystemVolBuild(conn, vol, inputvol, 0); +} + +/* version for vols created in netfs-based pools */ +static int +virStorageBackendFileSystemNetVolBuildFrom(virConnectPtr conn, + virStorageVolDefPtr vol, + virStorageVolDefPtr inputvol, + unsigned int flags ATTRIBUTE_UNUSED) { + return _virStorageBackendFileSystemVolBuild(conn, vol, inputvol, + VIR_STORAGE_BUILD_NETFS); }