[libvirt] [PATCH 6/6] storage: fs: Only force directory permissions if required

[Cole Robinson]

Only set directory permissions at pool build time, if:

- User explicitly requested a mode via the XML
- The directory needs to be created
- We need to do the crazy NFS root-squash workaround

This allows qemu:///session to call build on an existing directory
like /tmp.
---
 src/storage/storage_backend_fs.c | 16 +++++++++++-----
 src/util/virfile.c               |  2 +-
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index 344ee4c..e11c240 100644
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -769,6 +769,8 @@ virStorageBackendFileSystemBuild(virConnectPtr conn ATTRIBUTE_UNUSED,
     int err, ret = -1;
     char *parent = NULL;
     char *p = NULL;
+    mode_t mode;
+    bool needs_create_as_uid;
 
     virCheckFlags(VIR_STORAGE_POOL_BUILD_OVERWRITE |
                   VIR_STORAGE_POOL_BUILD_NO_OVERWRITE, ret);
@@ -802,19 +804,23 @@ virStorageBackendFileSystemBuild(virConnectPtr conn ATTRIBUTE_UNUSED,
         }
     }
 
+    needs_create_as_uid = (pool->def->type == VIR_STORAGE_POOL_NETFS);
+    mode = pool->def->target.perms.mode;
+    if (mode == (mode_t) -1 &&
+        (needs_create_as_uid || !virFileExists(pool->def->target.path)))
+        mode = VIR_STORAGE_DEFAULT_POOL_PERM_MODE;
+
     /* Now create the final dir in the path with the uid/gid/mode
      * requested in the config. If the dir already exists, just set
      * the perms. */
     if ((err = virDirCreate(pool->def->target.path,
-                            (pool->def->target.perms.mode == (mode_t) -1 ?
-                             VIR_STORAGE_DEFAULT_POOL_PERM_MODE :
-                             pool->def->target.perms.mode),
+                            mode,
                             pool->def->target.perms.uid,
                             pool->def->target.perms.gid,
                             VIR_DIR_CREATE_FORCE_PERMS |
                             VIR_DIR_CREATE_ALLOW_EXIST |
-                            (pool->def->type == VIR_STORAGE_POOL_NETFS
-                            ? VIR_DIR_CREATE_AS_UID : 0))) < 0) {
+                            (needs_create_as_uid ? VIR_DIR_CREATE_AS_UID : 0)
+                            )) < 0) {
         goto error;
     }
 
diff --git a/src/util/virfile.c b/src/util/virfile.c
index 676e7b4..7e49f39 100644
--- a/src/util/virfile.c
+++ b/src/util/virfile.c
@@ -2311,7 +2311,7 @@ virDirCreateNoFork(const char *path,
                              path, (unsigned int) uid, (unsigned int) gid);
         goto error;
     }
-    if ((flags & VIR_DIR_CREATE_FORCE_PERMS)
+    if (((flags & VIR_DIR_CREATE_FORCE_PERMS) && mode != (mode_t) -1)
         && (chmod(path, mode) < 0)) {
         ret = -errno;
         virReportSystemError(errno,
-- 
2.3.6