From a8a1f236a2964506a22d1779648d8e1c8668cb1a Mon Sep 17 00:00:00 2001 From: David Scott Date: Tue, 23 Apr 2013 10:59:26 +0100 Subject: [PATCH] libxl: Only call stat() when adding a disk if we expect a device to exist. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We consider calling stat() a helpful error check in the following circumstances only: 1. the disk backend type must be PHYsical 2. the disk backend domain must be the same as the running libxl code (ie LIBXL_TOOLSTACK_DOMID) 3. there must not be a hotplug script because this would imply that the device won't be created until after the hotplug script has run. With this fix, it is possible to use qemu's built-in block drivers such as ceph/rbd, with a xl config disk spec like this: disk=[ 'backendtype=qdisk,format=raw,vdev=hda,access=rw,target=rbd:rbd/ubuntu1204.img' ] Signed-off-by: David Scott Acked-by: Ian Campbell Acked-by: Roger Pau Monné --- tools/libxl/libxl_device.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c index eeea9d9a02..eb60fd543b 100644 --- a/tools/libxl/libxl_device.c +++ b/tools/libxl/libxl_device.c @@ -236,7 +236,9 @@ int libxl__device_disk_set_backend(libxl__gc *gc, libxl_device_disk *disk) { return ERROR_INVAL; } memset(&a.stab, 0, sizeof(a.stab)); - } else if (!disk->script) { + } else if (disk->backend == LIBXL_DISK_BACKEND_PHY && + disk->backend_domid == LIBXL_TOOLSTACK_DOMID && + !disk->script) { if (stat(disk->pdev_path, &a.stab)) { LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Disk vdev=%s " "failed to stat: %s", -- 2.30.2