[Libguestfs] [PATCH v2 5/5] launch: direct: Disable qemu locking when opening drives readonly (RHBZ#1417306).

--- lib/launch-direct.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/lib/launch-direct.c b/lib/launch-direct.c index 9f85013f9..00cb25077 100644 --- a/lib/launch-direct.c +++ b/lib/launch-direct.c @@ -66,6 +66,7 @@ struct backend_direct_data { pid_t recoverypid; /* Recovery process PID. */ struct version qemu_version; /* qemu version (0 if unable to parse). */ + int qemu_mandatory_locking; /* qemu >= 2.10 does mandatory locking */ struct qemu_data *qemu_data; /* qemu -help output etc. */ char guestfsd_sock[UNIX_PATH_MAX]; /* Path to daemon socket. */ @@ -255,11 +256,13 @@ add_drive_standard_params (guestfs_h *g, struct backend_direct_data *data, } else { /* Writable qcow2 overlay on top of read-only drive. */ - append_list_format ("file=%s", drv->overlay); + append_list_format ("file.file.filename=%s", drv->overlay); + append_list ("file.driver=qcow2"); append_list ("cache=unsafe"); - append_list ("format=qcow2"); if (drv->disk_label) append_list_format ("serial=%s", drv->disk_label); + if (data->qemu_mandatory_locking) + append_list ("file.backing.file.locking=off"); } append_list_format ("id=hd%zu", i); @@ -408,6 +411,10 @@ launch_direct (guestfs_h *g, void *datav, const char *arg) data->qemu_version = guestfs_int_qemu_version (g, data->qemu_data); debug (g, "qemu version: %d.%d", data->qemu_version.v_major, data->qemu_version.v_minor); + data->qemu_mandatory_locking = + guestfs_int_qemu_mandatory_locking (g, data->qemu_data); + debug (g, "qemu mandatory locking: %s", + data->qemu_mandatory_locking ? "yes" : "no"); } /* Using virtio-serial, we need to create a local Unix domain socket -- 2.13.2