diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c index eb60fd5..47b5afc 100644 --- a/tools/libxl/libxl_device.c +++ b/tools/libxl/libxl_device.c @@ -143,7 +143,6 @@ retry_transaction: typedef struct { libxl__gc *gc; libxl_device_disk *disk; - struct stat stab; } disk_try_backend_args; static int disk_try_backend(disk_try_backend_args *a, @@ -153,6 +152,7 @@ static int disk_try_backend(disk_try_backend_args *a, /* returns 0 (ie, DISK_BACKEND_UNKNOWN) on failure, or * backend on success */ libxl_ctx *ctx = libxl__gc_owner(gc); + struct stat stab; switch (backend) { case LIBXL_DISK_BACKEND_PHY: @@ -167,13 +167,21 @@ static int disk_try_backend(disk_try_backend_args *a, return backend; } - if (libxl__try_phy_backend(a->stab.st_mode)) - return backend; + if (a->disk->backend_domid == LIBXL_TOOLSTACK_DOMID) { + if (stat(a->disk->pdev_path, &stab)) { + LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Disk vdev=%s " + "failed to stat: %s", + a->disk->vdev, a->disk->pdev_path); + return 0; + } - LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "Disk vdev=%s, backend phy" - " unsuitable as phys path not a block device", + if (libxl__try_phy_backend(stab.st_mode)) + return backend; + } + + LOG(DEBUG, "Disk vdev=%s, uses driver domain, assuming phy backend", a->disk->vdev); - return 0; + return backend; case LIBXL_DISK_BACKEND_TAP: if (a->disk->script) goto bad_script; @@ -228,30 +236,11 @@ int libxl__device_disk_set_backend(libxl__gc *gc, libxl_device_disk *disk) { disk->vdev, libxl_disk_backend_to_string(disk->backend)); - if (disk->format == LIBXL_DISK_FORMAT_EMPTY) { - if (!disk->is_cdrom) { - LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Disk vdev=%s is empty" - " but not cdrom", - disk->vdev); - return ERROR_INVAL; - } - memset(&a.stab, 0, sizeof(a.stab)); - } 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", - disk->vdev, disk->pdev_path); - return ERROR_INVAL; - } - if (!S_ISBLK(a.stab.st_mode) & - !S_ISREG(a.stab.st_mode)) { - LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Disk vdev=%s " - "phys path is not a block dev or file: %s", - disk->vdev, disk->pdev_path); - return ERROR_INVAL; - } + if (disk->format == LIBXL_DISK_FORMAT_EMPTY && !disk->is_cdrom) { + LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Disk vdev=%s is empty" + " but not cdrom", + disk->vdev); + return ERROR_INVAL; } if (disk->backend != LIBXL_DISK_BACKEND_UNKNOWN) {