Re: [Xen-devel] [PATCH v3 2/5] libxl: add libxl__xs_path_cleanup

[Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>]

Roger Pau Monne writes ("[Xen-devel] [PATCH v3 2/5] libxl: add 
libxl__xs_path_cleanup"):
> diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
> index c7e057d..36d58cd 100644
> --- a/tools/libxl/libxl_device.c
> +++ b/tools/libxl/libxl_device.c
> @@ -356,7 +356,6 @@ int libxl__device_disk_dev_number(const char *virtpath, 
> int *pdisk,
>      return -1;
>  }
>  
> -

Unrelated whitespace change.

> +/*
> + * Perfrom recursive cleanup of xenstore path, from top to bottom
> + * just like xenstore-rm -t
> + */
> +_hidden int libxl__xs_path_cleanup(libxl__gc *gc, char *path);

I think, following my confusion, that this needs some better
documentation comment.

> diff --git a/tools/libxl/libxl_xshelp.c b/tools/libxl/libxl_xshelp.c
> index 3ea8d08..0b1b844 100644
> --- a/tools/libxl/libxl_xshelp.c
> +++ b/tools/libxl/libxl_xshelp.c
> @@ -135,6 +135,28 @@ char *libxl__xs_libxl_path(libxl__gc *gc, uint32_t domid)
>      return s;
>  }
>  
> +int libxl__xs_path_cleanup(libxl__gc *gc, char *path)
> +{
> +    libxl_ctx *ctx = libxl__gc_owner(gc);
> +    unsigned int nb = 0;
> +    char *last;
> +
> +    if (!path)
> +        return 0;
> +
> +    xs_rm(ctx->xsh, XBT_NULL, path);
> +
> +    for (last = strrchr(path, '/'); last != NULL; last = strrchr(path, '/')) 
> {

If the path is relative, this won't work correctly.

Also this whole thing needs to take place in a transaction, or it is
racy.  Probably a transaction supplied by the caller, in which case
you should assert it.

> +        *last = '\0';
> +        if (!libxl__xs_directory(gc, XBT_NULL, path, &nb))
> +            continue;

If this fails, it should be a fatal error; we should not just blunder
on.

Ian.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel