Re: [PATCH 5/5] libxl: clean xenstore console directories recursively on destroy

Ian Campbell
Tue, 17 Apr 2012 14:37:13 -0000

On Tue, 2012-04-17 at 15:32 +0100, Roger Pau Monne
wrote:
> El 17/04/2012, a las 15:18, Roger Pau Monne escribió:
> > On Tue, 2012-04-17 at 15:18 +0100, Roger Pau Monne wrote:
> >> El 16/04/2012, a las 17:50, Ian Campbell escribió:
> >>> On Mon, 2012-04-16 at 16:06 +0100, Roger Pau Monne wrote:
> >>>> Clean xenstore, to prevent leaving empty directories in
the tree, like:
> >>>>
> >>>> /local/domain/0/backend/console = ""   (n0)
> >>>> /local/domain/0/backend/console/3 = ""   (n0)
> >>>>
> >>>> That was left after a guest was destroyed.
> >>>>
> >>>> Signed-off-by: Roger Pau Monne
<roger.pau@citrix.com>
> >>>> ---
> >>>> tools/libxl/libxl_device.c |    5 ++---
> >>>> 1 files changed, 2 insertions(+), 3 deletions(-)
> >>>>
> >>>> diff --git a/tools/libxl/libxl_device.c
b/tools/libxl/libxl_device.c
> >>>> index d773d71..4161d1bd 100644
> >>>> --- a/tools/libxl/libxl_device.c
> >>>> +++ b/tools/libxl/libxl_device.c
> >>>> @@ -609,12 +609,11 @@ out_ok:
> >>>>
> >>>> int libxl__device_destroy(libxl__gc *gc, libxl__device
*dev)
> >>>> {
> >>>> -    libxl_ctx *ctx = libxl__gc_owner(gc);
> >>>>    char *be_path = libxl__device_backend_path(gc, dev);
> >>>>    char *fe_path = libxl__device_frontend_path(gc, dev);
> >>>>
> >>>> -    xs_rm(ctx->xsh, XBT_NULL, be_path);
> >>>> -    xs_rm(ctx->xsh, XBT_NULL, fe_path);
> >>>> +    libxl__xs_path_cleanup(gc, fe_path);
> >>>> +    libxl__xs_path_cleanup(gc, be_path);
> >>>
> >>> is xs_rm not recursive? At least from the CLI it seems to be
> >>
> >> Ok, I got messed up here, what my function did was purge a
directory
> >> tree from top to bottom, so using your example, doing a:
> >>
> >> libxl__xs_path_cleanup(gc, "/foo/bar/baz");
> >>
> >> Would have erased /foo/bar/baz, /foo/bar and /foo, because they
where
> >> all empty (had no more files or subfolders inside) after deleting
> >> "baz".
> >
> > IFF they are empty? So the presence of /foo/bob would have made
> > only /foo/bar/baz and /foo/bar but not /foo get deleted?
>
>
> Yes, if there's a /foo/bob that would prevent the deletion of /foo.
> >
> > IOW it behaves like "xenstore-rm -t" (t for tidy)?
>
> From what I saw, yes (although I didn't even know of "xenstore-rm
-t").

Me neither till I looked at xenstore_client.c to see how my experiments
related to xs_rm...

>
> >
> >>
> >> So I guess this is really needed.
> >>
> >>>
> >>> quartz:~# xenstore-write /foo/bar/baz 123
> >>> quartz:~# xenstore-ls -f | grep foo
> >>> /foo = ""
> >>> /foo/bar = ""
> >>> /foo/bar/baz = "123"
> >>> quartz:~# xenstore-rm  /foo
> >>> quartz:~# xenstore-ls -f | grep foo
> >>> quartz:~#
> >>>
> >>> looking at xenstore_client.c it seems to only call xs_rm() and
not do
> >>> any traversal itself?
> >>>
> >>>>
> >>>>    libxl__device_destroy_tapdisk(gc, be_path);
> >>>>
> >>>
> >>>
> >>
> >>
> >
> >
>
>
>
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