Anthony, could you please take a look?
Thank you in advance,
Oleksandr
On 10.12.21 14:35, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
>
> vchan server creates XenStore entries to advertise its event channel and
> ring, but those are not removed after the server quits.
> Add additional cleanup step, so those are removed, so clients do not try
> to connect to a non-existing server.
>
> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
> ---
> tools/include/libxenvchan.h | 5 +++++
> tools/libs/vchan/init.c | 23 +++++++++++++++++++++++
> tools/libs/vchan/io.c | 4 ++++
> tools/libs/vchan/vchan.h | 31 +++++++++++++++++++++++++++++++
> 4 files changed, 63 insertions(+)
> create mode 100644 tools/libs/vchan/vchan.h
>
> diff --git a/tools/include/libxenvchan.h b/tools/include/libxenvchan.h
> index d6010b145df2..30cc73cf97e3 100644
> --- a/tools/include/libxenvchan.h
> +++ b/tools/include/libxenvchan.h
> @@ -86,6 +86,11 @@ struct libxenvchan {
> int blocking:1;
> /* communication rings */
> struct libxenvchan_ring read, write;
> + /**
> + * Base xenstore path for storing ring/event data used by the server
> + * during cleanup.
> + * */
> + char *xs_path;
> };
>
> /**
> diff --git a/tools/libs/vchan/init.c b/tools/libs/vchan/init.c
> index c8510e6ce98a..c6b8674ef541 100644
> --- a/tools/libs/vchan/init.c
> +++ b/tools/libs/vchan/init.c
> @@ -46,6 +46,8 @@
> #include <xen/sys/gntdev.h>
> #include <libxenvchan.h>
>
> +#include "vchan.h"
> +
> #ifndef PAGE_SHIFT
> #define PAGE_SHIFT 12
> #endif
> @@ -251,6 +253,10 @@ static int init_xs_srv(struct libxenvchan *ctrl, int
> domain, const char* xs_base
> char ref[16];
> char* domid_str = NULL;
> xs_transaction_t xs_trans = XBT_NULL;
> +
> + // store the base path so we can clean up on server closure
> + ctrl->xs_path = strdup(xs_base);
> +
> xs = xs_open(0);
> if (!xs)
> goto fail;
> @@ -298,6 +304,23 @@ retry_transaction:
> return ret;
> }
>
> +void close_xs_srv(struct libxenvchan *ctrl)
> +{
> + struct xs_handle *xs;
> +
> + if (!ctrl->xs_path)
> + return;
> +
> + xs = xs_open(0);
> + if (!xs)
> + goto fail;
> +
> + xs_rm(xs, XBT_NULL, ctrl->xs_path);
> +
> +fail:
> + free(ctrl->xs_path);
> +}
> +
> static int min_order(size_t siz)
> {
> int rv = PAGE_SHIFT;
> diff --git a/tools/libs/vchan/io.c b/tools/libs/vchan/io.c
> index da303fbc01ca..1f201ad554f2 100644
> --- a/tools/libs/vchan/io.c
> +++ b/tools/libs/vchan/io.c
> @@ -40,6 +40,8 @@
> #include <xenctrl.h>
> #include <libxenvchan.h>
>
> +#include "vchan.h"
> +
> #ifndef PAGE_SHIFT
> #define PAGE_SHIFT 12
> #endif
> @@ -384,5 +386,7 @@ void libxenvchan_close(struct libxenvchan *ctrl)
> if (ctrl->gnttab)
> xengnttab_close(ctrl->gnttab);
> }
> + if (ctrl->is_server)
> + close_xs_srv(ctrl);
> free(ctrl);
> }
> diff --git a/tools/libs/vchan/vchan.h b/tools/libs/vchan/vchan.h
> new file mode 100644
> index 000000000000..621016ef42e5
> --- /dev/null
> +++ b/tools/libs/vchan/vchan.h
> @@ -0,0 +1,31 @@
> +/**
> + * @file
> + * @section AUTHORS
> + *
> + * Copyright (C) 2021 EPAM Systems Inc.
> + *
> + * @section LICENSE
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; If not, see
> <http://www.gnu.org/licenses/>.
> + *
> + * @section DESCRIPTION
> + *
> + * This file contains common libxenvchan declarations.
> + */
> +#ifndef LIBVCHAN_H
> +#define LIBVCHAN_H
> +
> +void close_xs_srv(struct libxenvchan *ctrl);
> +
> +#endif /* LIBVCHAN_H */
