From: Luca Fancellu <luca.fancellu@arm.com>
To: Julien Grall <julien@xen.org>
Cc: xen-devel@lists.xenproject.org, raphning@amazon.co.uk,
doebel@amazon.de, Julien Grall <jgrall@amazon.com>,
Ian Jackson <iwj@xenproject.org>, Wei Liu <wl@xen.org>,
Juergen Gross <jgross@suse.com>
Subject: Re: [PATCH 04/10] tools/xenstored: Limit the number of requests a connection can delay
Date: Mon, 21 Jun 2021 10:02:01 +0100 [thread overview]
Message-ID: <77658E0F-C333-430C-A0E4-13F08E943A8B@arm.com> (raw)
In-Reply-To: <20210616144324.31652-5-julien@xen.org>
> On 16 Jun 2021, at 15:43, Julien Grall <julien@xen.org> wrote:
>
> From: Julien Grall <jgrall@amazon.com>
>
> Currently, only liveupdate request can be delayed. The request can only
> be performed by a privileged connection (e.g. dom0). So it is fine to
> have no limits.
>
> In a follow-up patch we will want to delay request for unprivileged
> connection as well. So it is best to apply a limit.
>
> For now and for simplicity, only a single request can be delayed
> for a given unprivileged connection.
>
> Take the opportunity to tweak the prototype and provide a way to
> bypass the quota check. This would be useful when the function
> is called from the restore code.
>
> Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
> ---
> tools/xenstore/xenstored_control.c | 2 +-
> tools/xenstore/xenstored_core.c | 11 ++++++++++-
> tools/xenstore/xenstored_core.h | 3 ++-
> 3 files changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/tools/xenstore/xenstored_control.c b/tools/xenstore/xenstored_control.c
> index 7acc2d134f9f..1c24d4869eab 100644
> --- a/tools/xenstore/xenstored_control.c
> +++ b/tools/xenstore/xenstored_control.c
> @@ -737,7 +737,7 @@ static const char *lu_start(const void *ctx, struct connection *conn,
> lu_status->timeout = to;
> lu_status->started_at = time(NULL);
>
> - errno = delay_request(conn, conn->in, do_lu_start, NULL);
> + errno = delay_request(conn, conn->in, do_lu_start, NULL, false);
>
> return NULL;
> }
> diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
> index 41b26d7094c8..51d210828922 100644
> --- a/tools/xenstore/xenstored_core.c
> +++ b/tools/xenstore/xenstored_core.c
> @@ -279,10 +279,19 @@ static void call_delayed(struct connection *conn, struct delayed_request *req)
> }
>
> int delay_request(struct connection *conn, struct buffered_data *in,
> - bool (*func)(struct delayed_request *), void *data)
> + bool (*func)(struct delayed_request *), void *data,
> + bool no_quota_check)
> {
> struct delayed_request *req;
>
> + /*
> + * Only allow one request can be delayed for an unprivileged
> + * connection.
> + */
> + if (!no_quota_check && domain_is_unprivileged(conn) &&
> + !list_empty(&conn->delayed))
> + return ENOSPC;
> +
> req = talloc(in, struct delayed_request);
> if (!req)
> return ENOMEM;
> diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
> index 89ce155e755b..34839b34f6e9 100644
> --- a/tools/xenstore/xenstored_core.h
> +++ b/tools/xenstore/xenstored_core.h
> @@ -213,7 +213,8 @@ char *get_parent(const void *ctx, const char *node);
>
> /* Delay a request. */
> int delay_request(struct connection *conn, struct buffered_data *in,
> - bool (*func)(struct delayed_request *), void *data);
> + bool (*func)(struct delayed_request *), void *data,
> + bool no_quota_check);
>
> /* Tracing infrastructure. */
> void trace_create(const void *data, const char *type);
> --
> 2.17.1
>
>
next prev parent reply other threads:[~2021-06-21 9:03 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-16 14:43 [PATCH 00/10] tools/xenstored: Bug fixes + Improve Live-Update Julien Grall
2021-06-16 14:43 ` [PATCH 01/10] MAINTAINERS: Add myself as reviewers for tools/xenstore Julien Grall
2021-06-16 15:15 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 02/10] tools/xenstored: Introduce lu_get_connection() and use it Julien Grall
2021-06-21 8:21 ` Luca Fancellu
2021-06-24 7:21 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 03/10] tools/xenstore: Don't assume conn->in points to the LU request Julien Grall
2021-06-21 8:55 ` Luca Fancellu
2021-06-24 8:06 ` Julien Grall
2021-06-24 7:32 ` Juergen Gross
2021-06-24 7:34 ` Juergen Gross
2021-06-24 7:56 ` Luca Fancellu
2021-06-24 8:05 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 04/10] tools/xenstored: Limit the number of requests a connection can delay Julien Grall
2021-06-21 9:02 ` Luca Fancellu [this message]
2021-06-24 7:35 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 05/10] tools/xenstored: xenstored_core.h should include fcntl.h Julien Grall
2021-06-21 9:03 ` Luca Fancellu
2021-06-24 7:36 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 06/10] tools/xenstored: Introduce a wrapper for conn->funcs->can_{read, write} Julien Grall
2021-06-21 9:10 ` Luca Fancellu
2021-06-24 7:39 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 07/10] tools/xenstored: delay_request: don't assume conn->in == in Julien Grall
2021-06-21 9:12 ` Luca Fancellu
2021-06-24 7:44 ` Juergen Gross
2021-06-24 7:58 ` Julien Grall
2021-06-16 14:43 ` [PATCH 08/10] tools/xenstored: Extend restore code to handle multiple input buffer Julien Grall
2021-06-21 9:21 ` Luca Fancellu
2021-06-24 8:30 ` Juergen Gross
2021-06-24 8:42 ` Julien Grall
2021-06-24 9:20 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 09/10] tools/xenstored: Dump delayed requests Julien Grall
2021-06-21 9:27 ` Luca Fancellu
2021-06-24 8:41 ` Juergen Gross
2021-06-24 10:28 ` Julien Grall
2021-06-24 10:45 ` Juergen Gross
2021-06-24 10:46 ` Julien Grall
2021-06-24 11:02 ` Juergen Gross
2021-06-24 11:17 ` Julien Grall
2021-06-16 14:43 ` [PATCH 10/10] tools/xenstored: Delay new transaction while Live-Update is pending Julien Grall
2021-06-21 9:30 ` Luca Fancellu
2021-06-24 9:23 ` Juergen Gross
2021-06-24 10:43 ` [PATCH 00/10] tools/xenstored: Bug fixes + Improve Live-Update Julien Grall
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