diff options
Diffstat (limited to '0090-tools-xenstore-don-t-buffer-multiple-identical-watch.patch')
| -rw-r--r-- | 0090-tools-xenstore-don-t-buffer-multiple-identical-watch.patch | 93 |
1 files changed, 0 insertions, 93 deletions
diff --git a/0090-tools-xenstore-don-t-buffer-multiple-identical-watch.patch b/0090-tools-xenstore-don-t-buffer-multiple-identical-watch.patch deleted file mode 100644 index 305d8ac..0000000 --- a/0090-tools-xenstore-don-t-buffer-multiple-identical-watch.patch +++ /dev/null @@ -1,93 +0,0 @@ -From 97c251f953c58aec7620499ac12924054b7cd758 Mon Sep 17 00:00:00 2001 -From: Juergen Gross <jgross@suse.com> -Date: Tue, 13 Sep 2022 07:35:08 +0200 -Subject: [PATCH 090/126] tools/xenstore: don't buffer multiple identical watch - events - -A guest not reading its Xenstore response buffer fast enough might -pile up lots of Xenstore watch events buffered. Reduce the generated -load by dropping new events which already have an identical copy -pending. - -The special events "@..." are excluded from that handling as there are -known use cases where the handler is relying on each event to be sent -individually. - -This is part of XSA-326. - -Signed-off-by: Juergen Gross <jgross@suse.com> -Reviewed-by: Julien Grall <jgrall@amazon.com> -(cherry picked from commit b5c0bdb96d33e18c324c13d8e33c08732d77eaa2) ---- - tools/xenstore/xenstored_core.c | 20 +++++++++++++++++++- - tools/xenstore/xenstored_core.h | 3 +++ - 2 files changed, 22 insertions(+), 1 deletion(-) - -diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c -index d871f217af9c..6ea06e20df91 100644 ---- a/tools/xenstore/xenstored_core.c -+++ b/tools/xenstore/xenstored_core.c -@@ -882,6 +882,7 @@ void send_reply(struct connection *conn, enum xsd_sockmsg_type type, - bdata->inhdr = true; - bdata->used = 0; - bdata->timeout_msec = 0; -+ bdata->watch_event = false; - - if (len <= DEFAULT_BUFFER_SIZE) - bdata->buffer = bdata->default_buffer; -@@ -914,7 +915,7 @@ void send_reply(struct connection *conn, enum xsd_sockmsg_type type, - void send_event(struct buffered_data *req, struct connection *conn, - const char *path, const char *token) - { -- struct buffered_data *bdata; -+ struct buffered_data *bdata, *bd; - unsigned int len; - - len = strlen(path) + 1 + strlen(token) + 1; -@@ -936,12 +937,29 @@ void send_event(struct buffered_data *req, struct connection *conn, - bdata->hdr.msg.type = XS_WATCH_EVENT; - bdata->hdr.msg.len = len; - -+ /* -+ * Check whether an identical event is pending already. -+ * Special events are excluded from that check. -+ */ -+ if (path[0] != '@') { -+ list_for_each_entry(bd, &conn->out_list, list) { -+ if (bd->watch_event && bd->hdr.msg.len == len && -+ !memcmp(bdata->buffer, bd->buffer, len)) { -+ trace("dropping duplicate watch %s %s for domain %u\n", -+ path, token, conn->id); -+ talloc_free(bdata); -+ return; -+ } -+ } -+ } -+ - if (timeout_watch_event_msec && domain_is_unprivileged(conn)) { - bdata->timeout_msec = get_now_msec() + timeout_watch_event_msec; - if (!conn->timeout_msec) - conn->timeout_msec = bdata->timeout_msec; - } - -+ bdata->watch_event = true; - bdata->pend.req = req; - if (req) - req->pend.ref.event_cnt++; -diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h -index fcb27399f116..afbd982c2654 100644 ---- a/tools/xenstore/xenstored_core.h -+++ b/tools/xenstore/xenstored_core.h -@@ -62,6 +62,9 @@ struct buffered_data - /* Are we still doing the header? */ - bool inhdr; - -+ /* Is this a watch event? */ -+ bool watch_event; -+ - /* How far are we? */ - unsigned int used; - --- -2.37.4 - |