Attachment 10040 Details for Bug 10663 – proposed patch for 4.0 and 4.1

[patch] proposed patch for 4.0 and 4.1

msg_channel-Fix-a-100-CPU-loop.patch (text/plain), 2.30 KB, created by Björn Baumbach on 2014-06-18 13:50:04 UTC

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Creator: Björn Baumbach

Created: 2014-06-18 13:50:04 UTC

Size: 2.30 KB

patch

obsolete

>From 6cd61f0d1e1e1a343d9eb017714d6d093cedacfb Mon Sep 17 00:00:00 2001
>From: Volker Lendecke <vl@samba.org>
>Date: Tue, 10 Jun 2014 14:21:07 +0000
>Subject: [PATCH] msg_channel: Fix a 100% CPU loop
>
>In a ctdb setup, msg_read_got_ctdb did not set channel->pending_req to
>NULL. In smbXsrv_session_close_loop in any error condition this leads to
>a 100% loop. smbXsrv_session_close_loop continously retries, but because
>close_channel->pending_req is != NULL, msg_read_send will always return
>EBUSY, making smbXsrv_session_close_loop retry infinitely.
>
>This patch makes sure that msg_read_got_ctdb correctly NULLs out pending_req.
>
>msg_channel.c does not exist in master anymore, so this patch is 4.1 only.
>
>Signed-off-by: Volker Lendecke <vl@samba.org>
>---
> source3/lib/msg_channel.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
>diff --git a/source3/lib/msg_channel.c b/source3/lib/msg_channel.c
>index 8e23fd4..55d102a 100644
>--- a/source3/lib/msg_channel.c
>+++ b/source3/lib/msg_channel.c
>@@ -213,6 +213,7 @@ fail:
> }
> 
> static void msg_read_got_ctdb(struct tevent_req *subreq);
>+static int msg_read_state_destructor(struct msg_read_state *s);
> 
> struct tevent_req *msg_read_send(TALLOC_CTX *mem_ctx,
> 				 struct tevent_context *ev,
>@@ -248,6 +249,8 @@ struct tevent_req *msg_read_send(TALLOC_CTX *mem_ctx,
> 	}
> 
> 	channel->pending_req = req;
>+	talloc_set_destructor(state, msg_read_state_destructor);
>+
> 	channel->ev = ev;
> 
> 	msg_tdb_event = messaging_tdb_event(state, channel->msg, ev);
>@@ -268,6 +271,12 @@ struct tevent_req *msg_read_send(TALLOC_CTX *mem_ctx,
> 	return req;
> }
> 
>+static int msg_read_state_destructor(struct msg_read_state *s)
>+{
>+	s->channel->pending_req = NULL;
>+	return 0;
>+}
>+
> static void msg_read_got_ctdb(struct tevent_req *subreq)
> {
> 	struct tevent_req *req = tevent_req_callback_data(
>@@ -278,6 +287,8 @@ static void msg_read_got_ctdb(struct tevent_req *subreq)
> 	enum ndr_err_code ndr_err;
> 	int ret;
> 
>+	state->channel->pending_req = NULL;
>+
> 	ret = ctdb_msg_read_recv(subreq, talloc_tos(),
> 				 &blob.data, &blob.length);
> 	TALLOC_FREE(subreq);
>@@ -316,6 +327,7 @@ static void msg_read_got_ctdb(struct tevent_req *subreq)
> 		return;
> 	}
> 	tevent_req_set_callback(subreq, msg_read_got_ctdb, req);
>+	state->channel->pending_req = req;
> }
> 
> int msg_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
>-- 
>1.8.1.2
>

Flags:

metze: review+
vl: review+

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Attachments on bug 10663: 10040