On Fri, 2012-03-30 at 16:12 +0200, Gergely Nagy wrote:
Jakub Jankowski <shasta@toxcorp.com> writes:
I'm pretty sure this particular memory leak was fixed in 3.3.2, but then got reintroduced in this commit: http://git.balabit.hu/?p=bazsi/syslog-ng-3.3.git;a=commitdiff;h=c7070e2a6f1c... which was done to fix tcp() destination related crash after 3.3.2 was released.
So, Bazsi, yes - it does reintroduce the leak :) (in reply to your comment in https://lists.balabit.hu/pipermail/syslog-ng/2011-November/017697.html )
I think I found the solution: the reason for the crash in afsocket, which Bazsi fixed with killing the log_queue_unref in lib/driver.h was that it was missing a log_queue_ref. We didn't unref more than we should, we reffed less!
While I don't entirely understand the call chain, comparing how affile and afsocket did their queue magic, I prepared a patch that does not crash afsocket on reload, and stops the leak aswell. It also looks sane-ish to me, so I'm reasonably sure it's fine.
The patch is attached, I tested it as much as I could: no crash, no leak, no empty files. If you could test it too, it would be most appreciated!
differences between files attachment (0001-afsocket-Properly-release-our-queue-at-deinit.patch) From f15f8d91a28680092ba2ab0bd3ed64220d0ceba8 Mon Sep 17 00:00:00 2001 From: Gergely Nagy <algernon@balabit.hu> Date: Fri, 30 Mar 2012 16:00:17 +0200 Subject: [PATCH] afsocket: Properly release our queue at deinit
At deinit time, release the destination driver's queue explicitly. This allows us to re-add the implicit queue unref to log_dest_driver_release_queue().
This fixes the memory leak seen with, for example, file destinations.
Signed-off-by: Gergely Nagy <algernon@balabit.hu> --- lib/driver.h | 1 + modules/afsocket/afsocket.c | 3 +++ 2 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/lib/driver.h b/lib/driver.h index 7f7acbd..c805da5 100644 --- a/lib/driver.h +++ b/lib/driver.h @@ -188,6 +188,7 @@ log_dest_driver_release_queue(LogDestDriver *self, LogQueue *q) if (q) { self->queues = g_list_remove(self->queues, q); + log_queue_unref(q);
self->release_queue(self, q, self->release_queue_data); } diff --git a/modules/afsocket/afsocket.c b/modules/afsocket/afsocket.c index ae9c5c2..4e9002f 100644 --- a/modules/afsocket/afsocket.c +++ b/modules/afsocket/afsocket.c @@ -1217,6 +1217,9 @@ afsocket_dd_deinit(LogPipe *s) if (self->writer) log_pipe_deinit(self->writer);
+ log_dest_driver_release_queue(&self->super, log_writer_get_queue(self->writer));
this shouldn't be needed, as this is called automatically by log_dest_driver_deinit_method(), later in this function.
+ log_writer_set_queue(self->writer, NULL); +
This shouldn't be needed here.
if (self->flags & AFSOCKET_KEEP_ALIVE) { cfg_persist_config_add(cfg, afsocket_dd_format_persist_name(self, FALSE), self->writer, (GDestroyNotify) log_pipe_unref, FALSE);
You said, the issue was that we didn't put enough refs on the queue, that was the reason for the original crash. Can you describe where? Thanks. -- Bazsi