Change in vdsm[ovirt-3.5]: vdsm: Fix memory leak in netlink.py

John Taylor has uploaded a new change for review.

Change subject: vdsm: Fix memory leak in netlink.py
......................................................................

vdsm: Fix memory leak in netlink.py

The documentation for libnl says that calls to rtnl_link_get_by_name
increment the reference counter and should be released by a call to
rtnl_link_put().  That's not done in the get_link(name) function where
it is used and causes a memory leak.

Add a C function prototype for the libnl rtnl_link_put function,
construct the link_info, and call rtnl_link_put before returning from
get_link(name).

Change-Id: I6e4dc72bd77e46ba4f95dd8a622f5c3288115315
Signed-off-by: John Taylor 
---
M lib/vdsm/netlink.py
1 file changed, 5 insertions(+), 2 deletions(-)

git pull ssh://gerrit.ovirt.org:29418/vdsm refs/changes/72/39372/1

diff --git a/lib/vdsm/netlink.py b/lib/vdsm/netlink.py
index afae5ce..d822944 100644
--- a/lib/vdsm/netlink.py
+++ b/lib/vdsm/netlink.py
@@ -64,8 +64,9 @@
             if not link:
                 raise IOError(errno.ENODEV, '%s is not present in the system' %
                               name)
-            return _link_info(cache, link)
-
+            link_info = _link_info(cache, link)
+            _rtnl_link_put(link)
+            return link_info

class NLSocketPool(object):
     """Pool of netlink sockets."""
@@ -332,5 +333,7 @@
 _nl_af2str = _int_char_proto(('nl_af2str', LIBNL))
 _rtnl_scope2str = _int_char_proto(('rtnl_scope2str', LIBNL_ROUTE))

+_rtnl_link_put  = _none_proto(('rtnl_link_put', LIBNL_ROUTE))
+
 _nl_link_cache = partial(_cache_manager, _rtnl_link_alloc_cache)
 _nl_addr_cache = partial(_cache_manager, _rtnl_addr_alloc_cache)

[e-mail] has posted comments on this change.

Change subject: vdsm: Fix memory leak in netlink.py
......................................................................

Patch Set 1: Verified-1

* Update tracker::IGNORE, no Bug-Url found

* Check Bug-Url::ERROR, At least one bug-url is required for the stable branch
* warn_if_not_merged_to_previous_branch: OK

[Dan Kenigsberg]

Dan Kenigsberg has posted comments on this change.

Change subject: vdsm: Fix memory leak in netlink.py
......................................................................

Patch Set 1: Code-Review-1

(1 comment)

Thanks again for the research and suggested fix. This patch should be first resolved on the master branch.

https://gerrit.ovirt.org/#/c/39372/1/lib/vdsm/netlink.py
File lib/vdsm/netlink.py:

Line 63: link_get_by_name
based only on cursory review of the libnl docs, it seems that this function too requires refcount maintenance.

John Taylor has posted comments on this change.

Change subject: vdsm: Fix memory leak in netlink.py
......................................................................

Patch Set 1:

(1 comment)

https://gerrit.ovirt.org/#/c/39372/1/lib/vdsm/netlink.py
File lib/vdsm/netlink.py:

Line 63: link_get_by_name
> based only on cursory review of the libnl docs, it seems that this function

the _rtnl_link_put on line 68 is the call that will decrement the refcount, allowing the later call to         _nl_cache_free(cache), done in the _cache_manager @contextmanager finally block, to be able to free the links in the cache. It might make more sense to do it like in master https://gerrit.ovirt.org/#/c/39416/  where it is immediately following the call to get the link.

[Dan Kenigsberg]

Dan Kenigsberg has abandoned this change.

Change subject: vdsm: Fix memory leak in netlink.py
......................................................................

Abandoned

taken https://gerrit.ovirt.org/40134 instead

[e-mail] has posted comments on this change.

Change subject: vdsm: Fix memory leak in netlink.py
......................................................................

Patch Set 1:

* Update tracker::IGNORE, no Bug-Url found