Commit d920ff6f authored Jun 25, 2015 by Benoît Canet Committed by Ilya Dryomov Sep 08, 2015

libceph: Avoid holding the zero page on ceph_msgr_slab_init errors



ceph_msgr_slab_init may fail due to a temporary ENOMEM.

Delay a bit the initialization of zero_page in ceph_msgr_init and
reorder its cleanup in _ceph_msgr_exit so it's done in reverse
order of setup.

BUG_ON() will not suffer to be postponed in case it is triggered.

Signed-off-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

parent b79b2368

net/ceph/messenger.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -276,22 +276,22 @@ static void _ceph_msgr_exit(void)
		ceph_msgr_wq = NULL;
		}

		ceph_msgr_slab_exit();

		BUG_ON(zero_page == NULL);
		page_cache_release(zero_page);
		zero_page = NULL;

		ceph_msgr_slab_exit();
		}

		int ceph_msgr_init(void)
		{
		if (ceph_msgr_slab_init())
		return -ENOMEM;

		BUG_ON(zero_page != NULL);
		zero_page = ZERO_PAGE(0);
		page_cache_get(zero_page);

		if (ceph_msgr_slab_init())
		return -ENOMEM;

		/*
		* The number of active work items is limited by the number of
		* connections, so leave @max_active at default.