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>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index e3be1d2..0f9ea60 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -276,22 +276,22 @@
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.