libceph: ceph-msgr workqueue needs a resque worker

commit f9865f06f7f18c6661c88d0511f05c48612319cc upstream.

Commit f363e45fd118 ("net/ceph: make ceph_msgr_wq non-reentrant")
effectively removed WQ_MEM_RECLAIM flag from ceph_msgr_wq.  This is
wrong - libceph is very much a memory reclaim path, so restore it.

Cc: stable@vger.kernel.org # needs backporting for < 3.12
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Tested-by: Micha Krause <micha@krausam.de>
Reviewed-by: Sage Weil <sage@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 94e21b9b1c87793964eafcaefc2942ccc46cb245..057017bd3b42662772161ca77ed6775c27631e7f 100644 (file)
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -290,7 +290,11 @@ int ceph_msgr_init(void)
        if (ceph_msgr_slab_init())
                return -ENOMEM;
 
-       ceph_msgr_wq = alloc_workqueue("ceph-msgr", 0, 0);
+       /*
+        * The number of active work items is limited by the number of
+        * connections, so leave @max_active at default.
+        */
+       ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_MEM_RECLAIM, 0);
        if (ceph_msgr_wq)
                return 0;