libceph: ceph-msgr workqueue needs a resque worker

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>

1 files changed, 5 insertions, 1 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 9764c771cfb1..559c9f619c20 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -292,7 +292,11 @@ 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;