Merge tag 'ceph-for-4.11-rc4' of git://github.com/ceph/ceph-client

Pull ceph fix from Ilya Dryomov:
 "A fix for a writeback deadlock caused by a GFP_KERNEL allocation on
  the reclaim path, tagged for stable"

* tag 'ceph-for-4.11-rc4' of git://github.com/ceph/ceph-client:
  libceph: force GFP_NOIO for socket allocations

1 files changed, 6 insertions, 0 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 38dcf1eb427d..f76bb3332613 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -7,6 +7,7 @@
 #include <linux/kthread.h>
 #include <linux/net.h>
 #include <linux/nsproxy.h>
+#include <linux/sched/mm.h>
 #include <linux/slab.h>
 #include <linux/socket.h>
 #include <linux/string.h>
@@ -469,11 +470,16 @@ static int ceph_tcp_connect(struct ceph_connection *con)
 {
         struct sockaddr_storage *paddr = &con->peer_addr.in_addr;
         struct socket *sock;
+        unsigned int noio_flag;
         int ret;
 
         BUG_ON(con->sock);
+
+        /* sock_create_kern() allocates with GFP_KERNEL */
+        noio_flag = memalloc_noio_save();
         ret = sock_create_kern(read_pnet(&con->msgr->net), paddr->ss_family,
                                SOCK_STREAM, IPPROTO_TCP, &sock);
+        memalloc_noio_restore(noio_flag);
         if (ret)
                 return ret;
         sock->sk->sk_allocation = GFP_NOFS;