[PATCH 4.9 099/130] ceph: fix ceph_get_caps() interruption

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yan, Zheng <z...@redhat.com>

commit 6e09d0fb64402cec579f029ca4c7f39f5c48fc60 upstream.

Commit 5c341ee32881 ("ceph: fix scheduler warning due to nested
blocking") causes infinite loop when process is interrupted.  Fix it.

Signed-off-by: Yan, Zheng <z...@redhat.com>
Signed-off-by: Ilya Dryomov <idryo...@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/ceph/caps.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2511,8 +2511,13 @@ int ceph_get_caps(struct ceph_inode_info
                        add_wait_queue(&ci->i_cap_wq, &wait);
 
                        while (!try_get_cap_refs(ci, need, want, endoff,
-                                                true, &_got, &err))
+                                                true, &_got, &err)) {
+                               if (signal_pending(current)) {
+                                       ret = -ERESTARTSYS;
+                                       break;
+                               }
                                wait_woken(&wait, TASK_INTERRUPTIBLE, 
MAX_SCHEDULE_TIMEOUT);
+                       }
 
                        remove_wait_queue(&ci->i_cap_wq, &wait);