ceph: unwind canceled flock state

If we request a lock and then abort (e.g., ^C), we need to send a matching
unlock request to the MDS to unwind our lock attempt to avoid indefinitely
blocking other clients.

Reported-by: Brian Chrisman <brchrisman@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 16 insertions, 10 deletions

diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
index 7f0f72c53f7e..80576d05d687 100644
--- a/fs/ceph/locks.c
+++ b/fs/ceph/locks.c
@@ -33,11 +33,10 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
                 length = fl->fl_end - fl->fl_start + 1;
 
         dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
-             "length: %llu, wait: %d, type`: %d", (int)lock_type,
+             "length: %llu, wait: %d, type: %d", (int)lock_type,
              (int)operation, (u64)fl->fl_pid, fl->fl_start,
              length, wait, fl->fl_type);
 
-
         req->r_args.filelock_change.rule = lock_type;
         req->r_args.filelock_change.type = cmd;
         req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid);
@@ -71,7 +70,7 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
         }
         ceph_mdsc_put_request(req);
         dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
-             "length: %llu, wait: %d, type`: %d, err code %d", (int)lock_type,
+             "length: %llu, wait: %d, type: %d, err code %d", (int)lock_type,
              (int)operation, (u64)fl->fl_pid, fl->fl_start,
              length, wait, fl->fl_type, err);
         return err;
@@ -110,16 +109,20 @@ int ceph_lock(struct file *file, int cmd, struct file_lock *fl)
                         dout("mds locked, locking locally");
                         err = posix_lock_file(file, fl, NULL);
                         if (err && (CEPH_MDS_OP_SETFILELOCK == op)) {
-                                /* undo! This should only happen if the kernel detects
-                                 * local deadlock. */
+                                /* undo! This should only happen if
+                                 * the kernel detects local
+                                 * deadlock. */
                                 ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
                                                   CEPH_LOCK_UNLOCK, 0, fl);
-                                dout("got %d on posix_lock_file, undid lock", err);
+                                dout("got %d on posix_lock_file, undid lock",
+                                     err);
                         }
                 }
 
-        } else {
-                dout("mds returned error code %d", err);
+        } else if (err == -ERESTARTSYS) {
+                dout("undoing lock\n");
+                ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
+                                  CEPH_LOCK_UNLOCK, 0, fl);
         }
         return err;
 }
@@ -156,8 +159,11 @@ int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
                                           file, CEPH_LOCK_UNLOCK, 0, fl);
                         dout("got %d on flock_lock_file_wait, undid lock", err);
                 }
-        } else {
-                dout("mds error code %d", err);
+        } else if (err == -ERESTARTSYS) {
+                dout("undoing lock\n");
+                ceph_lock_message(CEPH_LOCK_FLOCK,
+                                  CEPH_MDS_OP_SETFILELOCK,
+                                  file, CEPH_LOCK_UNLOCK, 0, fl);
         }
         return err;
 }