ceph: unwind canceled flock state
Sage Weil [Wed, 25 May 2011 21:56:12 +0000 (14:56 -0700)]
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>

fs/ceph/locks.c

index 7f0f72c..80576d0 100644 (file)
@@ -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;
 }