drbd: fix spurious warning about bitmap being locked from detach

Introduced in drbd: always write bitmap on detach,
the bitmap bulk writeout on detach was indicating
it expected exclusive bitmap access.

Where I meant to say: expect no more modifications,
but testing/counting is still allowed.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index a150b59897a0..67d2bb3bb533 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -3412,8 +3412,12 @@ static int w_go_diskless(struct drbd_work *w, int unused)
          * end up here after a failed attach, before ldev was even assigned.
          */
         if (mdev->bitmap && mdev->ldev) {
+                /* An interrupted resync or similar is allowed to recounts bits
+                 * while we detach.
+                 * Any modifications would not be expected anymore, though.
+                 */
                 if (drbd_bitmap_io_from_worker(mdev, drbd_bm_write,
-                                        "detach", BM_LOCKED_MASK)) {
+                                        "detach", BM_LOCKED_TEST_ALLOWED)) {
                         if (test_bit(WAS_READ_ERROR, &mdev->flags)) {
                                 drbd_md_set_flag(mdev, MDF_FULL_SYNC);
                                 drbd_md_sync(mdev);