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>

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index a150b59897a0299f347c15f86015b8bcc6c9a6c3..67d2bb3bb53391b2febcc1ab60362408389d4a75 100644 (file)
--- 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);