drbd: Finished the "on-no-data-accessible suspend-io;" functionality

When no data is accessible (no connection to the peer, nor a local disk)
allow the user to select to freeze all IO operations instead of getting
IO errors.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index ca4a16cea2d8..3c1e88480d37 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1173,6 +1173,24 @@ int w_send_read_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
         return ok;
 }
 
+int w_restart_disk_io(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
+{
+        struct drbd_request *req = container_of(w, struct drbd_request, w);
+
+        if (bio_data_dir(req->master_bio) == WRITE)
+                drbd_al_begin_io(mdev, req->sector);
+        /* Calling drbd_al_begin_io() out of the worker might deadlocks
+           theoretically. Practically it can not deadlock, since this is
+           only used when unfreezing IOs. All the extents of the requests
+           that made it into the TL are already active */
+
+        drbd_req_make_private_bio(req, req->master_bio);
+        req->private_bio->bi_bdev = mdev->ldev->backing_bdev;
+        generic_make_request(req->private_bio);
+
+        return 1;
+}
+
 static int _drbd_may_sync_now(struct drbd_conf *mdev)
 {
         struct drbd_conf *odev = mdev;