drbd: complete_conflicting_writes() should not care about connections

complete_conflicting_writes() should not cause -EIO.
It should not timeout either, or care for connection states.

Connection timeout is detected elsewhere, and it's cleanup path is
supposed to remove any pending requests or peer_requests from the
write_requests tree.

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

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 1249672..c76402c 100644 (file)
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -800,21 +800,33 @@ static bool remote_due_to_read_balancing(struct drbd_conf *mdev, sector_t sector
  * The write_requests tree contains all active write requests which we
  * currently know about.  Wait for any requests to complete which conflict with
  * the new one.
+ *
+ * Only way out: remove the conflicting intervals from the tree.
  */
-static int complete_conflicting_writes(struct drbd_conf *mdev,
-                                      sector_t sector, int size)
+static void complete_conflicting_writes(struct drbd_request *req)
 {
-       for(;;) {
-               struct drbd_interval *i;
-               int err;
+       DEFINE_WAIT(wait);
+       struct drbd_conf *mdev = req->w.mdev;
+       struct drbd_interval *i;
+       sector_t sector = req->i.sector;
+       int size = req->i.size;
 
+       i = drbd_find_overlap(&mdev->write_requests, sector, size);
+       if (!i)
+               return;
+
+       for (;;) {
+               prepare_to_wait(&mdev->misc_wait, &wait, TASK_UNINTERRUPTIBLE);
                i = drbd_find_overlap(&mdev->write_requests, sector, size);
                if (!i)
-                       return 0;
-               err = drbd_wait_misc(mdev, i);
-               if (err)
-                       return err;
+                       break;
+               /* Indicate to wake up device->misc_wait on progress.  */
+               i->waiting = true;
+               spin_unlock_irq(&mdev->tconn->req_lock);
+               schedule();
+               spin_lock_irq(&mdev->tconn->req_lock);
        }
+       finish_wait(&mdev->misc_wait, &wait);
 }
 
 int __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)
@@ -826,7 +838,7 @@ int __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long s
        struct drbd_request *req;
        struct net_conf *nc;
        int local, remote, send_oos = 0;
-       int err;
+       int err = 0;
        int ret = 0;
        union drbd_dev_state s;
 
@@ -925,16 +937,10 @@ allocate_barrier:
        spin_lock_irq(&mdev->tconn->req_lock);
 
        if (rw == WRITE) {
-               err = complete_conflicting_writes(mdev, sector, size);
-               if (err) {
-                       if (err != -ERESTARTSYS)
-                               _conn_request_state(mdev->tconn,
-                                                   NS(conn, C_TIMEOUT),
-                                                   CS_HARD);
-                       spin_unlock_irq(&mdev->tconn->req_lock);
-                       err = -EIO;
-                       goto fail_free_complete;
-               }
+               /* This may temporarily give up the req_lock,
+                * but will re-aquire it before it returns here.
+                * Needs to be before the check on drbd_suspended() */
+               complete_conflicting_writes(req);
        }
 
        if (drbd_suspended(mdev)) {