drbd: factored tl_restart() out of tl_clear().

If IO was frozen for a temporal network outage, resend the
content of the transfer-log into the newly established connection.

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

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index db37c6e47fa9..1bcb85539735 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -104,6 +104,7 @@ enum drbd_req_event {
         read_ahead_completed_with_error,
         write_completed_with_error,
         completed_ok,
+        resend,
         nothing, /* for tracing only */
 };
 
@@ -206,6 +207,13 @@ enum drbd_req_state_bits {
 
 #define RQ_WRITE           (1UL << __RQ_WRITE)
 
+/* For waking up the frozen transfer log mod_req() has to return if the request
+   should be counted in the epoch object*/
+#define MR_WRITE_SHIFT 0
+#define MR_WRITE       (1 << MR_WRITE_SHIFT)
+#define MR_READ_SHIFT  1
+#define MR_READ        (1 << MR_READ_SHIFT)
+
 /* epoch entries */
 static inline
 struct hlist_head *ee_hash_slot(struct drbd_conf *mdev, sector_t sector)