drbd: Adding support for BIO/Request flags: REQ_FUA, REQ_FLUSH and REQ_DISCARD

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

3 files changed, 34 insertions, 22 deletions

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index f9b75fc30569..79b877db9a39 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -374,9 +374,13 @@ union p_header {
  */
 
 /* these defines must not be changed without changing the protocol version */
-#define DP_HARDBARRIER        1
-#define DP_RW_SYNC            2
+#define DP_HARDBARRIER        1 /* depricated */
+#define DP_RW_SYNC            2 /* equals REQ_SYNC    */
 #define DP_MAY_SET_IN_SYNC    4
+#define DP_UNPLUG             8 /* equals REQ_UNPLUG  */
+#define DP_FUA               16 /* equals REQ_FUA     */
+#define DP_FLUSH             32 /* equals REQ_FLUSH   */
+#define DP_DISCARD           64 /* equals REQ_DISCARD */
 
 struct p_data {
         union p_header head;
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index ab1244e0045c..1827cf073c2e 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2426,6 +2426,18 @@ static int _drbd_send_zc_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e)
         return 1;
 }
 
+static u32 bio_flags_to_wire(struct drbd_conf *mdev, unsigned long bi_rw)
+{
+        if (mdev->agreed_pro_version >= 95)
+                return  (bi_rw & REQ_SYNC ? DP_RW_SYNC : 0) |
+                        (bi_rw & REQ_UNPLUG ? DP_UNPLUG : 0) |
+                        (bi_rw & REQ_FUA ? DP_FUA : 0) |
+                        (bi_rw & REQ_FLUSH ? DP_FLUSH : 0) |
+                        (bi_rw & REQ_DISCARD ? DP_DISCARD : 0);
+        else
+                return bi_rw & (REQ_SYNC | REQ_UNPLUG) ? DP_RW_SYNC : 0;
+}
+
 /* Used to send write requests
  * R_PRIMARY -> Peer    (P_DATA)
  */
@@ -2459,21 +2471,9 @@ int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
         p.block_id = (unsigned long)req;
         p.seq_num  = cpu_to_be32(req->seq_num =
                                  atomic_add_return(1, &mdev->packet_seq));
-        dp_flags = 0;
 
-        /* NOTE: no need to check if barriers supported here as we would
-         *       not pass the test in make_request_common in that case
-         */
-        if (req->master_bio->bi_rw & REQ_HARDBARRIER) {
-                dev_err(DEV, "ASSERT FAILED would have set DP_HARDBARRIER\n");
-                /* dp_flags |= DP_HARDBARRIER; */
-        }
-        if (req->master_bio->bi_rw & REQ_SYNC)
-                dp_flags |= DP_RW_SYNC;
-        /* for now handle SYNCIO and UNPLUG
-         * as if they still were one and the same flag */
-        if (req->master_bio->bi_rw & REQ_UNPLUG)
-                dp_flags |= DP_RW_SYNC;
+        dp_flags = bio_flags_to_wire(mdev, req->master_bio->bi_rw);
+
         if (mdev->state.conn >= C_SYNC_SOURCE &&
             mdev->state.conn <= C_PAUSED_SYNC_T)
                 dp_flags |= DP_MAY_SET_IN_SYNC;
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 885471ded2fb..e96fbb04ea4d 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1753,6 +1753,18 @@ static int drbd_wait_peer_seq(struct drbd_conf *mdev, const u32 packet_seq)
         return ret;
 }
 
+static unsigned long write_flags_to_bio(struct drbd_conf *mdev, u32 dpf)
+{
+        if (mdev->agreed_pro_version >= 95)
+                return  (dpf & DP_RW_SYNC ? REQ_SYNC : 0) |
+                        (dpf & DP_UNPLUG ? REQ_UNPLUG : 0) |
+                        (dpf & DP_FUA ? REQ_FUA : 0) |
+                        (dpf & DP_FLUSH ? REQ_FUA : 0) |
+                        (dpf & DP_DISCARD ? REQ_DISCARD : 0);
+        else
+                return dpf & DP_RW_SYNC ? (REQ_SYNC | REQ_UNPLUG) : 0;
+}
+
 /* mirrored write */
 static int receive_Data(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
 {
@@ -1818,12 +1830,8 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned
         spin_unlock(&mdev->epoch_lock);
 
         dp_flags = be32_to_cpu(p->dp_flags);
-        if (dp_flags & DP_HARDBARRIER) {
-                dev_err(DEV, "ASSERT FAILED would have submitted barrier request\n");
-                /* rw |= REQ_HARDBARRIER; */
-        }
-        if (dp_flags & DP_RW_SYNC)
-                rw |= REQ_SYNC | REQ_UNPLUG;
+        rw |= write_flags_to_bio(mdev, dp_flags);
+
         if (dp_flags & DP_MAY_SET_IN_SYNC)
                 e->flags |= EE_MAY_SET_IN_SYNC;