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, 25 insertions, 1 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 7d359863ae32..106b9abdc430 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -925,7 +925,12 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state
         if (fp == FP_STONITH &&
             (ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.pdsk > D_OUTDATED) &&
             !(os.role == R_PRIMARY && os.conn < C_CONNECTED && os.pdsk > D_OUTDATED))
-                ns.susp = 1;
+                ns.susp = 1; /* Suspend IO while fence-peer handler runs (peer lost) */
+
+        if (mdev->sync_conf.on_no_data == OND_SUSPEND_IO &&
+            (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE) &&
+            !(os.role == R_PRIMARY && os.disk < D_UP_TO_DATE && os.pdsk < D_UP_TO_DATE))
+                ns.susp = 1; /* Suspend IO while no data available (no accessible data available) */
 
         if (ns.aftr_isp || ns.peer_isp || ns.user_isp) {
                 if (ns.conn == C_SYNC_SOURCE)
@@ -1236,6 +1241,25 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
         /* Here we have the actions that are performed after a
            state change. This function might sleep */
 
+        if (os.susp && ns.susp && mdev->sync_conf.on_no_data == OND_SUSPEND_IO) {
+                if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED) {
+                        if (ns.conn == C_CONNECTED) {
+                                spin_lock_irq(&mdev->req_lock);
+                                _tl_restart(mdev, resend);
+                                _drbd_set_state(_NS(mdev, susp, 0), CS_VERBOSE, NULL);
+                                spin_unlock_irq(&mdev->req_lock);
+                        } else /* ns.conn > C_CONNECTED */
+                                dev_err(DEV, "Unexpected Resynd going on!\n");
+                }
+
+                if (os.disk == D_ATTACHING && ns.disk > D_ATTACHING) {
+                        spin_lock_irq(&mdev->req_lock);
+                        _tl_restart(mdev, restart_frozen_disk_io);
+                        _drbd_set_state(_NS(mdev, susp, 0), CS_VERBOSE, NULL);
+                        spin_unlock_irq(&mdev->req_lock);
+                }
+        }
+
         if (fp == FP_STONITH && ns.susp) {
                 /* case1: The outdate peer handler is successful:
                  * case2: The connection was established again: */