drbd: Allow volumes to become primary only on one side

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_state.c b/drivers/block/drbd/drbd_state.c
index 886b996ec7b383a2c5753f94d990ccbad26d215a..11685658659e56ea58c5db7e8780e2da0e09117c 100644 (file)
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -329,6 +329,18 @@ static void print_state_change(struct drbd_conf *mdev, union drbd_state os, unio
                dev_info(DEV, "%s\n", pb);
 }
 
+static bool vol_has_primary_peer(struct drbd_tconn *tconn)
+{
+       struct drbd_conf *mdev;
+       int minor;
+
+       idr_for_each_entry(&tconn->volumes, mdev, minor) {
+               if (mdev->state.peer == R_PRIMARY)
+                       return true;
+       }
+       return false;
+}
+
 /**
  * is_valid_state() - Returns an SS_ error code if ns is not valid
  * @mdev:      DRBD device.
@@ -349,9 +361,12 @@ is_valid_state(struct drbd_conf *mdev, union drbd_state ns)
        }
 
        if (get_net_conf(mdev->tconn)) {
-               if (!mdev->tconn->net_conf->two_primaries &&
-                   ns.role == R_PRIMARY && ns.peer == R_PRIMARY)
-                       rv = SS_TWO_PRIMARIES;
+               if (!mdev->tconn->net_conf->two_primaries && ns.role == R_PRIMARY) {
+                       if (ns.peer == R_PRIMARY)
+                               rv = SS_TWO_PRIMARIES;
+                       else if (vol_has_primary_peer(mdev->tconn))
+                               rv = SS_O_VOL_PEER_PRI;
+                       }
                put_net_conf(mdev->tconn);
        }
 

diff --git a/drivers/block/drbd/drbd_strings.c b/drivers/block/drbd/drbd_strings.c
index c44a2a6027724ddaf373664728bf6b2b592b68b7..9a664bd27404b87336247d452e736650f7476deb 100644 (file)
--- a/drivers/block/drbd/drbd_strings.c
+++ b/drivers/block/drbd/drbd_strings.c
@@ -89,6 +89,7 @@ static const char *drbd_state_sw_errors[] = {
        [-SS_LOWER_THAN_OUTDATED] = "Disk state is lower than outdated",
        [-SS_IN_TRANSIENT_STATE] = "In transient state, retry after next state change",
        [-SS_CONCURRENT_ST_CHG] = "Concurrent state changes detected and aborted",
+       [-SS_O_VOL_PEER_PRI] = "Other vol primary on peer not allowed by config",
 };
 
 const char *drbd_conn_str(enum drbd_conns s)

diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index d28fdd8fcd4905e64d3ed586a79813ffd554487a..9cdb888607ae9148e67f9170584bed10600884a7 100644 (file)
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -300,7 +300,8 @@ enum drbd_state_rv {
        SS_NOT_SUPPORTED = -17,      /* drbd-8.2 only */
        SS_IN_TRANSIENT_STATE = -18,  /* Retry after the next state change */
        SS_CONCURRENT_ST_CHG = -19,   /* Concurrent cluster side state change! */
-       SS_AFTER_LAST_ERROR = -20,    /* Keep this at bottom */
+       SS_O_VOL_PEER_PRI = -20,
+       SS_AFTER_LAST_ERROR = -21,    /* Keep this at bottom */
 };
 
 /* from drbd_strings.c */