drbd: Refuse to change network options online when...

* the peer does not speak protocol_version 100 and the
  user wants to change one of:
    - wire_protocol
    - two_primaries
    - integrity_alg

* the user wants to remove the allow_two_primaries flag
  when there are two primaries

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_nl.c b/drivers/block/drbd/drbd_nl.c
index 74c27f1..133a672 100644 (file)
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1722,10 +1722,24 @@ _check_net_options(struct drbd_tconn *tconn, struct net_conf *old_conf, struct n
        struct drbd_conf *mdev;
        int i;
 
-       if (old_conf && tconn->agreed_pro_version < 100 &&
-           tconn->cstate == C_WF_REPORT_PARAMS &&
-           new_conf->wire_protocol != old_conf->wire_protocol)
-               return ERR_NEED_APV_100;
+       if (old_conf && tconn->cstate == C_WF_REPORT_PARAMS && tconn->agreed_pro_version < 100) {
+               if (new_conf->wire_protocol != old_conf->wire_protocol)
+                       return ERR_NEED_APV_100;
+
+               if (new_conf->two_primaries != old_conf->two_primaries)
+                       return ERR_NEED_APV_100;
+
+               if (!new_conf->integrity_alg != !old_conf->integrity_alg)
+                       return ERR_NEED_APV_100;
+
+               if (strcmp(new_conf->integrity_alg, old_conf->integrity_alg))
+                       return ERR_NEED_APV_100;
+       }
+
+       if (!new_conf->two_primaries &&
+           conn_highest_role(tconn) == R_PRIMARY &&
+           conn_highest_peer(tconn) == R_PRIMARY)
+               return ERR_NEED_ALLOW_TWO_PRI;
 
        if (new_conf->two_primaries &&
            (new_conf->wire_protocol != DRBD_PROT_C))

diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 05063e6..679e811 100644 (file)
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -161,6 +161,7 @@ enum drbd_ret_code {
        ERR_MINOR_EXISTS        = 161,
        ERR_INVALID_REQUEST     = 162,
        ERR_NEED_APV_100        = 163,
+       ERR_NEED_ALLOW_TWO_PRI  = 164,
 
        /* insert new ones above this line */
        AFTER_LAST_ERR_CODE