[SCM] CTDB repository - branch master updated - ctdb-1.0.114-154-g2f6a870

[Ronnie Sahlberg]

The branch, master has been updated
       via  2f6a870d7ff02ceb61fde242f752dccbfcb4cb37 (commit)
      from  9b4a83e49c5df80df8498b7384c5f53f390c1d9d (commit)

http://gitweb.samba.org/?p=sahlberg/ctdb.git;a=shortlog;h=master


- Log -----------------------------------------------------------------
commit 2f6a870d7ff02ceb61fde242f752dccbfcb4cb37
Author: Ronnie Sahlberg <ronniesahlberg at gmail.com>
Date:   Wed Jun 9 16:12:36 2010 +1000

    idr can timeout and wrap/be reused quite quickly.
    
    If a noremote node hangs for an extended period, it is possible
    that we might have a DMASTER request in flight for record A to that node.
    Eventually we will reuse the idr, and may reuse it for a DMASTER request to a different node for a different record B.
    
    If while the request for B is in flight,  the first tnode un-hangs and responds back
    we would receive a dmaster reply for the wrong record.
    
    This would cause a record to become perpetually locked, since inside the daemon we would tdb_chainlock(dmaster_reply->pdu->key)   but once the migration would complete we would chainunlock   idr->state->call->key
    
    Adding code to verify that when we receive a dmaster reply packet that it does in fact match the exact same key that the state variable we have for the idr in flight.

-----------------------------------------------------------------------

Summary of changes:
 server/ctdb_call.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)


Changeset truncated at 500 lines:

diff --git a/server/ctdb_call.c b/server/ctdb_call.c
index 6ef73fe..b6af807 100644
--- a/server/ctdb_call.c
+++ b/server/ctdb_call.c
@@ -276,6 +276,16 @@ static void ctdb_become_dmaster(struct ctdb_db_context *ctdb_db,
 		return;
 	}
 
+	if (key.dsize != state->call->key.dsize || memcmp(key.dptr, state->call->key.dptr, key.dsize)) {
+		DEBUG(DEBUG_ERR, ("Got bogus DMASTER packet reqid:%u\n from node %u. Key does not match key held in matching idr.", hdr->reqid, hdr->srcnode));
+
+		ret = ctdb_ltdb_unlock(ctdb_db, key);
+		if (ret != 0) {
+			DEBUG(DEBUG_ERR,(__location__ " ctdb_ltdb_unlock() failed with error %d\n", ret));
+		}
+		return;
+	}
+
 	if (hdr->reqid != state->reqid) {
 		/* we found a record  but it was the wrong one */
 		DEBUG(DEBUG_ERR, ("Dropped orphan in ctdb_become_dmaster with reqid:%u\n from node %u", hdr->reqid, hdr->srcnode));
@@ -289,7 +299,7 @@ static void ctdb_become_dmaster(struct ctdb_db_context *ctdb_db,
 
 	ctdb_call_local(ctdb_db, state->call, &header, state, &data, ctdb->pnn);
 
-	ret = ctdb_ltdb_unlock(ctdb_db, key);
+	ret = ctdb_ltdb_unlock(ctdb_db, state->call->key);
 	if (ret != 0) {
 		DEBUG(DEBUG_ERR,(__location__ " ctdb_ltdb_unlock() failed with error %d\n", ret));
 	}


-- 
CTDB repository