afs: Panic on afs_conn refcount imbalance

An undercounted afs_conn can easily cause a panic and/or memory
corruption later on, since we put an rx_connection reference with each
afs_conn reference. Panic as soon as we detect this, as this indicates
a serious bug.

Reviewed-on: http://gerrit.openafs.org/6413
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit 8a574ba16a80fc2b8b703ddcfc99486b977e6071)

Change-Id: Ibd60dafdf1a800349b73754dae18666fa0edd300
Reviewed-on: http://gerrit.openafs.org/6642
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>

diff --git a/src/afs/afs_conn.c b/src/afs/afs_conn.c
index cbe1fcbaf3937fdfa192644c30320a0b825be2e2..95baf6c4a13f7f9c23e82f1cf2470be12b30cbec 100644 (file)
--- a/src/afs/afs_conn.c
+++ b/src/afs/afs_conn.c
@@ -479,6 +479,10 @@ afs_PutConn(struct afs_conn *ac, struct rx_connection *rxconn,
 {
     AFS_STATCNT(afs_PutConn);
     ac->refCount--;
+    if (ac->refCount < 0) {
+       osi_Panic("afs_PutConn: refcount imbalance 0x%lx %d",
+                 (unsigned long)(uintptrsz)ac, (int)ac->refCount);
+    }
     rx_PutConnection(rxconn);
 }                              /*afs_PutConn */