From: Jeffrey Altman <jaltman@secure-endpoints.com>
Date: Wed, 23 Jul 2008 05:55:36 +0000 (+0000)
Subject: windows-volume-deadlock-20080722
X-Git-Tag: openafs-devel-1_5_61~944
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=2ed0ee573c2b36cc6979693827e36f1ce6bdfa1b;p=packages%2Fo%2Fopenafs.git

windows-volume-deadlock-20080722

LICENSE MIT

When updating the volume location information, if a new server must
be allocated and the server is down, then it is possible for a deadlock
to occur on the cm_volume_t rw lock.  Prevent that from happening.
---

diff --git a/src/WINNT/afsd/cm_volume.c b/src/WINNT/afsd/cm_volume.c
index cb3feb56a..3e181e57d 100644
--- a/src/WINNT/afsd/cm_volume.c
+++ b/src/WINNT/afsd/cm_volume.c
@@ -481,10 +481,13 @@ long cm_UpdateVolumeLocation(struct cm_cell *cellp, cm_user_t *userp, cm_req_t *
             tempAddr = htonl(serverNumber[i]);
             tsockAddr.sin_addr.s_addr = tempAddr;
             tsp = cm_FindServer(&tsockAddr, CM_SERVER_FILE);
-            if (!tsp)
-                tsp = cm_NewServer(&tsockAddr, CM_SERVER_FILE,
-                                    cellp, 0);
-
+            if (!tsp) {
+                /* cm_NewServer will probe the server which in turn will
+                 * update the state on the volume group object */
+                lock_ReleaseWrite(&volp->rw);
+                tsp = cm_NewServer(&tsockAddr, CM_SERVER_FILE, cellp, 0);
+                lock_ObtainWrite(&volp->rw);
+            }
             /* if this server was created by fs setserverprefs */
             if ( !tsp->cellp ) 
                 tsp->cellp = cellp;