From: Jeffrey Altman <jaltman@your-file-system.com>
Date: Thu, 23 Jan 2014 03:17:56 +0000 (-0500)
Subject: Windows: cm_GetCell_gen Fixup cm_server cellp on race
X-Git-Tag: upstream/1.8.0_pre1^2~789
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=3e4af71581fa8d174a0127bb225e7fba2450aaae;p=packages%2Fo%2Fopenafs.git

Windows: cm_GetCell_gen Fixup cm_server cellp on race

If a race occurs during the instantiation of a new cm_cell_t object,
the created servers will point at the wrong cm_cell_t object after
the race is detected.  Before cm_GetCell_gen completes the cm_server_t
objects must be fixed to point to the correct cm_cell_t.

Change-Id: I8341c2cfd2a8ac7be31699d11f78b4b9ced257af
Reviewed-on: http://gerrit.openafs.org/10777
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
---

diff --git a/src/WINNT/afsd/cm_cell.c b/src/WINNT/afsd/cm_cell.c
index 990584b77..b552a3b88 100644
--- a/src/WINNT/afsd/cm_cell.c
+++ b/src/WINNT/afsd/cm_cell.c
@@ -342,6 +342,8 @@ cm_cell_t *cm_GetCell_Gen(char *namep, char *newnamep, afs_uint32 flags)
         }
 
         if (cp2) {
+	    cm_server_t *tsp;
+
             if (!hasMutex) {
                 lock_ObtainMutex(&cp->mx);
                 hasMutex = 1;
@@ -352,7 +354,24 @@ cm_cell_t *cm_GetCell_Gen(char *namep, char *newnamep, afs_uint32 flags)
             cm_RemoveCellFromNameHashTable(cp);
             lock_ReleaseMutex(&cp->mx);
             hasMutex = 0;
-            cm_FreeCell(cp);
+
+	    /* Replace cells references in servers */
+	    lock_ObtainRead(&cm_serverLock);
+	    for (tsp = cm_serversAllFirstp;
+		  tsp;
+		  tsp = (cm_server_t *)osi_QNext(&tsp->allq)) {
+		if (tsp->cellp == cp) {
+		    osi_Log4(afsd_logp, "cm_GetCell_gen race: replacing cell (%u) %s with cell (%u) %s",
+			      cp->cellID,
+			      osi_LogSaveString(afsd_logp,cp->name),
+			      cp2->cellID,
+			      osi_LogSaveString(afsd_logp,cp2->name));
+		    tsp->cellp = cp2;
+		}
+	    }
+	    lock_ReleaseRead(&cm_serverLock);
+
+	    cm_FreeCell(cp);
             cp = cp2;
             goto done;
         }