windows-smb-vcp-cleanup-races-20060511

Only allow one thread to mark the vcp dead

diff --git a/src/WINNT/afsd/smb.c b/src/WINNT/afsd/smb.c
index 9ae605277d8653ce0f3681895f4f24ce33bb7303..5423c20099444d0e88fb226c14f63514808cb27c 100644 (file)
--- a/src/WINNT/afsd/smb.c
+++ b/src/WINNT/afsd/smb.c
@@ -2525,16 +2525,19 @@ void smb_SendPacket(smb_vc_t *vcp, smb_packet_t *inp)
        LogEvent(EVENTLOG_WARNING_TYPE, MSG_SMB_SEND_PACKET_FAILURE, s);
 #endif /* !DJGPP */
 
-       osi_Log2(smb_logp, "marking dead vcp 0x%x, user struct 0x%x",
-                vcp, vcp->usersp);
-
-       lock_ObtainMutex(&vcp->mx);
-       vcp->flags |= SMB_VCFLAG_ALREADYDEAD;
-       lock_ReleaseMutex(&vcp->mx);
-       lock_ObtainWrite(&smb_globalLock);
-       dead_sessions[vcp->session] = TRUE;
-       lock_ReleaseWrite(&smb_globalLock);
-       smb_CleanupDeadVC(vcp);
+       lock_ObtainMutex(&vcp->mx);
+       if (!(vcp->flags & SMB_VCFLAG_ALREADYDEAD)) {
+           osi_Log2(smb_logp, "marking dead vcp 0x%x, user struct 0x%x",
+                     vcp, vcp->usersp);
+           vcp->flags |= SMB_VCFLAG_ALREADYDEAD;
+           lock_ReleaseMutex(&vcp->mx);
+           lock_ObtainWrite(&smb_globalLock);
+           dead_sessions[vcp->session] = TRUE;
+           lock_ReleaseWrite(&smb_globalLock);
+           smb_CleanupDeadVC(vcp);
+       } else {
+           lock_ReleaseMutex(&vcp->mx);
+       }
     }
 
     if (localNCB)
@@ -8111,9 +8114,18 @@ void smb_Listener(void *parmp)
             smb_FreePacket(outp);
 
            lock_ObtainMutex(&vcp->mx);
-           vcp->flags |= SMB_VCFLAG_ALREADYDEAD;
-           lock_ReleaseMutex(&vcp->mx);
-           smb_CleanupDeadVC(vcp);
+           if (!(vcp->flags & SMB_VCFLAG_ALREADYDEAD)) {
+               osi_Log2(smb_logp, "marking dead vcp 0x%x, user struct 0x%x",
+                         vcp, vcp->usersp);
+               vcp->flags |= SMB_VCFLAG_ALREADYDEAD;
+               lock_ReleaseMutex(&vcp->mx);
+               lock_ObtainWrite(&smb_globalLock);
+               dead_sessions[vcp->session] = TRUE;
+               lock_ReleaseWrite(&smb_globalLock);
+               smb_CleanupDeadVC(vcp);
+           } else {
+               lock_ReleaseMutex(&vcp->mx);
+           }
         } else {
             /* assert that we do not exceed the maximum number of sessions or NCBs.
              * we should probably want to wait for a session to be freed in case