Windows: out of order lock smb v3 locking

Do not obtain the smb_rctLock after holding the cm_scache_t->rw
lock.

At most one hold is required in case of lock failure.  Obtain
it as the start of processing and drop it at the end if not required.

Reviewed-on: http://gerrit.openafs.org/4955
Tested-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
(cherry picked from commit da6c97678f530ca76334613e229337a75f94e297)

Change-Id: I6b530366c74fd45ba585fd7af4615a1dc96ac055
Reviewed-on: http://gerrit.openafs.org/4960
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>

diff --git a/src/WINNT/afsd/smb3.c b/src/WINNT/afsd/smb3.c
index 0d6e5841c74d27193374a82aa3a6b9526e11dac5..8f1467849349c6c31e6ab649acd4f955d4934e2f 100644 (file)
--- a/src/WINNT/afsd/smb3.c
+++ b/src/WINNT/afsd/smb3.c
@@ -6584,6 +6584,7 @@ long smb_ReceiveV3LockingX(smb_vc_t *vcp, smb_packet_t *inp, smb_packet_t *outp)
     int i;
     cm_key_t key;
     unsigned int pid;
+    afs_uint32 smb_vc_hold_required = 0;
 
     smb_InitReq(&req);
 
@@ -6619,6 +6620,7 @@ long smb_ReceiveV3LockingX(smb_vc_t *vcp, smb_packet_t *inp, smb_packet_t *outp)
     inp->fid = fid;
 
     userp = smb_GetUserFromVCP(vcp, inp);
+    smb_HoldVC(vcp);
 
     lock_ObtainWrite(&scp->rw);
     code = cm_SyncOp(scp, NULL, userp, &req, 0,
@@ -6725,7 +6727,7 @@ long smb_ReceiveV3LockingX(smb_vc_t *vcp, smb_packet_t *inp, smb_packet_t *outp)
                 osi_assertx(wlRequest != NULL, "null wlRequest");
 
                 wlRequest->vcp = vcp;
-                smb_HoldVC(vcp);
+                smb_vc_hold_required = 1;
                 wlRequest->scp = scp;
                osi_Log2(smb_logp,"smb_ReceiveV3LockingX wlRequest 0x%p scp 0x%p", wlRequest, scp);
                 cm_HoldSCache(scp);
@@ -6857,6 +6859,8 @@ long smb_ReceiveV3LockingX(smb_vc_t *vcp, smb_packet_t *inp, smb_packet_t *outp)
     cm_ReleaseSCache(scp);
     cm_ReleaseUser(userp);
     smb_ReleaseFID(fidp);
+    if (!smb_vc_hold_required)
+        smb_HoldVC(vcp);
 
     return code;
 }