s3 BRL: Add more clarifying comments and add implied logic to make conditional more...

diff --git a/source3/locking/brlock.c b/source3/locking/brlock.c
index d12c4affc38f946358831d2f4ddfc17933959797..aa522ac7801ebc77f34c51f0760f9bfaa28be9ab 100644 (file)
--- a/source3/locking/brlock.c
+++ b/source3/locking/brlock.c
@@ -74,6 +74,7 @@ bool brl_same_context(const struct lock_context *ctx1,
 static bool brl_overlap(const struct lock_struct *lck1,
                         const struct lock_struct *lck2)
 {
+       /* XXX Remove for Win7 compatibility. */
        /* this extra check is not redundent - it copes with locks
           that go beyond the end of 64 bit file space */
        if (lck1->size != 0 &&
@@ -105,8 +106,11 @@ static bool brl_conflict(const struct lock_struct *lck1,
                return False;
        }
 
-       if (brl_same_context(&lck1->context, &lck2->context) &&
-           lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
+       /* A READ lock can stack on top of a WRITE lock if they have the same
+        * context & fnum. */
+       if (lck1->lock_type == WRITE_LOCK && lck2->lock_type == READ_LOCK &&
+           brl_same_context(&lck1->context, &lck2->context) &&
+           lck1->fnum == lck2->fnum) {
                return False;
        }