From b7b73bc0c09f1b1d321c7aad3583b4b366207c7a Mon Sep 17 00:00:00 2001
From: Theodore Tso <tytso@mit.edu>
Date: Mon, 15 Oct 1990 16:53:21 +0000
Subject: [PATCH] Changes to export kdb5_db_lock and kdb5_db_unlock to the
 API.... changed the locking routines to allow recursive locks.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@1252 dc483132-0cff-0310-8789-dd5450dbe970
---
 src/lib/kdb/kdb_dbm.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/lib/kdb/kdb_dbm.c b/src/lib/kdb/kdb_dbm.c
index 964074af4..bc2fd26b0 100644
--- a/src/lib/kdb/kdb_dbm.c
+++ b/src/lib/kdb/kdb_dbm.c
@@ -38,6 +38,7 @@ extern int errno;
 
 static int dblfd = -1;
 static int mylock = 0;
+static int lockmode = 0;
 static int inited = 0;
 
 static char default_db_name[] = DEFAULT_DBM_FILE;
@@ -234,7 +235,7 @@ time_t *age;
     if (!okname)
 	return ENOMEM;
     if (stat (okname, &st) < 0)
-	*age = 0;
+	*age = -1;
     else
 	*age = st.st_mtime;
 
@@ -543,9 +544,10 @@ int mode;
 {
     int flock_mode;
 
-    if (mylock)				/* Detect lock call when lock already
-					 * locked */
-	return KRB5_KDB_RECURSIVELOCK;
+    if (mylock && (lockmode >= mode)) {
+	    mylock++;		/* No need to upgrade lock, just return */
+	    return(0);
+    }
 
     switch (mode) {
     case KRB5_DBM_EXCLUSIVE:
@@ -557,6 +559,7 @@ int mode;
     default:
 	return KRB5_KDB_BADLOCKMODE;
     }
+    lockmode = mode;
     if (non_blocking)
 	flock_mode |= LOCK_NB;
     
@@ -572,9 +575,10 @@ krb5_dbm_db_unlock()
     if (!mylock)		/* lock already unlocked */
 	return KRB5_KDB_NOTLOCKED;
 
-    if (flock(dblfd, LOCK_UN) < 0)
-	return errno;
-    mylock = 0;
+    if (--mylock) {
+	    if (flock(dblfd, LOCK_UN) < 0)
+		    return errno;
+    }
     return 0;
 }
 
-- 
2.26.2