tdb: Clarify the CLEAR_IF_FIRST locked logic

This is another level of indentation, but it took me a while staring at the
if-condition to find that "locked" was assigned the result of "==0", not the
return value of tdb_nest_lock().

Best viewed with "git show -b".

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/lib/tdb/common/open.c b/lib/tdb/common/open.c
index f3ef856eae166874bb24d3dff6285a73e41eb88c..cfb476d2385fe8ddfdfa28672d10d9f292b8ab7b 100644 (file)
--- a/lib/tdb/common/open.c
+++ b/lib/tdb/common/open.c
@@ -300,7 +300,8 @@ _PUBLIC_ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int td
        struct tdb_header header;
        struct tdb_context *tdb;
        struct stat st;
-       int rev = 0, locked = 0;
+       int rev = 0;
+       bool locked = false;
        unsigned char *vp;
        uint32_t vertest;
        unsigned v;
@@ -512,37 +513,42 @@ _PUBLIC_ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int td
 
        /* we need to zero database if we are the only one with it open */
        if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
-           (!tdb->read_only) &&
-           (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
-               ret = tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0,
-                                TDB_LOCK_WAIT);
-               if (ret == -1) {
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
-                                "tdb_brlock failed for %s: %s\n",
-                                name, strerror(errno)));
-                       goto fail;
-               }
-               ret = tdb_new_database(tdb, &header, hash_size);
-               if (ret == -1) {
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
-                                "tdb_new_database failed for %s: %s\n",
-                                name, strerror(errno)));
-                       tdb_unlockall(tdb);
-                       goto fail;
-               }
-               ret = tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
-               if (ret == -1) {
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
-                                "tdb_unlockall failed for %s: %s\n",
-                                name, strerror(errno)));
-                       goto fail;
-               }
-               ret = lseek(tdb->fd, 0, SEEK_SET);
-               if (ret == -1) {
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
-                                "lseek failed for %s: %s\n",
-                                name, strerror(errno)));
-                       goto fail;
+           (!tdb->read_only)) {
+               ret = tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK,
+                                   TDB_LOCK_NOWAIT|TDB_LOCK_PROBE);
+               locked = (ret == 0);
+
+               if (locked) {
+                       ret = tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0,
+                                        TDB_LOCK_WAIT);
+                       if (ret == -1) {
+                               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+                                        "tdb_brlock failed for %s: %s\n",
+                                        name, strerror(errno)));
+                               goto fail;
+                       }
+                       ret = tdb_new_database(tdb, &header, hash_size);
+                       if (ret == -1) {
+                               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+                                        "tdb_new_database failed for "
+                                        "%s: %s\n", name, strerror(errno)));
+                               tdb_unlockall(tdb);
+                               goto fail;
+                       }
+                       ret = tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
+                       if (ret == -1) {
+                               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+                                        "tdb_unlockall failed for %s: %s\n",
+                                        name, strerror(errno)));
+                               goto fail;
+                       }
+                       ret = lseek(tdb->fd, 0, SEEK_SET);
+                       if (ret == -1) {
+                               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+                                        "lseek failed for %s: %s\n",
+                                        name, strerror(errno)));
+                               goto fail;
+                       }
                }
        }