tdb: cleanup: split brlock and brunlock methods.

This is taken from the CCAN code base: rather than using tdb_brlock for
locking and unlocking, we split it into brlock and brunlock functions.

For extra debugging information, brunlock says what kind of lock it is
unlocking (even though fnctl locks don't need this).  This requires an
extra argument to tdb_transaction_unlock() so we know whether the
lock was upgraded to a write lock or not.

We also use a "flags" argument tdb_brlock:
1) TDB_LOCK_NOWAIT replaces lck_type = F_SETLK (vs F_SETLKW).
2) TDB_LOCK_MARK_ONLY replaces setting TDB_MARK_LOCK bit in ltype.
3) TDB_LOCK_PROBE replaces the "probe" argument.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/tdb/common/traverse.c b/lib/tdb/common/traverse.c
index c340dd354b..d329ef4da4 100644
--- a/lib/tdb/common/traverse.c
+++ b/lib/tdb/common/traverse.c
@@ -229,7 +229,7 @@ int tdb_traverse_read(struct tdb_context *tdb,
 	ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
 	tdb->traverse_read--;
 
-	tdb_transaction_unlock(tdb);
+	tdb_transaction_unlock(tdb, F_RDLCK);
 
 	return ret;
 }
@@ -260,7 +260,7 @@ int tdb_traverse(struct tdb_context *tdb,
 	ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
 	tdb->traverse_write--;
 
-	tdb_transaction_unlock(tdb);
+	tdb_transaction_unlock(tdb, F_WRLCK);
 
 	return ret;
 }