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, 9 insertions, 9 deletions

diff --git a/lib/tdb/common/open.c b/lib/tdb/common/open.c
index 4d4f95a3daa..13d5c94e377 100644
--- a/lib/tdb/common/open.c
+++ b/lib/tdb/common/open.c
@@ -241,7 +241,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 
 	/* ensure there is only one process initialising at once */
-	if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) {
+	if (tdb->methods->brlock(tdb, F_WRLCK, GLOBAL_LOCK, 1, TDB_LOCK_WAIT) == -1) {
 		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get global lock on %s: %s\n",
 			 name, strerror(errno)));
 		goto fail;	/* errno set by tdb_brlock */
@@ -250,7 +250,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	/* 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->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0, 1) == 0))) {
+	    (locked = (tdb->methods->brlock(tdb, F_WRLCK, ACTIVE_LOCK, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
 		open_flags |= O_CREAT;
 		if (ftruncate(tdb->fd, 0) == -1) {
 			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
@@ -313,9 +313,9 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	tdb->inode = st.st_ino;
 	tdb_mmap(tdb);
 	if (locked) {
-		if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0, 1) == -1) {
+		if (tdb->methods->brunlock(tdb, F_WRLCK, ACTIVE_LOCK, 1) == -1) {
 			TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
-				 "failed to take ACTIVE_LOCK on %s: %s\n",
+				 "failed to release ACTIVE_LOCK on %s: %s\n",
 				 name, strerror(errno)));
 			goto fail;
 		}
@@ -328,7 +328,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 
 	if (tdb_flags & TDB_CLEAR_IF_FIRST) {
 		/* leave this lock in place to indicate it's in use */
-		if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)
+		if (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)
 			goto fail;
 	}
 
@@ -357,7 +357,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	/* Internal (memory-only) databases skip all the code above to
 	 * do with disk files, and resume here by releasing their
 	 * global lock and hooking into the active list. */
-	if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1) == -1)
+	if (tdb->methods->brunlock(tdb, F_WRLCK, GLOBAL_LOCK, 1) == -1)
 		goto fail;
 	tdb->next = tdbs;
 	tdbs = tdb;
@@ -407,10 +407,10 @@ int tdb_close(struct tdb_context *tdb)
 	struct tdb_context **i;
 	int ret = 0;
 
-	tdb_trace(tdb, "tdb_close");
 	if (tdb->transaction) {
-		_tdb_transaction_cancel(tdb);
+		tdb_transaction_cancel(tdb);
 	}
+	tdb_trace(tdb, "tdb_close");
 
 	if (tdb->map_ptr) {
 		if (tdb->flags & TDB_INTERNAL)
@@ -501,7 +501,7 @@ static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
 #endif /* fake pread or pwrite */
 
 	if (active_lock &&
-	    (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)) {
+	    (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)) {
 		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
 		goto fail;
 	}