s3: Add a "lock_order" argument to db_open

This will be used to enforce a lock hierarchy between the databases. We have
seen deadlocks between locking.tdb, brlock.tdb, serverid.tdb and notify*.tdb.
These should be fixed by refusing a dbwrap_fetch_locked that does not follow a
defined lock hierarchy.

6 files changed, 20 insertions, 10 deletions

diff --git a/source3/utils/dbwrap_tool.c b/source3/utils/dbwrap_tool.c
index 7850dc168e3..e178d5cc6ee 100644
--- a/source3/utils/dbwrap_tool.c
+++ b/source3/utils/dbwrap_tool.c
@@ -463,7 +463,8 @@ int main(int argc, const char **argv)
 		goto done;
 	}
 
-	db = db_open(mem_ctx, dbname, 0, TDB_DEFAULT, O_RDWR | O_CREAT, 0644);
+	db = db_open(mem_ctx, dbname, 0, TDB_DEFAULT, O_RDWR | O_CREAT, 0644,
+		     DBWRAP_LOCK_ORDER_1);
 	if (db == NULL) {
 		d_fprintf(stderr, "ERROR: could not open dbname\n");
 		goto done;
diff --git a/source3/utils/dbwrap_torture.c b/source3/utils/dbwrap_torture.c
index 9907f31f767..fb4ed6d4ec1 100644
--- a/source3/utils/dbwrap_torture.c
+++ b/source3/utils/dbwrap_torture.c
@@ -308,7 +308,8 @@ int main(int argc, const char *argv[])
 		tdb_flags |= TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH;
 	}
 
-	db = db_open(mem_ctx, db_name, 0, tdb_flags,  O_RDWR | O_CREAT, 0644);
+	db = db_open(mem_ctx, db_name, 0, tdb_flags,  O_RDWR | O_CREAT, 0644,
+		     DBWRAP_LOCK_ORDER_1);
 
 	if (db == NULL) {
 		d_fprintf(stderr, "failed to open db '%s': %s\n", db_name,
diff --git a/source3/utils/net_idmap.c b/source3/utils/net_idmap.c
index 3a3ae21f073..22734eecd81 100644
--- a/source3/utils/net_idmap.c
+++ b/source3/utils/net_idmap.c
@@ -131,7 +131,8 @@ static int net_idmap_dump(struct net_context *c, int argc, const char **argv)
 	}
 	d_fprintf(stderr, _("dumping id mapping from %s\n"), dbfile);
 
-	db = db_open(mem_ctx, dbfile, 0, TDB_DEFAULT, O_RDONLY, 0);
+	db = db_open(mem_ctx, dbfile, 0, TDB_DEFAULT, O_RDONLY, 0,
+		     DBWRAP_LOCK_ORDER_1);
 	if (db == NULL) {
 		d_fprintf(stderr, _("Could not open idmap db (%s): %s\n"),
 			  dbfile, strerror(errno));
@@ -240,7 +241,8 @@ static int net_idmap_restore(struct net_context *c, int argc, const char **argv)
 		input = stdin;
 	}
 
-	db = db_open(mem_ctx, dbfile, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0644);
+	db = db_open(mem_ctx, dbfile, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0644,
+		     DBWRAP_LOCK_ORDER_1);
 	if (db == NULL) {
 		d_fprintf(stderr, _("Could not open idmap db (%s): %s\n"),
 			  dbfile, strerror(errno));
@@ -444,7 +446,8 @@ static int net_idmap_delete(struct net_context *c, int argc, const char **argv)
 	}
 	d_fprintf(stderr, _("deleting id mapping from %s\n"), dbfile);
 
-	db = db_open(mem_ctx, dbfile, 0, TDB_DEFAULT, O_RDWR, 0);
+	db = db_open(mem_ctx, dbfile, 0, TDB_DEFAULT, O_RDWR, 0,
+		     DBWRAP_LOCK_ORDER_1);
 	if (db == NULL) {
 		d_fprintf(stderr, _("Could not open idmap db (%s): %s\n"),
 			  dbfile, strerror(errno));
@@ -616,7 +619,8 @@ static int net_idmap_aclmapset(struct net_context *c, int argc, const char **arg
 	}
 
 	if (!(db = db_open(mem_ctx, argv[0], 0, TDB_DEFAULT,
-			   O_RDWR|O_CREAT, 0600))) {
+			   O_RDWR|O_CREAT, 0600,
+			   DBWRAP_LOCK_ORDER_1))) {
 		d_fprintf(stderr, _("db_open failed: %s\n"), strerror(errno));
 		goto fail;
 	}
diff --git a/source3/utils/net_idmap_check.c b/source3/utils/net_idmap_check.c
index 3f9f3f53d96..1269410beec 100644
--- a/source3/utils/net_idmap_check.c
+++ b/source3/utils/net_idmap_check.c
@@ -804,7 +804,8 @@ static bool check_open_db(struct check_ctx* ctx, const char* name, int oflags)
 		}
 	}
 
-	ctx->db = db_open(ctx, name, 0, TDB_DEFAULT, oflags, 0);
+	ctx->db = db_open(ctx, name, 0, TDB_DEFAULT, oflags, 0,
+			  DBWRAP_LOCK_ORDER_1);
 	if (ctx->db == NULL) {
 		d_fprintf(stderr,
 			  _("Could not open idmap db (%s) for writing: %s\n"),
diff --git a/source3/utils/net_registry_check.c b/source3/utils/net_registry_check.c
index 201dc5ebc16..8d1a91c44b3 100644
--- a/source3/utils/net_registry_check.c
+++ b/source3/utils/net_registry_check.c
@@ -354,7 +354,8 @@ static bool check_ctx_open_output(struct check_ctx *ctx)
 		ctx->opt.wipe = true;
 	}
 
-	ctx->odb = db_open(ctx, ctx->opt.output, 0, TDB_DEFAULT, oflags, 0644);
+	ctx->odb = db_open(ctx, ctx->opt.output, 0, TDB_DEFAULT, oflags, 0644,
+			   DBWRAP_LOCK_ORDER_1);
 	if (ctx->odb == NULL) {
 		d_fprintf(stderr,
 			  _("Could not open db (%s) for writing: %s\n"),
@@ -366,7 +367,8 @@ static bool check_ctx_open_output(struct check_ctx *ctx)
 
 
 static bool check_ctx_open_input(struct check_ctx *ctx) {
-	ctx->idb = db_open(ctx, ctx->fname, 0, TDB_DEFAULT, O_RDONLY, 0);
+	ctx->idb = db_open(ctx, ctx->fname, 0, TDB_DEFAULT, O_RDONLY, 0,
+			   DBWRAP_LOCK_ORDER_1);
 	if (ctx->idb == NULL) {
 		d_fprintf(stderr,
 			  _("Could not open db (%s) for reading: %s\n"),
diff --git a/source3/utils/status.c b/source3/utils/status.c
index 8ae8de76a34..8f8f3945cbf 100644
--- a/source3/utils/status.c
+++ b/source3/utils/status.c
@@ -455,7 +455,8 @@ static int traverse_sessionid(const char *key, struct sessionid *session,
 		int result;
 		struct db_context *db;
 		db = db_open(NULL, lock_path("locking.tdb"), 0,
-			     TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH, O_RDONLY, 0);
+			     TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH, O_RDONLY, 0,
+			     DBWRAP_LOCK_ORDER_1);
 
 		if (!db) {
 			d_printf("%s not initialised\n",