From 45e61fcf61ed9863fbe2b116fe0763fc139bbe0d Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Fri, 6 Jan 2012 17:19:54 +0100 Subject: 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. --- source3/lib/dbwrap/dbwrap_open.c | 19 +++++++++++++++++-- source3/lib/dbwrap/dbwrap_open.h | 8 +++++++- source3/lib/dbwrap/dbwrap_private.h | 2 ++ 3 files changed, 26 insertions(+), 3 deletions(-) (limited to 'source3/lib/dbwrap') diff --git a/source3/lib/dbwrap/dbwrap_open.c b/source3/lib/dbwrap/dbwrap_open.c index 6b8be2de16..23d299511b 100644 --- a/source3/lib/dbwrap/dbwrap_open.c +++ b/source3/lib/dbwrap/dbwrap_open.c @@ -62,11 +62,26 @@ bool db_is_local(const char *name) struct db_context *db_open(TALLOC_CTX *mem_ctx, const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode) + int open_flags, mode_t mode, + enum dbwrap_lock_order lock_order) { struct db_context *result = NULL; #ifdef CLUSTER_SUPPORT - const char *sockname = lp_ctdbd_socket(); + const char *sockname; +#endif + + if ((lock_order != DBWRAP_LOCK_ORDER_1) && + (lock_order != DBWRAP_LOCK_ORDER_2)) { + /* + * Only allow 2 levels. ctdb gives us 3, and we will + * have the watchers database soon. + */ + errno = EINVAL; + return NULL; + } + +#ifdef CLUSTER_SUPPORT + sockname = lp_ctdbd_socket(); if(!sockname || !*sockname) { sockname = CTDB_PATH; diff --git a/source3/lib/dbwrap/dbwrap_open.h b/source3/lib/dbwrap/dbwrap_open.h index 5a172a4a2a..2763ef2ade 100644 --- a/source3/lib/dbwrap/dbwrap_open.h +++ b/source3/lib/dbwrap/dbwrap_open.h @@ -29,6 +29,11 @@ struct db_context; */ bool db_is_local(const char *name); +enum dbwrap_lock_order { + DBWRAP_LOCK_ORDER_1 = 1, + DBWRAP_LOCK_ORDER_2 = 2 +}; + /** * Convenience function that will determine whether to * open a tdb database via the tdb backend or via the ctdb @@ -38,6 +43,7 @@ bool db_is_local(const char *name); struct db_context *db_open(TALLOC_CTX *mem_ctx, const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode); + int open_flags, mode_t mode, + enum dbwrap_lock_order lock_order); #endif /* __DBWRAP_OPEN_H__ */ diff --git a/source3/lib/dbwrap/dbwrap_private.h b/source3/lib/dbwrap/dbwrap_private.h index 4806618543..d0b3279368 100644 --- a/source3/lib/dbwrap/dbwrap_private.h +++ b/source3/lib/dbwrap/dbwrap_private.h @@ -23,6 +23,8 @@ #ifndef __DBWRAP_PRIVATE_H__ #define __DBWRAP_PRIVATE_H__ +#include "dbwrap/dbwrap_open.h" + struct db_record { TDB_DATA key, value; NTSTATUS (*store)(struct db_record *rec, TDB_DATA data, int flag); -- cgit