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| author | Ronnie Sahlberg <ronniesahlberg@gmail.com> | 2009-05-25 17:04:42 +1000 |
|---|---|---|
| committer | Stefan Metzmacher <metze@samba.org> | 2009-11-20 09:45:34 +0100 |
| commit | 436b55db1ff238ec467b07a74b088f6fcfaf927c (patch) | |
| tree | 1689f28b11031276ec4b9ce95509e5a780de4c9a | |
| parent | 85449b7bcc4bd7948bea38b5514a02357950a002 (diff) | |
| download | samba-436b55db1ff238ec467b07a74b088f6fcfaf927c.tar.gz samba-436b55db1ff238ec467b07a74b088f6fcfaf927c.tar.bz2 samba-436b55db1ff238ec467b07a74b088f6fcfaf927c.zip | |
New attempt at TDB transaction nesting allow/disallow.
Make the default be that transaction is not allowed and any attempt to create a nested transaction will fail with TDB_ERR_NESTING.
If an application can cope with transaction nesting and the implicit
semantics of tdb_transaction_commit(), it can enable transaction nesting
by using the TDB_ALLOW_NESTING flag.
(cherry picked from ctdb commit 3e49e41c21eb8c53084aa8cc7fd3557bdd8eb7b6)
Signed-off-by: Stefan Metzmacher <metze@samba.org>
| -rw-r--r-- | lib/tdb/common/transaction.c | 11 | ||||
| -rw-r--r-- | lib/tdb/include/tdb.h | 4 |
2 files changed, 14 insertions, 1 deletions
diff --git a/lib/tdb/common/transaction.c b/lib/tdb/common/transaction.c index 035b4e1d54..501cd62b96 100644 --- a/lib/tdb/common/transaction.c +++ b/lib/tdb/common/transaction.c @@ -85,6 +85,13 @@ still available, but no transaction recovery area is used and no fsync/msync calls are made. + - if TDB_ALLOW_NESTING is passed to flags in tdb open, or added using + tdb_add_flags() transaction is enabled. + The default is that transaction nesting is not allowed and an attempt + to create a nested transaction will fail with TDB_ERR_NESTING. + + Beware. when transactions are nested a transaction successfully + completed with tdb_transaction_commit() can be silently unrolled later. */ @@ -427,6 +434,10 @@ int tdb_transaction_start(struct tdb_context *tdb) /* cope with nested tdb_transaction_start() calls */ if (tdb->transaction != NULL) { + if (!(tdb->flags & TDB_ALLOW_NESTING)) { + tdb->ecode = TDB_ERR_NESTING; + return -1; + } tdb->transaction->nesting++; TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_start: nesting %d\n", tdb->transaction->nesting)); diff --git a/lib/tdb/include/tdb.h b/lib/tdb/include/tdb.h index e849f20641..5cc1eecdd1 100644 --- a/lib/tdb/include/tdb.h +++ b/lib/tdb/include/tdb.h @@ -48,11 +48,13 @@ extern "C" { #define TDB_NOSYNC 64 /* don't use synchronous transactions */ #define TDB_SEQNUM 128 /* maintain a sequence number */ #define TDB_VOLATILE 256 /* Activate the per-hashchain freelist, default 5 */ +#define TDB_ALLOW_NESTING 512 /* Allow transactions to nest */ /* error codes */ enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK, TDB_ERR_OOM, TDB_ERR_EXISTS, TDB_ERR_NOLOCK, TDB_ERR_LOCK_TIMEOUT, - TDB_ERR_NOEXIST, TDB_ERR_EINVAL, TDB_ERR_RDONLY}; + TDB_ERR_NOEXIST, TDB_ERR_EINVAL, TDB_ERR_RDONLY, + TDB_ERR_NESTING}; /* debugging uses one of the following levels */ enum tdb_debug_level {TDB_DEBUG_FATAL = 0, TDB_DEBUG_ERROR, |