[SCM] Samba Shared Repository - branch v3-3-test updated - release-3-2-0pre2-2534-g80e700e

[Volker Lendecke]

The branch, v3-3-test has been updated
       via  80e700e3bd73f2ffa38046bdcba7f532e25198ef (commit)
      from  830337f054a6c0646d85df33d9958e99283e727a (commit)

http://gitweb.samba.org/?p=samba.git;a=shortlog;h=v3-3-test


- Log -----------------------------------------------------------------
commit 80e700e3bd73f2ffa38046bdcba7f532e25198ef
Author: Volker Lendecke <vl at samba.org>
Date:   Tue May 20 21:54:36 2008 +0200

    Fix nesting tdb_traverse in a transaction
    
    Calling tdb_traverse inside a transaction led to the transaction lock being
    held indefinitely. This was caused by the tdb_transaction_lock/unlock inside
    tdb_traverse: The transaction code holds the global lock at offset
    TRANSACTION_LOCK. The call to tdb_transaction_lock does nothing because the
    transaction_lock is already being held. tdb_transaction_unlock inside tdb_wrap
    resets tdb->have_transaction_lock but does not release the kernel-level fcntl
    lock. transaction_commit later on does not release that fcntl lock either,
    because tdb->have_transaction_lock was already reset by tdb_transaction().
    
    This patch does fix that problem for me. An alternative would be to make
    tdb->have_transaction_lock a counter that can cope with proper nesting, maybe
    in other places as well.
    
    Volker

-----------------------------------------------------------------------

Summary of changes:
 source/lib/tdb/common/traverse.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)


Changeset truncated at 500 lines:

diff --git a/source/lib/tdb/common/traverse.c b/source/lib/tdb/common/traverse.c
index 07b0c23..5a31742 100644
--- a/source/lib/tdb/common/traverse.c
+++ b/source/lib/tdb/common/traverse.c
@@ -232,20 +232,25 @@ int tdb_traverse(struct tdb_context *tdb,
 {
 	struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK };
 	int ret;
+	int in_transaction = (tdb->transaction != NULL);
 
 	if (tdb->read_only || tdb->traverse_read) {
 		return tdb_traverse_read(tdb, fn, private_data);
 	}
 	
-	if (tdb_transaction_lock(tdb, F_WRLCK)) {
-		return -1;
+	if (!in_transaction) {
+		if (tdb_transaction_lock(tdb, F_WRLCK)) {
+			return -1;
+		}
 	}
 
 	tdb->traverse_write++;
 	ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
 	tdb->traverse_write--;
 
-	tdb_transaction_unlock(tdb);
+	if (!in_transaction) {
+		tdb_transaction_unlock(tdb);
+	}
 
 	return ret;
 }


-- 
Samba Shared Repository