[SCM] Samba Shared Repository - branch v3-2-test updated - release-3-2-0pre2-2388-ga0e1d8a

[Jeremy Allison]

The branch, v3-2-test has been updated
       via  a0e1d8ac4dd9121312fd66ecb2e2942513df5a4b (commit)
       via  fd0b60a9e000f969cf99a8d670080cc7a52d97d8 (commit)
      from  47eb2e8fa858d9f12637eb9a10466271335f61aa (commit)

http://gitweb.samba.org/?p=samba.git;a=shortlog;h=v3-2-test


- Log -----------------------------------------------------------------
commit a0e1d8ac4dd9121312fd66ecb2e2942513df5a4b
Author: Jeremy Allison <jra at samba.org>
Date:   Tue May 20 14:18:58 2008 -0700

    Convert in_transaction to a bool. Add the same fix Volker
    used for tdb_traverse() to tdb_traverse_read().
    Jeremy.

commit fd0b60a9e000f969cf99a8d670080cc7a52d97d8
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 |   22 ++++++++++++++++------
 1 files changed, 16 insertions(+), 6 deletions(-)


Changeset truncated at 500 lines:

diff --git a/source/lib/tdb/common/traverse.c b/source/lib/tdb/common/traverse.c
index 07b0c23..69c81e6 100644
--- a/source/lib/tdb/common/traverse.c
+++ b/source/lib/tdb/common/traverse.c
@@ -204,18 +204,23 @@ int tdb_traverse_read(struct tdb_context *tdb,
 {
 	struct tdb_traverse_lock tl = { NULL, 0, 0, F_RDLCK };
 	int ret;
+	bool in_transaction = (tdb->transaction != NULL);
 
 	/* we need to get a read lock on the transaction lock here to
 	   cope with the lock ordering semantics of solaris10 */
-	if (tdb_transaction_lock(tdb, F_RDLCK)) {
-		return -1;
+	if (!in_transaction) {
+		if (tdb_transaction_lock(tdb, F_RDLCK)) {
+			return -1;
+		}
 	}
 
 	tdb->traverse_read++;
 	ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
 	tdb->traverse_read--;
 
-	tdb_transaction_unlock(tdb);
+	if (!in_transaction) {
+		tdb_transaction_unlock(tdb);
+	}
 
 	return ret;
 }
@@ -232,20 +237,25 @@ int tdb_traverse(struct tdb_context *tdb,
 {
 	struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK };
 	int ret;
+	bool 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