From aa7e4b8e9cafaa5139b5111aa8ca042e6b6f65f4 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Tue, 20 May 2008 21:54:36 +0200 Subject: 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 (This used to be commit 89543005fe2e4934b3c560c937d49304a32a7fc2) --- source4/lib/tdb/common/traverse.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'source4/lib/tdb/common/traverse.c') diff --git a/source4/lib/tdb/common/traverse.c b/source4/lib/tdb/common/traverse.c index 07b0c23858..5a31742e7b 100644 --- a/source4/lib/tdb/common/traverse.c +++ b/source4/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; } -- cgit From 6d4424cd45333c3029b0272528485dd2b3f8e620 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Tue, 20 May 2008 14:18:58 -0700 Subject: Convert in_transaction to a bool. Add the same fix Volker used for tdb_traverse() to tdb_traverse_read(). Jeremy. (This used to be commit e05ec3047c4fe0cc2e09a812830fc835dc35abea) --- source4/lib/tdb/common/traverse.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'source4/lib/tdb/common/traverse.c') diff --git a/source4/lib/tdb/common/traverse.c b/source4/lib/tdb/common/traverse.c index 5a31742e7b..69c81e6e98 100644 --- a/source4/lib/tdb/common/traverse.c +++ b/source4/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; } @@ -232,7 +237,7 @@ 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); + bool in_transaction = (tdb->transaction != NULL); if (tdb->read_only || tdb->traverse_read) { return tdb_traverse_read(tdb, fn, private_data); -- cgit