From 6f9e7505b29da753d98dba4de98e2dbf7e6b6b2b Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Thu, 18 Dec 2008 13:27:42 -0800 Subject: Fix bug #5980 - Race condition when granting level2 oplocks can cause break notify to be missed. Jeremy. --- source3/smbd/oplock.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) (limited to 'source3/smbd') diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c index c98d11426d..261d8fd670 100644 --- a/source3/smbd/oplock.c +++ b/source3/smbd/oplock.c @@ -821,10 +821,33 @@ void release_level_2_oplocks_on_change(files_struct *fsp) share_mode_entry_to_message(msg, share_entry); - messaging_send_buf(smbd_messaging_context(), share_entry->pid, - MSG_SMB_ASYNC_LEVEL2_BREAK, - (uint8 *)msg, - MSG_SMB_SHARE_MODE_ENTRY_SIZE); + /* + * Deal with a race condition when breaking level2 + * oplocks. Don't send all the messages and release + * the lock, this allows someone else to come in and + * get a level2 lock before any of the messages are + * processed, and thus miss getting a break message. + * Ensure at least one entry (the one we're breaking) + * is processed immediately under the lock and becomes + * set as NO_OPLOCK to stop any waiter getting a level2. + * Bugid #5980. + */ + + if (procid_is_me(&share_entry->pid)) { + DATA_BLOB blob = data_blob_const(msg, + MSG_SMB_SHARE_MODE_ENTRY_SIZE); + process_oplock_async_level2_break_message(smbd_messaging_context(), + NULL, + MSG_SMB_ASYNC_LEVEL2_BREAK, + share_entry->pid, + &blob); + } else { + messaging_send_buf(smbd_messaging_context(), + share_entry->pid, + MSG_SMB_ASYNC_LEVEL2_BREAK, + (uint8 *)msg, + MSG_SMB_SHARE_MODE_ENTRY_SIZE); + } } /* We let the message receivers handle removing the oplock state -- cgit