dbwrap_watch: Don't alert ourselves, fix raw.oplock.batch26 race
This fixes the following flaky test:
UNEXPECTED(failure): samba3.raw.oplock.batch26(nt4_dc)
REASON: Exception: Exception: (../../source4/torture/raw/oplock.c:3718): wrong value for break_info.count got 0x2 - should be 0x1
You can reproduce it with two small msleeps, which means it's a race
condition:
diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index
20b5a3e294c..
126c7fc021d 100644
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -1917,6 +1917,14 @@ NTSTATUS send_break_message(struct messaging_context *msg_ctx,
DATA_BLOB blob;
NTSTATUS status;
+ {
+ static bool sent = false;
+ if (sent) {
+ smb_msleep(500);
+ }
+ sent = true;
+ }
+
if (DEBUGLVL(10)) {
struct server_id_buf buf;
DBG_DEBUG("Sending break message to %s\n",
diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index
b3da84b1269..
d9c4dbb9487 100644
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -858,6 +858,8 @@ static void process_oplock_break_message(struct messaging_context *msg_ctx,
uint16_t break_to;
bool break_needed = true;
+ smb_msleep(100);
+
msg = talloc(talloc_tos(), struct oplock_break_message);
if (msg == NULL) {
DBG_WARNING("talloc failed\n");
15a8af075a2 introduced a bug where we immediately wake up ourselves
after doing a watch_send, leading to two inter-smbd oplock break
messages for this case. In theory, this should not matter, as in the
oplock break handler in the destination smbd we check
(fsp->sent_oplock_break != NO_BREAK_SENT)
so that the break does not get sent twice. However, with the above two
sleeps the oplock holding client could send out its oplock downgrade
while the second inter-smbd break messages was on its way.
The real fix would be to note in the share mode array that the
inter-smbd message has already been sent, but as other users of
dbwrap_watched_watch_send might also be affected by this bug, this fix
should be sufficient to get rid of this flaky test.
Unfortunately, dbwrap_watch.c is now pretty complex and needs some
serious refactoring to become understandable again. But that's
something for another day, sorry.
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>