Plumb the SMB2 front end into the blocking lock backend.

Metze, you'll probably be happier with this work as it
doesn't abuse tevent in the way you dislike. This is a
first cut at the code, which will need lots of testing
but I'm hoping this will give people an idea of where I'm
going with this.

Jeremy.

1 files changed, 454 insertions, 18 deletions

diff --git a/source3/smbd/smb2_lock.c b/source3/smbd/smb2_lock.c
index d7a6cb1376..ba5b03f573 100644
--- a/source3/smbd/smb2_lock.c
+++ b/source3/smbd/smb2_lock.c
@@ -135,6 +135,22 @@ static void smbd_smb2_request_lock_done(struct tevent_req *subreq)
 	NTSTATUS status;
 	NTSTATUS error; /* transport error */
 
+	if (req->cancelled) {
+		const uint8_t *inhdr = (const uint8_t *)
+			req->in.vector[req->current_idx].iov_base;
+		uint64_t mid = BVAL(inhdr, SMB2_HDR_MESSAGE_ID);
+
+		DEBUG(10,("smbd_smb2_request_lock_done: cancelled mid %llu\n",
+			(unsigned long long)mid ));
+		error = smbd_smb2_request_error(req, NT_STATUS_CANCELLED);
+		if (!NT_STATUS_IS_OK(error)) {
+			smbd_server_connection_terminate(req->sconn,
+				nt_errstr(error));
+			return;
+		}
+		return;
+	}
+
 	status = smbd_smb2_lock_recv(subreq);
 	TALLOC_FREE(subreq);
 	if (!NT_STATUS_IS_OK(status)) {
@@ -171,6 +187,10 @@ static void smbd_smb2_request_lock_done(struct tevent_req *subreq)
 
 struct smbd_smb2_lock_state {
 	struct smbd_smb2_request *smb2req;
+	struct smb_request *smb1req;
+	struct blocking_lock_record *blr;
+	uint16_t lock_count;
+	struct smbd_lock_element *locks;
 };
 
 static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
@@ -183,7 +203,7 @@ static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
 {
 	struct tevent_req *req;
 	struct smbd_smb2_lock_state *state;
-	struct smb_request *smbreq;
+	struct smb_request *smb1req;
 	connection_struct *conn = smb2req->tcon->compat_conn;
 	files_struct *fsp;
 	int32_t timeout = -1;
@@ -194,21 +214,21 @@ static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
 	bool async = false;
 
 	req = tevent_req_create(mem_ctx, &state,
-				struct smbd_smb2_lock_state);
+			struct smbd_smb2_lock_state);
 	if (req == NULL) {
 		return NULL;
 	}
 	state->smb2req = smb2req;
+	smb1req = smbd_smb2_fake_smb_request(smb2req);
+	if (tevent_req_nomem(smb1req, req)) {
+		return tevent_req_post(req, ev);
+	}
+	state->smb1req = smb1req;
 
 	DEBUG(10,("smbd_smb2_lock_send: file_id[0x%016llX]\n",
 		  (unsigned long long)in_file_id_volatile));
 
-	smbreq = smbd_smb2_fake_smb_request(smb2req);
-	if (tevent_req_nomem(smbreq, req)) {
-		return tevent_req_post(req, ev);
-	}
-
-	fsp = file_fsp(smbreq, (uint16_t)in_file_id_volatile);
+	fsp = file_fsp(smb1req, (uint16_t)in_file_id_volatile);
 	if (fsp == NULL) {
 		tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 		return tevent_req_post(req, ev);
@@ -333,8 +353,11 @@ static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
 		}
 	}
 
+	state->locks = locks;
+	state->lock_count = in_lock_count;
+
 	if (isunlock) {
-		status = smbd_do_locking(smbreq, fsp,
+		status = smbd_do_locking(smb1req, fsp,
 					 0,
 					 timeout,
 					 in_lock_count,
@@ -343,7 +366,7 @@ static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
 					 NULL,
 					 &async);
 	} else {
-		status = smbd_do_locking(smbreq, fsp,
+		status = smbd_do_locking(smb1req, fsp,
 					 0,
 					 timeout,
 					 0,
@@ -361,8 +384,7 @@ static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
 	}
 
 	if (async) {
-		tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
-		return tevent_req_post(req, ev);
+		return req;
 	}
 
 	tevent_req_done(req);
@@ -382,13 +404,163 @@ static NTSTATUS smbd_smb2_lock_recv(struct tevent_req *req)
 	return NT_STATUS_OK;
 }
 
-/*
- * Dummy (for now) function to cope with SMB2 blocking lock
- * requests.
- */
+/****************************************************************
+ Cancel an outstanding blocking lock request.
+*****************************************************************/
+
+static bool smbd_smb2_lock_cancel(struct tevent_req *req)
+{
+        struct smbd_smb2_request *smb2req = NULL;
+        struct smbd_smb2_lock_state *state = tevent_req_data(req,
+                                struct smbd_smb2_lock_state);
+        if (!state) {
+                return false;
+        }
+
+        if (!state->smb2req) {
+                return false;
+        }
+
+        smb2req = state->smb2req;
+        smb2req->cancelled = true;
+
+        tevent_req_done(req);
+        return true;
+}
+
+/****************************************************************
+ Got a message saying someone unlocked a file. Re-schedule all
+ blocking lock requests as we don't know if anything overlapped.
+*****************************************************************/
+
+static void received_unlock_msg(struct messaging_context *msg,
+				void *private_data,
+				uint32_t msg_type,
+				struct server_id server_id,
+				DATA_BLOB *data)
+{
+	DEBUG(10,("received_unlock_msg (SMB2)\n"));
+	process_blocking_lock_queue_smb2();
+}
+
+/****************************************************************
+ Function to get the blr on a pending record.
+*****************************************************************/
+
+struct blocking_lock_record *get_pending_smb2req_blr(struct smbd_smb2_request *smb2req)
+{
+	struct smbd_smb2_lock_state *state = NULL;
+	const uint8_t *inhdr;
+
+	if (!smb2req) {
+		return NULL;
+	}
+	if (smb2req->subreq == NULL) {
+		return NULL;
+	}
+	if (!tevent_req_is_in_progress(smb2req->subreq)) {
+		return NULL;
+	}
+	inhdr = (const uint8_t *)smb2req->in.vector[smb2req->current_idx].iov_base;
+	if (IVAL(inhdr, SMB2_HDR_OPCODE) != SMB2_OP_LOCK) {
+		return NULL;
+	}
+	state = tevent_req_data(smb2req->subreq,
+			struct smbd_smb2_lock_state);
+	if (!state) {
+		return NULL;
+	}
+	return state->blr;
+}
+/****************************************************************
+ Set up the next brl timeout.
+*****************************************************************/
+
+static bool recalc_smb2_brl_timeout(struct smbd_server_connection *sconn)
+{
+	struct smbd_smb2_request *smb2req;
+	struct timeval next_timeout = timeval_zero();
+	int max_brl_timeout = lp_parm_int(-1, "brl", "recalctime", 5);
+
+	/*
+	 * If we already have a timeout event, don't replace it.
+	 * It will fire before this one anyway.
+	 */
+
+	if (sconn->smb2.locks.brl_timeout) {
+		DEBUG(10,("recalc_smb2_brl_timeout: timeout already exists\n"));
+		return true;
+	}
+
+	for (smb2req = sconn->smb2.requests; smb2req; smb2req = smb2req->next) {
+		struct blocking_lock_record *blr =
+			get_pending_smb2req_blr(smb2req);
+		if (blr && blr->blocking_pid == 0xFFFFFFFF) {
+			/*
+			 * If we're blocked on pid 0xFFFFFFFF this is
+			 * a POSIX lock, so calculate a timeout of
+			 * 10 seconds into the future.
+			 */
+			next_timeout = timeval_current_ofs(10, 0);
+			break;
+		}
+	}
+
+        /*
+	 * To account for unclean shutdowns by clients we need a
+	 * maximum timeout that we use for checking pending locks. If
+	 * we have any pending locks at all, then check if the pending
+	 * lock can continue at least every brl:recalctime seconds
+	 * (default 5 seconds).
+	 *
+	 * This saves us needing to do a message_send_all() in the
+	 * SIGCHLD handler in the parent daemon. That
+	 * message_send_all() caused O(n^2) work to be done when IP
+	 * failovers happened in clustered Samba, which could make the
+	 * entire system unusable for many minutes.
+	 */
+
+	if (max_brl_timeout > 0) {
+		struct timeval min_to = timeval_current_ofs(max_brl_timeout, 0);
+		next_timeout = timeval_brl_min(&next_timeout, &min_to);
+	}
+
+	if (timeval_is_zero(&next_timeout)) {
+		/* Infinite timeout - return. */
+		DEBUG(10, ("push_blocking_lock_request_smb2: Next "
+			"timeout = INFINITY\n"));
+		return true;
+	}
+
+	if (DEBUGLVL(10)) {
+		struct timeval cur, from_now;
+
+		cur = timeval_current();
+		from_now = timeval_until(&cur, &next_timeout);
+		DEBUG(10, ("push_blocking_lock_request_smb2: Next "
+			"timeout = %d.%d seconds from now.\n",
+			(int)from_now.tv_sec, (int)from_now.tv_usec));
+	}
+
+	sconn->smb2.locks.brl_timeout = event_add_timed(
+				smbd_event_context(),
+				NULL,
+				next_timeout,
+				brl_timeout_fn,
+				NULL);
+	if (!sconn->smb2.locks.brl_timeout) {
+		return false;
+	}
+	return true;
+}
+
+/****************************************************************
+ Get an SMB2 lock reqeust to go async. lock_timeout should
+ always be -1 here.
+*****************************************************************/
 
 bool push_blocking_lock_request_smb2( struct byte_range_lock *br_lck,
-				struct smb_request *req,
+				struct smb_request *smb1req,
 				files_struct *fsp,
 				int lock_timeout,
 				int lock_num,
@@ -399,10 +571,274 @@ bool push_blocking_lock_request_smb2( struct byte_range_lock *br_lck,
 				uint64_t count,
 				uint32_t blocking_pid)
 {
-	return false;
+	struct smbd_server_connection *sconn = smbd_server_conn;
+	struct smbd_smb2_request *smb2req = smb1req->smb2req;
+	struct tevent_req *req = NULL;
+	struct smbd_smb2_lock_state *state = NULL;
+	NTSTATUS status = NT_STATUS_OK;
+
+	SMB_ASSERT(lock_timeout == -1);
+
+	if (!smb2req) {
+		return false;
+	}
+	req = smb2req->subreq;
+	if (!req) {
+		return false;
+	}
+	state = tevent_req_data(req, struct smbd_smb2_lock_state);
+	if (!state) {
+		return false;
+	}
+
+	if (!state->blr) {
+		struct blocking_lock_record *blr = talloc_zero(state,
+					struct blocking_lock_record);
+		if (!blr) {
+			return false;
+		}
+		blr = talloc_zero(state, struct blocking_lock_record);
+		blr->fsp = fsp;
+		blr->expire_time.tv_sec = 0;
+		blr->expire_time.tv_usec = 0; /* Never expire. */
+		blr->lock_num = lock_num;
+		blr->lock_pid = lock_pid;
+		blr->blocking_pid = blocking_pid;
+		blr->lock_flav = lock_flav;
+		blr->lock_type = lock_type;
+		blr->offset = offset;
+		blr->count = count;
+
+		/* Specific brl_lock() implementations can fill this in. */
+		blr->blr_private = NULL;
+
+		/* Add a pending lock record for this. */
+		status = brl_lock(smbd_messaging_context(),
+			br_lck,
+			lock_pid,
+			procid_self(),
+			offset,
+			count,
+			lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
+			blr->lock_flav,
+			true,
+			NULL,
+			blr);
+
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(0,("push_blocking_lock_request_smb2: "
+				"failed to add PENDING_LOCK record.\n"));
+			TALLOC_FREE(blr);
+			return false;
+		}
+		state->blr = blr;
+	}
+
+	recalc_smb2_brl_timeout(sconn);
+
+	/* Ensure we'll receive messages when this is unlocked. */
+	if (!sconn->smb2.locks.blocking_lock_unlock_state) {
+		messaging_register(smbd_messaging_context(), NULL,
+				MSG_SMB_UNLOCK, received_unlock_msg);
+		sconn->smb2.locks.blocking_lock_unlock_state = true;
+        }
+
+	/* allow this request to be canceled */
+	tevent_req_set_cancel_fn(req, smbd_smb2_lock_cancel);
+
+	return true;
+}
+
+/****************************************************************
+ Re-proccess a blocking lock request.
+ This is equivalent to process_lockingX() inside smbd/blocking.c
+*****************************************************************/
+
+static void reprocess_blocked_smb2_lock(struct smbd_smb2_request *smb2req)
+{
+	NTSTATUS status;
+	struct blocking_lock_record *blr = NULL;
+	struct smbd_smb2_lock_state *state = NULL;
+	files_struct *fsp = NULL;
+
+	if (!smb2req->subreq) {
+		return;
+	}
+	state = tevent_req_data(smb2req->subreq, struct smbd_smb2_lock_state);
+	if (!state) {
+		return;
+	}
+
+	blr = state->blr;
+	fsp = blr->fsp;
+
+	/* Try and finish off getting all the outstanding locks. */
+
+	for (; blr->lock_num < state->lock_count; blr->lock_num++) {
+		struct byte_range_lock *br_lck = NULL;
+		struct smbd_lock_element *e = &state->locks[blr->lock_num];
+
+		br_lck = do_lock(smbd_messaging_context(),
+				fsp,
+				e->smbpid,
+				e->count,
+				e->offset,
+				e->brltype,
+				WINDOWS_LOCK,
+				true,
+				&status,
+				&blr->blocking_pid,
+				blr);
+
+		TALLOC_FREE(br_lck);
+
+		if (NT_STATUS_IS_ERR(status)) {
+			break;
+		}
+	}
+
+	if(blr->lock_num == state->lock_count) {
+		/*
+		 * Success - we got all the locks.
+		 */
+
+		DEBUG(3,("reprocess_blocked_smb2_lock SUCCESS file = %s, "
+			"fnum=%d num_locks=%d\n",
+			fsp_str_dbg(fsp),
+			fsp->fnum,
+			(int)state->lock_count));
+
+		tevent_req_done(smb2req->subreq);
+		return;
+	}
+
+	if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
+			!NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
+		/*
+		 * We have other than a "can't get lock"
+		 * error. Return an error.
+		 */
+		tevent_req_nterror(smb2req->subreq, status);
+		return;
+        }
+
+	/*
+	 * Still can't get all the locks - keep waiting.
+	 */
+
+	DEBUG(10,("reprocess_blocked_smb2_lock: only got %d locks of %d needed "
+		"for file %s, fnum = %d. Waiting....\n",
+		(int)blr->lock_num,
+		(int)state->lock_count,
+		fsp_str_dbg(fsp),
+		(int)fsp->fnum));
+
+        return;
+
+}
+
+/****************************************************************
+ Attempt to proccess all outstanding blocking locks pending on
+ the request queue.
+*****************************************************************/
+
+void process_blocking_lock_queue_smb2(void)
+{
+	struct smbd_server_connection *sconn = smbd_server_conn;
+	struct smbd_smb2_request *smb2req, *nextreq;
+
+	for (smb2req = sconn->smb2.requests; smb2req; smb2req = nextreq) {
+		const uint8_t *inhdr;
+
+		nextreq = smb2req->next;
+
+		if (smb2req->subreq == NULL) {
+			/* This message has been processed. */
+			continue;
+		}
+		if (!tevent_req_is_in_progress(smb2req->subreq)) {
+			/* This message has been processed. */
+			continue;
+		}
+
+		inhdr = (const uint8_t *)smb2req->in.vector[smb2req->current_idx].iov_base;
+		if (IVAL(inhdr, SMB2_HDR_OPCODE) == SMB2_OP_LOCK) {
+			reprocess_blocked_smb2_lock(smb2req);
+		}
+	}
+
+	recalc_smb2_brl_timeout(sconn);
 }
 
+/****************************************************************************
+ Remove any locks on this fd. Called from file_close().
+****************************************************************************/
+
 void cancel_pending_lock_requests_by_fid_smb2(files_struct *fsp,
 			struct byte_range_lock *br_lck)
 {
+	struct smbd_server_connection *sconn = smbd_server_conn;
+	struct smbd_smb2_request *smb2req, *nextreq;
+
+	for (smb2req = sconn->smb2.requests; smb2req; smb2req = nextreq) {
+		struct smbd_smb2_lock_state *state = NULL;
+		files_struct *fsp_curr = NULL;
+		int i = smb2req->current_idx;
+		uint64_t in_file_id_volatile;
+		struct blocking_lock_record *blr = NULL;
+		const uint8_t *inhdr;
+		const uint8_t *inbody;
+
+		nextreq = smb2req->next;
+
+		if (smb2req->subreq == NULL) {
+			/* This message has been processed. */
+			continue;
+		}
+		if (!tevent_req_is_in_progress(smb2req->subreq)) {
+			/* This message has been processed. */
+			continue;
+		}
+
+		inhdr = (const uint8_t *)smb2req->in.vector[i].iov_base;
+		if (IVAL(inhdr, SMB2_HDR_OPCODE) != SMB2_OP_LOCK) {
+			/* Not a lock call. */
+			continue;
+		}
+
+		inbody = (const uint8_t *)smb2req->in.vector[i+1].iov_base;
+		in_file_id_volatile = BVAL(inbody, 0x10);
+
+		state = tevent_req_data(smb2req->subreq,
+				struct smbd_smb2_lock_state);
+		if (!state) {
+			/* Strange - is this even possible ? */
+			continue;
+		}
+
+		fsp_curr = file_fsp(state->smb1req, (uint16_t)in_file_id_volatile);
+		if (fsp_curr == NULL) {
+			/* Strange - is this even possible ? */
+			continue;
+		}
+
+		if (fsp_curr != fsp) {
+			/* It's not our fid */
+			continue;
+		}
+
+		blr = state->blr;
+
+		/* Remove the entries from the lock db. */
+		brl_lock_cancel(br_lck,
+				blr->lock_pid,
+				procid_self(),
+				blr->offset,
+				blr->count,
+				blr->lock_flav,
+				blr);
+
+		/* Finally cancel the request. */
+		tevent_req_cancel(smb2req->subreq);
+	}
 }