1 files changed, 74 insertions, 33 deletions

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 78f96fa3d7d9..83ff0c25710d 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -113,9 +113,18 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
 		cifs_small_buf_release(midEntry->resp_buf);
 #ifdef CONFIG_CIFS_STATS2
 	now = jiffies;
-	/* commands taking longer than one second are indications that
-	   something is wrong, unless it is quite a slow link or server */
-	if (time_after(now, midEntry->when_alloc + HZ) &&
+	/*
+	 * commands taking longer than one second (default) can be indications
+	 * that something is wrong, unless it is quite a slow link or a very
+	 * busy server. Note that this calc is unlikely or impossible to wrap
+	 * as long as slow_rsp_threshold is not set way above recommended max
+	 * value (32767 ie 9 hours) and is generally harmless even if wrong
+	 * since only affects debug counters - so leaving the calc as simple
+	 * comparison rather than doing multiple conversions and overflow
+	 * checks
+	 */
+	if ((slow_rsp_threshold != 0) &&
+	    time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
 	    (midEntry->command != command)) {
 		/* smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command */
 		if ((le16_to_cpu(midEntry->command) < NUMBER_OF_SMB2_COMMANDS) &&
@@ -128,7 +137,7 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
 		if (cifsFYI & CIFS_TIMER) {
 			pr_debug(" CIFS slow rsp: cmd %d mid %llu",
 			       midEntry->command, midEntry->mid);
-			pr_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
+			cifs_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
 			       now - midEntry->when_alloc,
 			       now - midEntry->when_sent,
 			       now - midEntry->when_received);
@@ -142,7 +151,8 @@ void
 cifs_delete_mid(struct mid_q_entry *mid)
 {
 	spin_lock(&GlobalMid_Lock);
-	list_del(&mid->qhead);
+	list_del_init(&mid->qhead);
+	mid->mid_flags |= MID_DELETED;
 	spin_unlock(&GlobalMid_Lock);
 
 	DeleteMidQEntry(mid);
@@ -306,8 +316,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 			.iov_base = &rfc1002_marker,
 			.iov_len  = 4
 		};
-		iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, &hiov,
-			      1, 4);
+		iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
 		rc = smb_send_kvec(server, &smb_msg, &sent);
 		if (rc < 0)
 			goto uncork;
@@ -328,8 +337,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 			size += iov[i].iov_len;
 		}
 
-		iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC,
-			      iov, n_vec, size);
+		iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
 
 		rc = smb_send_kvec(server, &smb_msg, &sent);
 		if (rc < 0)
@@ -345,7 +353,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 			rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
 					     &bvec.bv_offset);
 
-			iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC,
+			iov_iter_bvec(&smb_msg.msg_iter, WRITE,
 				      &bvec, 1, bvec.bv_len);
 			rc = smb_send_kvec(server, &smb_msg, &sent);
 			if (rc < 0)
@@ -772,6 +780,11 @@ cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 	return mid;
 }
 
+static void
+cifs_noop_callback(struct mid_q_entry *mid)
+{
+}
+
 int
 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		   const int flags, const int num_rqst, struct smb_rqst *rqst,
@@ -780,7 +793,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	int i, j, rc = 0;
 	int timeout, optype;
 	struct mid_q_entry *midQ[MAX_COMPOUND];
-	unsigned int credits = 1;
+	unsigned int credits = 0;
 	char *buf;
 
 	timeout = flags & CIFS_TIMEOUT_MASK;
@@ -826,8 +839,13 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		}
 
 		midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
+		/*
+		 * We don't invoke the callback compounds unless it is the last
+		 * request.
+		 */
+		if (i < num_rqst - 1)
+			midQ[i]->callback = cifs_noop_callback;
 	}
-
 	cifs_in_send_inc(ses->server);
 	rc = smb_send_rqst(ses->server, num_rqst, rqst, flags);
 	cifs_in_send_dec(ses->server);
@@ -840,21 +858,24 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	mutex_unlock(&ses->server->srv_mutex);
 
-	for (i = 0; i < num_rqst; i++) {
-		if (rc < 0)
-			goto out;
+	if (rc < 0)
+		goto out;
 
-		if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
-			smb311_update_preauth_hash(ses, rqst[i].rq_iov,
-						   rqst[i].rq_nvec);
+	/*
+	 * Compounding is never used during session establish.
+	 */
+	if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
+		smb311_update_preauth_hash(ses, rqst[0].rq_iov,
+					   rqst[0].rq_nvec);
 
-		if (timeout == CIFS_ASYNC_OP)
-			goto out;
+	if (timeout == CIFS_ASYNC_OP)
+		goto out;
 
+	for (i = 0; i < num_rqst; i++) {
 		rc = wait_for_response(ses->server, midQ[i]);
 		if (rc != 0) {
-			cifs_dbg(FYI, "Cancelling wait for mid %llu\n",
-				 midQ[i]->mid);
+			cifs_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n",
+				 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
 			send_cancel(ses->server, &rqst[i], midQ[i]);
 			spin_lock(&GlobalMid_Lock);
 			if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
@@ -866,10 +887,21 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 			}
 			spin_unlock(&GlobalMid_Lock);
 		}
+	}
+
+	for (i = 0; i < num_rqst; i++)
+		if (midQ[i]->resp_buf)
+			credits += ses->server->ops->get_credits(midQ[i]);
+	if (!credits)
+		credits = 1;
+
+	for (i = 0; i < num_rqst; i++) {
+		if (rc < 0)
+			goto out;
 
 		rc = cifs_sync_mid_result(midQ[i], ses->server);
 		if (rc != 0) {
-			add_credits(ses->server, 1, optype);
+			add_credits(ses->server, credits, optype);
 			return rc;
 		}
 
@@ -890,24 +922,33 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		else
 			resp_buf_type[i] = CIFS_SMALL_BUFFER;
 
-		if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
-			struct kvec iov = {
-				.iov_base = resp_iov[i].iov_base,
-				.iov_len = resp_iov[i].iov_len
-			};
-			smb311_update_preauth_hash(ses, &iov, 1);
-		}
-
-		credits = ses->server->ops->get_credits(midQ[i]);
-
 		rc = ses->server->ops->check_receive(midQ[i], ses->server,
 						     flags & CIFS_LOG_ERROR);
 
 		/* mark it so buf will not be freed by cifs_delete_mid */
 		if ((flags & CIFS_NO_RESP) == 0)
 			midQ[i]->resp_buf = NULL;
+
+	}
+
+	/*
+	 * Compounding is never used during session establish.
+	 */
+	if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
+		struct kvec iov = {
+			.iov_base = resp_iov[0].iov_base,
+			.iov_len = resp_iov[0].iov_len
+		};
+		smb311_update_preauth_hash(ses, &iov, 1);
 	}
+
 out:
+	/*
+	 * This will dequeue all mids. After this it is important that the
+	 * demultiplex_thread will not process any of these mids any futher.
+	 * This is prevented above by using a noop callback that will not
+	 * wake this thread except for the very last PDU.
+	 */
 	for (i = 0; i < num_rqst; i++)
 		cifs_delete_mid(midQ[i]);
 	add_credits(ses->server, credits, optype);