[PATCH] cifs: fix credits leak for SMB1 oplock breaks

[Ronnie Sahlberg <lsahlber@redhat.com>]

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/transport.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 5c59c498f56a..3b80884ddf0f 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -971,7 +971,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		   const int flags, const int num_rqst, struct smb_rqst *rqst,
 		   int *resp_buf_type, struct kvec *resp_iov)
 {
-	int i, j, optype, rc = 0;
+	int i, j, optype, opmask, rc = 0;
 	struct mid_q_entry *midQ[MAX_COMPOUND];
 	bool cancelled_mid[MAX_COMPOUND] = {false};
 	struct cifs_credits credits[MAX_COMPOUND] = {
@@ -981,6 +981,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	char *buf;
 
 	optype = flags & CIFS_OP_MASK;
+	opmask = flags & (CIFS_ASYNC_OP|CIFS_NO_RESP);
 
 	for (i = 0; i < num_rqst; i++)
 		resp_buf_type[i] = CIFS_NO_BUFFER;  /* no response buf yet */
@@ -1073,8 +1074,13 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	mutex_unlock(&ses->server->srv_mutex);
 
-	if (rc < 0) {
-		/* Sending failed for some reason - return credits back */
+	/*
+	 * If sending failed for some reason or it is an oplock break that we
+	 * will not receive a response to - return credits back
+	 */
+	if (rc < 0 ||
+	    (optype == CIFS_OBREAK_OP &&
+	     opmask == (CIFS_ASYNC_OP|CIFS_NO_RESP))) {
 		for (i = 0; i < num_rqst; i++)
 			add_credits(ses->server, &credits[i], optype);
 		goto out;
-- 
2.13.6