CIFS: Prepare credits code for a slot reservation

that is essential for CIFS/SMB/SMB2 oplock breaks and SMB2 echos.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 14 insertions, 8 deletions

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 58b31da17fc5..310918b6fcb4 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -255,26 +255,26 @@ smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
 }
 
 static int
-wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
+wait_for_free_credits(struct TCP_Server_Info *server, const int optype,
+                      int *credits)
 {
         int rc;
 
         spin_lock(&server->req_lock);
-
-        if (long_op == CIFS_ASYNC_OP) {
+        if (optype == CIFS_ASYNC_OP) {
                 /* oplock breaks must not be held up */
                 server->in_flight++;
-                server->credits--;
+                *credits -= 1;
                 spin_unlock(&server->req_lock);
                 return 0;
         }
 
         while (1) {
-                if (server->credits <= 0) {
+                if (*credits <= 0) {
                         spin_unlock(&server->req_lock);
                         cifs_num_waiters_inc(server);
                         rc = wait_event_killable(server->request_q,
-                                                 has_credits(server));
+                                                 has_credits(server, credits));
                         cifs_num_waiters_dec(server);
                         if (rc)
                                 return rc;
@@ -291,8 +291,8 @@ wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
                          */
 
                         /* update # of requests on the wire to server */
-                        if (long_op != CIFS_BLOCKING_OP) {
-                                server->credits--;
+                        if (optype != CIFS_BLOCKING_OP) {
+                                *credits -= 1;
                                 server->in_flight++;
                         }
                         spin_unlock(&server->req_lock);
@@ -302,6 +302,12 @@ wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
         return 0;
 }
 
+static int
+wait_for_free_request(struct TCP_Server_Info *server, const int optype)
+{
+        return wait_for_free_credits(server, optype, get_credits_field(server));
+}
+
 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
                         struct mid_q_entry **ppmidQ)
 {