5 files changed, 52 insertions, 33 deletions

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 24b3dfc05282..573b899b5a5d 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -171,8 +171,7 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
                         seq_printf(m, "TCP status: %d\n\tLocal Users To "
                                    "Server: %d SecMode: 0x%x Req On Wire: %d",
                                    server->tcpStatus, server->srv_count,
-                                   server->sec_mode,
-                                   atomic_read(&server->inFlight));
+                                   server->sec_mode, in_flight(server));
 
 #ifdef CONFIG_CIFS_STATS2
                         seq_printf(m, " In Send: %d In MaxReq Wait: %d",
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index d47d20aac670..fb78bc903887 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -250,7 +250,8 @@ struct TCP_Server_Info {
         bool noblocksnd;                /* use blocking sendmsg */
         bool noautotune;                /* do not autotune send buf sizes */
         bool tcp_nodelay;
-        atomic_t inFlight;  /* number of requests on the wire to server */
+        unsigned int in_flight;  /* number of requests on the wire to server */
+        spinlock_t req_lock; /* protect the value above */
         struct mutex srv_mutex;
         struct task_struct *tsk;
         char server_GUID[16];
@@ -303,6 +304,24 @@ struct TCP_Server_Info {
 #endif
 };
 
+static inline unsigned int
+in_flight(struct TCP_Server_Info *server)
+{
+        unsigned int num;
+        spin_lock(&server->req_lock);
+        num = server->in_flight;
+        spin_unlock(&server->req_lock);
+        return num;
+}
+
+static inline void
+dec_in_flight(struct TCP_Server_Info *server)
+{
+        spin_lock(&server->req_lock);
+        server->in_flight--;
+        spin_unlock(&server->req_lock);
+}
+
 /*
  * Macros to allow the TCP_Server_Info->net field and related code to drop out
  * when CONFIG_NET_NS isn't set.
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index cd66b76e3282..d7cbcfa21a0c 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -721,7 +721,7 @@ cifs_echo_callback(struct mid_q_entry *mid)
         struct TCP_Server_Info *server = mid->callback_data;
 
         DeleteMidQEntry(mid);
-        atomic_dec(&server->inFlight);
+        dec_in_flight(server);
         wake_up(&server->request_q);
 }
 
@@ -1674,7 +1674,7 @@ cifs_readv_callback(struct mid_q_entry *mid)
 
         queue_work(system_nrt_wq, &rdata->work);
         DeleteMidQEntry(mid);
-        atomic_dec(&server->inFlight);
+        dec_in_flight(server);
         wake_up(&server->request_q);
 }
 
@@ -2115,7 +2115,7 @@ cifs_writev_callback(struct mid_q_entry *mid)
 
         queue_work(system_nrt_wq, &wdata->work);
         DeleteMidQEntry(mid);
-        atomic_dec(&tcon->ses->server->inFlight);
+        dec_in_flight(tcon->ses->server);
         wake_up(&tcon->ses->server->request_q);
 }
 
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 0ac595c8c262..ed91abcce8a9 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -643,14 +643,14 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
         wake_up_all(&server->response_q);
 
         /* Check if we have blocked requests that need to free. */
-        spin_lock(&GlobalMid_Lock);
-        if (atomic_read(&server->inFlight) >= server->maxReq)
-                atomic_set(&server->inFlight, server->maxReq - 1);
+        spin_lock(&server->req_lock);
+        if (server->in_flight >= server->maxReq)
+                server->in_flight = server->maxReq - 1;
         /*
          * We do not want to set the max_pending too low or we could end up
          * with the counter going negative.
          */
-        spin_unlock(&GlobalMid_Lock);
+        spin_unlock(&server->req_lock);
         /*
          * Although there should not be any requests blocked on this queue it
          * can not hurt to be paranoid and try to wake up requests that may
@@ -1905,7 +1905,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
         tcp_ses->noblocksnd = volume_info->noblocksnd;
         tcp_ses->noautotune = volume_info->noautotune;
         tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay;
-        atomic_set(&tcp_ses->inFlight, 0);
+        tcp_ses->in_flight = 0;
         tcp_ses->maxReq = 1; /* enough to send negotiate request */
         init_waitqueue_head(&tcp_ses->response_q);
         init_waitqueue_head(&tcp_ses->request_q);
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 99a27cfa6cd2..e2673aa34381 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -254,28 +254,29 @@ smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
         return smb_sendv(server, &iov, 1);
 }
 
-static int wait_for_free_request(struct TCP_Server_Info *server,
-                                 const int long_op)
+static int
+wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
 {
+        spin_lock(&server->req_lock);
+
         if (long_op == CIFS_ASYNC_OP) {
                 /* oplock breaks must not be held up */
-                atomic_inc(&server->inFlight);
+                server->in_flight++;
+                spin_unlock(&server->req_lock);
                 return 0;
         }
 
-        spin_lock(&GlobalMid_Lock);
         while (1) {
-                if (atomic_read(&server->inFlight) >= server->maxReq) {
-                        spin_unlock(&GlobalMid_Lock);
+                if (server->in_flight >= server->maxReq) {
+                        spin_unlock(&server->req_lock);
                         cifs_num_waiters_inc(server);
                         wait_event(server->request_q,
-                                   atomic_read(&server->inFlight)
-                                     < server->maxReq);
+                                   in_flight(server) < server->maxReq);
                         cifs_num_waiters_dec(server);
-                        spin_lock(&GlobalMid_Lock);
+                        spin_lock(&server->req_lock);
                 } else {
                         if (server->tcpStatus == CifsExiting) {
-                                spin_unlock(&GlobalMid_Lock);
+                                spin_unlock(&server->req_lock);
                                 return -ENOENT;
                         }
 
@@ -284,8 +285,8 @@ static int wait_for_free_request(struct TCP_Server_Info *server,
 
                         /* update # of requests on the wire to server */
                         if (long_op != CIFS_BLOCKING_OP)
-                                atomic_inc(&server->inFlight);
-                        spin_unlock(&GlobalMid_Lock);
+                                server->in_flight++;
+                        spin_unlock(&server->req_lock);
                         break;
                 }
         }
@@ -359,7 +360,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
         mid = AllocMidQEntry(hdr, server);
         if (mid == NULL) {
                 mutex_unlock(&server->srv_mutex);
-                atomic_dec(&server->inFlight);
+                dec_in_flight(server);
                 wake_up(&server->request_q);
                 return -ENOMEM;
         }
@@ -392,7 +393,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
         return rc;
 out_err:
         delete_mid(mid);
-        atomic_dec(&server->inFlight);
+        dec_in_flight(server);
         wake_up(&server->request_q);
         return rc;
 }
@@ -564,7 +565,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
                 mutex_unlock(&ses->server->srv_mutex);
                 cifs_small_buf_release(in_buf);
                 /* Update # of requests on wire to server */
-                atomic_dec(&ses->server->inFlight);
+                dec_in_flight(ses->server);
                 wake_up(&ses->server->request_q);
                 return rc;
         }
@@ -601,7 +602,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
                         midQ->callback = DeleteMidQEntry;
                         spin_unlock(&GlobalMid_Lock);
                         cifs_small_buf_release(in_buf);
-                        atomic_dec(&ses->server->inFlight);
+                        dec_in_flight(ses->server);
                         wake_up(&ses->server->request_q);
                         return rc;
                 }
@@ -612,7 +613,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 
         rc = cifs_sync_mid_result(midQ, ses->server);
         if (rc != 0) {
-                atomic_dec(&ses->server->inFlight);
+                dec_in_flight(ses->server);
                 wake_up(&ses->server->request_q);
                 return rc;
         }
@@ -637,7 +638,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
                 midQ->resp_buf = NULL;
 out:
         delete_mid(midQ);
-        atomic_dec(&ses->server->inFlight);
+        dec_in_flight(ses->server);
         wake_up(&ses->server->request_q);
 
         return rc;
@@ -688,7 +689,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
         if (rc) {
                 mutex_unlock(&ses->server->srv_mutex);
                 /* Update # of requests on wire to server */
-                atomic_dec(&ses->server->inFlight);
+                dec_in_flight(ses->server);
                 wake_up(&ses->server->request_q);
                 return rc;
         }
@@ -721,7 +722,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
                         /* no longer considered to be "in-flight" */
                         midQ->callback = DeleteMidQEntry;
                         spin_unlock(&GlobalMid_Lock);
-                        atomic_dec(&ses->server->inFlight);
+                        dec_in_flight(ses->server);
                         wake_up(&ses->server->request_q);
                         return rc;
                 }
@@ -730,7 +731,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 
         rc = cifs_sync_mid_result(midQ, ses->server);
         if (rc != 0) {
-                atomic_dec(&ses->server->inFlight);
+                dec_in_flight(ses->server);
                 wake_up(&ses->server->request_q);
                 return rc;
         }
@@ -747,7 +748,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
         rc = cifs_check_receive(midQ, ses->server, 0);
 out:
         delete_mid(midQ);
-        atomic_dec(&ses->server->inFlight);
+        dec_in_flight(ses->server);
         wake_up(&ses->server->request_q);
 
         return rc;