remove locking around tcpSesAllocCount atomic variable

The global tcpSesAllocCount variable is an atomic already and doesn't
really need the extra locking around it. Remove the locking and just use
the atomic_inc_return and atomic_dec_return functions to make sure we
access it correctly.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index b51d5777cde695f308c85a2387a56b743ef1820c..34a1fc9dabf5cd68cdeffa8e0d787c81196e9b7a 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -351,11 +351,9 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 
        current->flags |= PF_MEMALLOC;
        cFYI(1, ("Demultiplex PID: %d", task_pid_nr(current)));
-       write_lock(&GlobalSMBSeslock);
-       atomic_inc(&tcpSesAllocCount);
-       length = tcpSesAllocCount.counter;
-       write_unlock(&GlobalSMBSeslock);
-       if (length  > 1)
+
+       length = atomic_inc_return(&tcpSesAllocCount);
+       if (length > 1)
                mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
                                GFP_KERNEL);
 
@@ -745,14 +743,11 @@ multi_t2_fnd:
                coming home not much else we can do but free the memory */
        }
 
-       write_lock(&GlobalSMBSeslock);
-       atomic_dec(&tcpSesAllocCount);
-       length = tcpSesAllocCount.counter;
-
        /* last chance to mark ses pointers invalid
        if there are any pointing to this (e.g
        if a crazy root user tried to kill cifsd
        kernel thread explicitly this might happen) */
+       write_lock(&GlobalSMBSeslock);
        list_for_each(tmp, &GlobalSMBSessionList) {
                ses = list_entry(tmp, struct cifsSesInfo,
                                cifsSessionList);
@@ -763,6 +758,8 @@ multi_t2_fnd:
 
        kfree(server->hostname);
        kfree(server);
+
+       length = atomic_dec_return(&tcpSesAllocCount);
        if (length  > 0)
                mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
                                GFP_KERNEL);