cifs: clean up accesses to midCount

It's an atomic_t and the code accesses the "counter" field in it directly
instead of using atomic_read(). It also is sometimes accessed under a
spinlock and sometimes not. Move it out of the spinlock since we don't need
belt-and-suspenders for something that's just informational.

Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifs_debug.c

@@ -331,7 +331,7 @@ static int cifs_stats_proc_show(struct seq_file *m, void *v)
 				atomic_read(&totSmBufAllocCount));
 #endif /* CONFIG_CIFS_STATS2 */
 
-	seq_printf(m, "Operations (MIDs): %d\n", midCount.counter);
+	seq_printf(m, "Operations (MIDs): %d\n", atomic_read(&midCount));
 	seq_printf(m,
 		"\n%d session %d share reconnects\n",
 		tcpSesReconnectCount.counter, tconInfoReconnectCount.counter);

fs/cifs/connect.c

@@ -628,7 +628,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 		} else if (!is_valid_oplock_break(smb_buffer, server) &&
 			   !isMultiRsp) {
 			cERROR(1, "No task to wake, unknown frame received! "
-				   "NumMids %d", midCount.counter);
+				   "NumMids %d", atomic_read(&midCount));
 			cifs_dump_mem("Received Data is: ", (char *)smb_buffer,
 				      sizeof(struct smb_hdr));
 #ifdef CONFIG_CIFS_DEBUG2

fs/cifs/transport.c

@@ -61,10 +61,10 @@ AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
 		temp->tsk = current;
 	}
 
-	spin_lock(&GlobalMid_Lock);
-	list_add_tail(&temp->qhead, &server->pending_mid_q);
 	atomic_inc(&midCount);
 	temp->midState = MID_REQUEST_ALLOCATED;
+	spin_lock(&GlobalMid_Lock);
+	list_add_tail(&temp->qhead, &server->pending_mid_q);
 	spin_unlock(&GlobalMid_Lock);
 	return temp;
 }
@@ -78,8 +78,8 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
 	spin_lock(&GlobalMid_Lock);
 	midEntry->midState = MID_FREE;
 	list_del(&midEntry->qhead);
-	atomic_dec(&midCount);
 	spin_unlock(&GlobalMid_Lock);
+	atomic_dec(&midCount);
 	if (midEntry->largeBuf)
 		cifs_buf_release(midEntry->resp_buf);
 	else