[Bluetooth] Convert RFCOMM to use kthread API

This patch does the full kthread conversion for the RFCOMM protocol. It
makes the code slightly simpler and more maintainable.

Based on a patch from Christoph Hellwig <hch@lst.de>

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 21 insertions, 39 deletions

diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index bb7220770f2c..e7ac6ba7ecab 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -33,11 +33,11 @@
 #include <linux/sched.h>
 #include <linux/signal.h>
 #include <linux/init.h>
-#include <linux/freezer.h>
 #include <linux/wait.h>
 #include <linux/device.h>
 #include <linux/net.h>
 #include <linux/mutex.h>
+#include <linux/kthread.h>
 
 #include <net/sock.h>
 #include <asm/uaccess.h>
@@ -68,7 +68,6 @@ static DEFINE_MUTEX(rfcomm_mutex);
 static unsigned long rfcomm_event;
 
 static LIST_HEAD(session_list);
-static atomic_t terminate, running;
 
 static int rfcomm_send_frame(struct rfcomm_session *s, u8 *data, int len);
 static int rfcomm_send_sabm(struct rfcomm_session *s, u8 dlci);
@@ -1850,26 +1849,6 @@ static inline void rfcomm_process_sessions(void)
         rfcomm_unlock();
 }
 
-static void rfcomm_worker(void)
-{
-        BT_DBG("");
-
-        while (!atomic_read(&terminate)) {
-                set_current_state(TASK_INTERRUPTIBLE);
-                if (!test_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event)) {
-                        /* No pending events. Let's sleep.
-                         * Incoming connections and data will wake us up. */
-                        schedule();
-                }
-                set_current_state(TASK_RUNNING);
-
-                /* Process stuff */
-                clear_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event);
-                rfcomm_process_sessions();
-        }
-        return;
-}
-
 static int rfcomm_add_listener(bdaddr_t *ba)
 {
         struct sockaddr_l2 addr;
@@ -1935,22 +1914,28 @@ static void rfcomm_kill_listener(void)
 
 static int rfcomm_run(void *unused)
 {
-        rfcomm_thread = current;
-
-        atomic_inc(&running);
+        BT_DBG("");
 
-        daemonize("krfcommd");
         set_user_nice(current, -10);
 
-        BT_DBG("");
-
         rfcomm_add_listener(BDADDR_ANY);
 
-        rfcomm_worker();
+        while (!kthread_should_stop()) {
+                set_current_state(TASK_INTERRUPTIBLE);
+                if (!test_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event)) {
+                        /* No pending events. Let's sleep.
+                         * Incoming connections and data will wake us up. */
+                        schedule();
+                }
+                set_current_state(TASK_RUNNING);
+
+                /* Process stuff */
+                clear_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event);
+                rfcomm_process_sessions();
+        }
 
         rfcomm_kill_listener();
 
-        atomic_dec(&running);
         return 0;
 }
 
@@ -2059,7 +2044,11 @@ static int __init rfcomm_init(void)
 
         hci_register_cb(&rfcomm_cb);
 
-        kernel_thread(rfcomm_run, NULL, CLONE_KERNEL);
+        rfcomm_thread = kthread_run(rfcomm_run, NULL, "krfcommd");
+        if (IS_ERR(rfcomm_thread)) {
+                hci_unregister_cb(&rfcomm_cb);
+                return PTR_ERR(rfcomm_thread);
+        }
 
         if (class_create_file(bt_class, &class_attr_rfcomm_dlc) < 0)
                 BT_ERR("Failed to create RFCOMM info file");
@@ -2081,14 +2070,7 @@ static void __exit rfcomm_exit(void)
 
         hci_unregister_cb(&rfcomm_cb);
 
-        /* Terminate working thread.
-         * ie. Set terminate flag and wake it up */
-        atomic_inc(&terminate);
-        rfcomm_schedule(RFCOMM_SCHED_STATE);
-
-        /* Wait until thread is running */
-        while (atomic_read(&running))
-                schedule();
+        kthread_stop(rfcomm_thread);
 
 #ifdef CONFIG_BT_RFCOMM_TTY
         rfcomm_cleanup_ttys();