sched/wait: Make the __wait_event*() interface more friendly

Change all __wait_event*() implementations to match the corresponding
wait_event*() signature for convenience.

In particular this does away with the weird 'ret' logic. Since there
are __wait_event*() users this requires we update them too.

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131002092529.042563462@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

5 files changed, 73 insertions, 81 deletions

diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c
index d763f11e35e2..2c12ea1668d1 100644
--- a/arch/mips/kernel/rtlx.c
+++ b/arch/mips/kernel/rtlx.c
@@ -172,8 +172,9 @@ int rtlx_open(int index, int can_sleep)
         if (rtlx == NULL) {
                 if( (p = vpe_get_shared(tclimit)) == NULL) {
                     if (can_sleep) {
-                        __wait_event_interruptible(channel_wqs[index].lx_queue,
-                                (p = vpe_get_shared(tclimit)), ret);
+                        ret = __wait_event_interruptible(
+                                        channel_wqs[index].lx_queue,
+                                        (p = vpe_get_shared(tclimit)));
                         if (ret)
                                 goto out_fail;
                     } else {
@@ -263,11 +264,10 @@ unsigned int rtlx_read_poll(int index, int can_sleep)
         /* data available to read? */
         if (chan->lx_read == chan->lx_write) {
                 if (can_sleep) {
-                        int ret = 0;
-
-                        __wait_event_interruptible(channel_wqs[index].lx_queue,
+                        int ret = __wait_event_interruptible(
+                                channel_wqs[index].lx_queue,
                                 (chan->lx_read != chan->lx_write) ||
-                                sp_stopping, ret);
+                                sp_stopping);
                         if (ret)
                                 return ret;
 
@@ -440,14 +440,13 @@ static ssize_t file_write(struct file *file, const char __user * buffer,
 
         /* any space left... */
         if (!rtlx_write_poll(minor)) {
-                int ret = 0;
+                int ret;
 
                 if (file->f_flags & O_NONBLOCK)
                         return -EAGAIN;
 
-                __wait_event_interruptible(channel_wqs[minor].rt_queue,
-                                           rtlx_write_poll(minor),
-                                           ret);
+                ret = __wait_event_interruptible(channel_wqs[minor].rt_queue,
+                                           rtlx_write_poll(minor));
                 if (ret)
                         return ret;
         }
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 6e803291028f..633cac77f9f9 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -672,14 +672,14 @@ static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
 #define wait_event_interruptible_tty(tty, wq, condition)                \
 ({                                                                      \
         int __ret = 0;                                                  \
-        if (!(condition)) {                                             \
-                __wait_event_interruptible_tty(tty, wq, condition, __ret);      \
-        }                                                               \
+        if (!(condition))                                               \
+                __ret = __wait_event_interruptible_tty(tty, wq,         \
+                                                       condition);      \
         __ret;                                                          \
 })
 
-#define __wait_event_interruptible_tty(tty, wq, condition, ret)         \
-        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, ret,        \
+#define __wait_event_interruptible_tty(tty, wq, condition)              \
+        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,          \
                         tty_unlock(tty);                                \
                         schedule();                                     \
                         tty_lock(tty))
diff --git a/include/linux/wait.h b/include/linux/wait.h
index c065e8af9749..bd4bd7b479b6 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -179,24 +179,23 @@ wait_queue_head_t *bit_waitqueue(void *, int);
 #define wake_up_interruptible_sync_poll(x, m)                           \
         __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
 
-#define ___wait_cond_timeout(condition, ret)                            \
+#define ___wait_cond_timeout(condition)                                 \
 ({                                                                      \
         bool __cond = (condition);                                      \
-        if (__cond && !ret)                                             \
-                ret = 1;                                                \
-        __cond || !ret;                                                 \
+        if (__cond && !__ret)                                           \
+                __ret = 1;                                              \
+        __cond || !__ret;                                               \
 })
 
 #define ___wait_signal_pending(state)                                   \
         ((state == TASK_INTERRUPTIBLE && signal_pending(current)) ||    \
          (state == TASK_KILLABLE && fatal_signal_pending(current)))
 
-#define ___wait_nop_ret         int ret __always_unused
-
 #define ___wait_event(wq, condition, state, exclusive, ret, cmd)        \
-do {                                                                    \
+({                                                                      \
         __label__ __out;                                                \
         DEFINE_WAIT(__wait);                                            \
+        long __ret = ret;                                               \
                                                                         \
         for (;;) {                                                      \
                 if (exclusive)                                          \
@@ -208,7 +207,7 @@ do {									\
                         break;                                          \
                                                                         \
                 if (___wait_signal_pending(state)) {                    \
-                        ret = -ERESTARTSYS;                             \
+                        __ret = -ERESTARTSYS;                           \
                         if (exclusive) {                                \
                                 abort_exclusive_wait(&wq, &__wait,      \
                                                      state, NULL);      \
@@ -220,12 +219,12 @@ do {									\
                 cmd;                                                    \
         }                                                               \
         finish_wait(&wq, &__wait);                                      \
-__out:  ;                                                               \
-} while (0)
+__out:  __ret;                                                          \
+})
 
 #define __wait_event(wq, condition)                                     \
-        ___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0,           \
-                      ___wait_nop_ret, schedule())
+        (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0,  \
+                            schedule())
 
 /**
  * wait_event - sleep until a condition gets true
@@ -246,10 +245,10 @@ do {									\
         __wait_event(wq, condition);                                    \
 } while (0)
 
-#define __wait_event_timeout(wq, condition, ret)                        \
-        ___wait_event(wq, ___wait_cond_timeout(condition, ret),         \
-                      TASK_UNINTERRUPTIBLE, 0, ret,                     \
-                      ret = schedule_timeout(ret))
+#define __wait_event_timeout(wq, condition, timeout)                    \
+        ___wait_event(wq, ___wait_cond_timeout(condition),              \
+                      TASK_UNINTERRUPTIBLE, 0, timeout,                 \
+                      __ret = schedule_timeout(__ret))
 
 /**
  * wait_event_timeout - sleep until a condition gets true or a timeout elapses
@@ -272,12 +271,12 @@ do {									\
 ({                                                                      \
         long __ret = timeout;                                           \
         if (!(condition))                                               \
-                __wait_event_timeout(wq, condition, __ret);             \
+                __ret = __wait_event_timeout(wq, condition, timeout);   \
         __ret;                                                          \
 })
 
-#define __wait_event_interruptible(wq, condition, ret)                  \
-        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, ret,        \
+#define __wait_event_interruptible(wq, condition)                       \
+        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,          \
                       schedule())
 
 /**
@@ -299,14 +298,14 @@ do {									\
 ({                                                                      \
         int __ret = 0;                                                  \
         if (!(condition))                                               \
-                __wait_event_interruptible(wq, condition, __ret);       \
+                __ret = __wait_event_interruptible(wq, condition);      \
         __ret;                                                          \
 })
 
-#define __wait_event_interruptible_timeout(wq, condition, ret)          \
-        ___wait_event(wq, ___wait_cond_timeout(condition, ret),         \
-                      TASK_INTERRUPTIBLE, 0, ret,                       \
-                      ret = schedule_timeout(ret))
+#define __wait_event_interruptible_timeout(wq, condition, timeout)      \
+        ___wait_event(wq, ___wait_cond_timeout(condition),              \
+                      TASK_INTERRUPTIBLE, 0, timeout,                   \
+                      __ret = schedule_timeout(__ret))
 
 /**
  * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
@@ -330,7 +329,8 @@ do {									\
 ({                                                                      \
         long __ret = timeout;                                           \
         if (!(condition))                                               \
-                __wait_event_interruptible_timeout(wq, condition, __ret); \
+                __ret = __wait_event_interruptible_timeout(wq,          \
+                                                condition, timeout);    \
         __ret;                                                          \
 })
 
@@ -347,7 +347,7 @@ do {									\
                                        current->timer_slack_ns,         \
                                        HRTIMER_MODE_REL);               \
                                                                         \
-        ___wait_event(wq, condition, state, 0, __ret,                   \
+        __ret = ___wait_event(wq, condition, state, 0, 0,               \
                 if (!__t.task) {                                        \
                         __ret = -ETIME;                                 \
                         break;                                          \
@@ -409,15 +409,15 @@ do {									\
         __ret;                                                          \
 })
 
-#define __wait_event_interruptible_exclusive(wq, condition, ret)        \
-        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, ret,        \
+#define __wait_event_interruptible_exclusive(wq, condition)             \
+        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,          \
                       schedule())
 
 #define wait_event_interruptible_exclusive(wq, condition)               \
 ({                                                                      \
         int __ret = 0;                                                  \
         if (!(condition))                                               \
-                __wait_event_interruptible_exclusive(wq, condition, __ret);\
+                __ret = __wait_event_interruptible_exclusive(wq, condition);\
         __ret;                                                          \
 })
 
@@ -570,8 +570,8 @@ do {									\
 
 
 
-#define __wait_event_killable(wq, condition, ret)                       \
-        ___wait_event(wq, condition, TASK_KILLABLE, 0, ret, schedule())
+#define __wait_event_killable(wq, condition)                            \
+        ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
 
 /**
  * wait_event_killable - sleep until a condition gets true
@@ -592,18 +592,17 @@ do {									\
 ({                                                                      \
         int __ret = 0;                                                  \
         if (!(condition))                                               \
-                __wait_event_killable(wq, condition, __ret);            \
+                __ret = __wait_event_killable(wq, condition);           \
         __ret;                                                          \
 })
 
 
 #define __wait_event_lock_irq(wq, condition, lock, cmd)                 \
-        ___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0,           \
-                      ___wait_nop_ret,                                  \
-                      spin_unlock_irq(&lock);                           \
-                      cmd;                                              \
-                      schedule();                                       \
-                      spin_lock_irq(&lock))
+        (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0,  \
+                            spin_unlock_irq(&lock);                     \
+                            cmd;                                        \
+                            schedule();                                 \
+                            spin_lock_irq(&lock))
 
 /**
  * wait_event_lock_irq_cmd - sleep until a condition gets true. The
@@ -663,11 +662,11 @@ do {									\
 } while (0)
 
 
-#define __wait_event_interruptible_lock_irq(wq, condition, lock, ret, cmd) \
-        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, ret,           \
-                      spin_unlock_irq(&lock);                              \
-                      cmd;                                                 \
-                      schedule();                                          \
+#define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd)   \
+        ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,          \
+                      spin_unlock_irq(&lock);                           \
+                      cmd;                                              \
+                      schedule();                                       \
                       spin_lock_irq(&lock))
 
 /**
@@ -698,10 +697,9 @@ do {									\
 #define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \
 ({                                                                      \
         int __ret = 0;                                                  \
-                                                                        \
         if (!(condition))                                               \
-                __wait_event_interruptible_lock_irq(wq, condition,      \
-                                                    lock, __ret, cmd);  \
+                __ret = __wait_event_interruptible_lock_irq(wq,         \
+                                                condition, lock, cmd);  \
         __ret;                                                          \
 })
 
@@ -730,18 +728,18 @@ do {									\
 #define wait_event_interruptible_lock_irq(wq, condition, lock)          \
 ({                                                                      \
         int __ret = 0;                                                  \
-                                                                        \
         if (!(condition))                                               \
-                __wait_event_interruptible_lock_irq(wq, condition,      \
-                                                    lock, __ret, );     \
+                __ret = __wait_event_interruptible_lock_irq(wq,         \
+                                                condition, lock,)       \
         __ret;                                                          \
 })
 
-#define __wait_event_interruptible_lock_irq_timeout(wq, condition, lock, ret) \
-        ___wait_event(wq, ___wait_cond_timeout(condition, ret),               \
-                      TASK_INTERRUPTIBLE, 0, ret,                             \
-                      spin_unlock_irq(&lock);                                 \
-                      ret = schedule_timeout(ret);                            \
+#define __wait_event_interruptible_lock_irq_timeout(wq, condition,      \
+                                                    lock, timeout)      \
+        ___wait_event(wq, ___wait_cond_timeout(condition),              \
+                      TASK_INTERRUPTIBLE, 0, ret,                       \
+                      spin_unlock_irq(&lock);                           \
+                      __ret = schedule_timeout(__ret);                  \
                       spin_lock_irq(&lock));
 
 /**
@@ -771,11 +769,10 @@ do {									\
 #define wait_event_interruptible_lock_irq_timeout(wq, condition, lock,  \
                                                   timeout)              \
 ({                                                                      \
-        int __ret = timeout;                                            \
-                                                                        \
+        long __ret = timeout;                                           \
         if (!(condition))                                               \
-                __wait_event_interruptible_lock_irq_timeout(            \
-                                        wq, condition, lock, __ret);    \
+                __ret = __wait_event_interruptible_lock_irq_timeout(    \
+                                        wq, condition, lock, timeout);  \
         __ret;                                                          \
 })
 
diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
index 0578d4fa00a9..0f676908d15b 100644
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -2563,9 +2563,8 @@ bed:
                                   jiffies + msecs_to_jiffies(val));
 
                         /* Wait for IR-LMP to call us back */
-                        __wait_event_interruptible(self->query_wait,
-                              (self->cachedaddr != 0 || self->errno == -ETIME),
-                                                   err);
+                        err = __wait_event_interruptible(self->query_wait,
+                              (self->cachedaddr != 0 || self->errno == -ETIME));
 
                         /* If watchdog is still activated, kill it! */
                         del_timer(&(self->watchdog));
diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index f4484719f3e6..f63c2388f38d 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -1637,12 +1637,9 @@ static int sync_thread_master(void *data)
                         continue;
                 }
                 while (ip_vs_send_sync_msg(tinfo->sock, sb->mesg) < 0) {
-                        int ret = 0;
-
-                        __wait_event_interruptible(*sk_sleep(sk),
+                        int ret = __wait_event_interruptible(*sk_sleep(sk),
                                                    sock_writeable(sk) ||
-                                                   kthread_should_stop(),
-                                                   ret);
+                                                   kthread_should_stop());
                         if (unlikely(kthread_should_stop()))
                                 goto done;
                 }