From: Oleg Nesterov <oleg@redhat.com>
Date: Thu, 22 Apr 2021 06:43:06 +0000 (+1000)
Subject: aio: simplify read_events()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=261f475dd4ae3952cbce0e28c057ba861cad34d5;p=users%2Fjedix%2Flinux-maple.git

aio: simplify read_events()

Change wait_event_hrtimeout() to not call __wait_event_hrtimeout() if
timeout == 0, this matches other _timeout() helpers in wait.h.

This allows to simplify its only user, read_events(), it no longer needs
to optimize the "until == 0" case by hand.

Note: this patch doesn't use ___wait_cond_timeout because _hrtimeout()
also differs in that it returns 0 if succeeds and -ETIME on timeout.
Perhaps we should change this to make it fully compatible with other
helpers.

Link: http://lkml.kernel.org/r/20190607175413.GA29187@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Eric Wong <e@80x24.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---

diff --git a/fs/aio.c b/fs/aio.c
index 76ce0cc3ee4e..e499cbcef117 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1286,12 +1286,9 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr,
 	 * the ringbuffer empty. So in practice we should be ok, but it's
 	 * something to be aware of when touching this code.
 	 */
-	if (until == 0)
-		aio_read_events(ctx, min_nr, nr, event, &ret);
-	else
-		wait_event_interruptible_hrtimeout(ctx->wait,
-				aio_read_events(ctx, min_nr, nr, event, &ret),
-				until);
+	wait_event_interruptible_hrtimeout(ctx->wait,
+			aio_read_events(ctx, min_nr, nr, event, &ret),
+			until);
 	return ret;
 }
 
diff --git a/include/linux/wait.h b/include/linux/wait.h
index fe10e8570a52..cffb6f8d3b0b 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -555,7 +555,7 @@ do {										\
 ({										\
 	int __ret = 0;								\
 	might_sleep();								\
-	if (!(condition))							\
+	if (!(condition) && (timeout))						\
 		__ret = __wait_event_hrtimeout(wq_head, condition, timeout,	\
 					       TASK_UNINTERRUPTIBLE);		\
 	__ret;									\
@@ -581,7 +581,7 @@ do {										\
 ({										\
 	long __ret = 0;								\
 	might_sleep();								\
-	if (!(condition))							\
+	if (!(condition) && (timeout))						\
 		__ret = __wait_event_hrtimeout(wq, condition, timeout,		\
 					       TASK_INTERRUPTIBLE);		\
 	__ret;									\