From 7d3dec635561dc81aefe6e7002802dabc5dc22fc Mon Sep 17 00:00:00 2001
From: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Date: Thu, 10 Aug 2023 11:14:57 +0200
Subject: [PATCH] tty: use min() in iterate_tty_write()

References: bsc#1214683 (PREEMPT_RT prerequisite backports)
Patch-mainline: v6.6-rc1
Git-commit: ccc8dc00a24bb657b6a6f8adbfbb535365b4ba3d

It simplifies the code. The "price" is we have to unify 'chunk' to be
size_t the same as 'count' is. But that change is actually correct.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230810091510.13006-24-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 drivers/tty/tty_io.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 4319a3e04fd9..692133715f0e 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -964,9 +964,8 @@ int tty_write_lock(struct tty_struct *tty, bool ndelay)
 static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty,
 				 struct file *file, struct iov_iter *from)
 {
-	size_t count = iov_iter_count(from);
+	size_t chunk, count = iov_iter_count(from);
 	ssize_t ret, written = 0;
-	unsigned int chunk;
 
 	ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
 	if (ret < 0)
@@ -1010,10 +1009,7 @@ static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty,
 
 	/* Do the write .. */
 	for (;;) {
-		size_t size = count;
-
-		if (size > chunk)
-			size = chunk;
+		size_t size = min(chunk, count);
 
 		ret = -EFAULT;
 		if (copy_from_iter(tty->write_buf, size, from) != size)