From 03627f6d441761691260c6c1ee92443cab0d9375 Mon Sep 17 00:00:00 2001
From: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Date: Thu, 10 Aug 2023 11:14:58 +0200
Subject: [PATCH] tty: use ssize_t for iterate_tty_read() returned type

References: bsc#1214683 (PREEMPT_RT prerequisite backports)
Patch-mainline: v6.6-rc1
Git-commit: 24b01c5d497ba422f34d381a693d0592e95ad5c3

tty_read() is supposed to return ssize_t. It takes the return value from
iterate_tty_read(). That currently returns int. On the top of that,
iterate_tty_write() already returns ssize_t. So switch
iterate_tty_read() to ssize_t too, so that all three are consistent.

This means 'i' in tty_read() changes its type too. And while changing
that, rename this generic 'i' to more dedicated 'ret'.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230810091510.13006-25-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 | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 692133715f0e..be88c86fb534 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -843,13 +843,13 @@ static void tty_update_time(struct tty_struct *tty, bool mtime)
  * data or clears the cookie. The cookie may be something that the
  * ldisc maintains state for and needs to free.
  */
-static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
-		struct file *file, struct iov_iter *to)
+static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
+				struct file *file, struct iov_iter *to)
 {
-	int retval = 0;
 	void *cookie = NULL;
 	unsigned long offset = 0;
 	char kernel_buf[64];
+	ssize_t retval = 0;
 	size_t count = iov_iter_count(to);
 
 	do {
@@ -912,11 +912,11 @@ static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
  */
 static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
 {
-	int i;
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file_inode(file);
 	struct tty_struct *tty = file_tty(file);
 	struct tty_ldisc *ld;
+	ssize_t ret;
 
 	if (tty_paranoia_check(tty, inode, "tty_read"))
 		return -EIO;
@@ -929,15 +929,15 @@ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
 	ld = tty_ldisc_ref_wait(tty);
 	if (!ld)
 		return hung_up_tty_read(iocb, to);
-	i = -EIO;
+	ret = -EIO;
 	if (ld->ops->read)
-		i = iterate_tty_read(ld, tty, file, to);
+		ret = iterate_tty_read(ld, tty, file, to);
 	tty_ldisc_deref(ld);
 
-	if (i > 0)
+	if (ret > 0)
 		tty_update_time(tty, false);
 
-	return i;
+	return ret;
 }
 
 void tty_write_unlock(struct tty_struct *tty)