From 15f242bb65b89d5f1ff990668a586fdf1307b2c8 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hughd@google.com>
Date: Wed, 10 Aug 2022 21:55:36 -0700
Subject: [PATCH] mm/shmem: tmpfs fallocate use file_modified()

5.18 fixed the btrfs and ext4 fallocates to use file_modified(), as xfs
was already doing, to drop privileges: and fstests generic/{683,684,688}
expect this.  There's no need to argue over keep-size allocation (which
could just update ctime): fix shmem_fallocate() to behave the same way.

Link: https://lkml.kernel.org/r/39c5e62-4896-7795-c0a0-f79c50d4909@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Radoslaw Burny <rburny@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/shmem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 170b4078420f5..ce2090744c5e4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2839,12 +2839,13 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 
 	if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size)
 		i_size_write(inode, offset + len);
-	inode->i_ctime = current_time(inode);
 undone:
 	spin_lock(&inode->i_lock);
 	inode->i_private = NULL;
 	spin_unlock(&inode->i_lock);
 out:
+	if (!error)
+		file_modified(file);
 	inode_unlock(inode);
 	return error;
 }