[PATCH -next] fs: cifs: Fix atime update check

[Steve French]

added to cifs-2.6.git for-next (and added Cc: stable) pending additional testing

Adding @Christian Brauner  and @Jeff Layton  since this overlaps a
recent change of theirs.


On Tue, Dec 12, 2023 at 8:25 PM Zizhi Wo <wozizhi at huawei.com> wrote:
>
> Commit 9b9c5bea0b96 ("cifs: do not return atime less than mtime") indicates
> that in cifs, if atime is less than mtime, some apps will break.
> Therefore, it introduce a function to compare this two variables in two
> places where atime is updated. If atime is less than mtime, update it to
> mtime.
>
> However, the patch was handled incorrectly, resulting in atime and mtime
> being exactly equal. A previous commit 69738cfdfa70 ("fs: cifs: Fix atime
> update check vs mtime") fixed one place and forgot to fix another. Fix it.
>
> Fixes: 9b9c5bea0b96 ("cifs: do not return atime less than mtime")
> Signed-off-by: Zizhi Wo <wozizhi at huawei.com>
> ---
>  fs/smb/client/file.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
> index cf17e3dd703e..32a8525415d9 100644
> --- a/fs/smb/client/file.c
> +++ b/fs/smb/client/file.c
> @@ -4671,7 +4671,7 @@ static int cifs_readpage_worker(struct file *file, struct page *page,
>         /* we do not want atime to be less than mtime, it broke some apps */
>         atime = inode_set_atime_to_ts(inode, current_time(inode));
>         mtime = inode_get_mtime(inode);
> -       if (timespec64_compare(&atime, &mtime))
> +       if (timespec64_compare(&atime, &mtime) < 0)
>                 inode_set_atime_to_ts(inode, inode_get_mtime(inode));
>
>         if (PAGE_SIZE > rc)
> --
> 2.39.2
>
>


--
Thanks,

Steve