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@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

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@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@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