[PATCH] cifs/smb3: Fix data inconsistent when zero file range

[Pavel Shilovsky]

пт, 19 июн. 2020 г. в 22:04, Zhang Xiaoxu <zhangxiaoxu5 at huawei.com>:
>
> CIFS implements the fallocate(FALLOC_FL_ZERO_RANGE) with send SMB
> ioctl(FSCTL_SET_ZERO_DATA) to server. It just set the range of the
> remote file to zero, but local page cache not update, then the data
> inconsistent with server, which leads the xfstest generic/008 failed.
>
> So we need to remove the local page caches before send SMB
> ioctl(FSCTL_SET_ZERO_DATA) to server. After next read, it will
> re-cache it.
>
> Reported-by: Hulk Robot <hulkci at huawei.com>
> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5 at huawei.com>
> ---
>  fs/cifs/smb2ops.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 736d86b8a910..250b51aca514 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -3187,6 +3187,11 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon,
>         trace_smb3_zero_enter(xid, cfile->fid.persistent_fid, tcon->tid,
>                               ses->Suid, offset, len);
>
> +       /*
> +        * We zero the range through ioctl, so we need remove the page caches
> +        * first, otherwise the data may be inconsistent with the server.
> +        */
> +       truncate_pagecache_range(inode, offset, offset + len - 1);
>
>         /* if file not oplocked can't be sure whether asking to extend size */
>         if (!CIFS_CACHE_READ(cifsi))
> --
> 2.25.4
>

Looks good!

Reviewed-by: Pavel Shilovsky <pshilov at microsoft.com>

Don't we need to do the same for smb3_punch_hole()?

--
Best regards,
Pavel Shilovsky