On Thu, May 10, 2018 at 11:04:14AM -0500, Steve French via samba-technical wrote:
> As with NFS, which ignores sync on directory handles,
> fsync on a directory handle is a noop for CIFS/SMB3.
> Do not return an error on it. It breaks some database
> apps otherwise.
Thanks for this. I now have an smbtorture test that
shows we handle flush on directories incorrectly.
Patch to follow.
Jeremy.
> --
> Thanks,
>
> Steve
> From 6112a4967573f9a347f7abc02e80423851b73737 Mon Sep 17 00:00:00 2001
> From: Steve French <smfrench@xxxxxxxxx>
> Date: Thu, 10 May 2018 10:59:37 -0500
> Subject: [PATCH] smb3: directory sync should not return an error
>
> As with NFS, which ignores sync on directory handles,
> fsync on a directory handle is a noop for CIFS/SMB3.
> Do not return an error on it. It breaks some database
> apps otherwise.
>
> Signed-off-by: Steve French <smfrench@xxxxxxxxx>
> CC: Stable <stable@xxxxxxxxxxxxxxx>
> ---
> fs/cifs/cifsfs.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index ed8e181927d6..8e41186d9923 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -1049,6 +1049,18 @@ ssize_t cifs_file_copychunk_range(unsigned int xid,
> return rc;
> }
>
> +/*
> + * Directory operations under CIFS/SMB2/SMB3 are synchronous, so fsync()
> + * is a dummy operation.
> + */
> +int cifs_dir_fsync(struct file *file, loff_t start, loff_t end, int datasync)
> +{
> + cifs_dbg(FYI, "Sync directory - name: %pD datasync: 0x%x\n",
> + file, datasync);
> +
> + return 0;
> +}
> +
> static ssize_t cifs_copy_file_range(struct file *src_file, loff_t off,
> struct file *dst_file, loff_t destoff,
> size_t len, unsigned int flags)
> @@ -1183,6 +1195,7 @@ const struct file_operations cifs_dir_ops = {
> .copy_file_range = cifs_copy_file_range,
> .clone_file_range = cifs_clone_file_range,
> .llseek = generic_file_llseek,
> + .fsync = cifs_dir_fsync,
> };
>
> static void
> --
> 2.17.0
>
