linux-kernel - Re: [PATCH v2] cifs: Silently ignore unknown oplock break handle

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Date:   Wed, 17 Mar 2021 19:17:52 +0530
From:   Rohith Surabattula <rohiths.msft@...il.com>
To:     Tom Talpey <tom@...pey.com>
Cc:     Vincent Whitchurch <vincent.whitchurch@...s.com>,
        Steve French <sfrench@...ba.org>,
        linux-cifs <linux-cifs@...r.kernel.org>, kernel@...s.com,
        samba-technical@...ts.samba.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] cifs: Silently ignore unknown oplock break handle

On 3/16/2021 1:36 PM, Rohith Surabattula wrote:
>> This issue will not be seen once changes related to deferred close for
>> files is committed.

>That may be, but it's irrelevant to this.
Got it.

>> Currently, changes are in review. I will address review comments by this week.

>What do you mean by "in review"? Both threads are active on the
>mailing list. If you or others have something to discuss, please
>post it and don't leave us out of the discussion.

I mean, there is an active thread for patch "deferred close for
files". As I was busy with other activities, I didn't update the
thread. Will update the thread once i get to it.

Regards,
Rohith

On Wed, Mar 17, 2021 at 12:59 AM Tom Talpey <tom@...pey.com> wrote:
>
> On 3/16/2021 1:36 PM, Rohith Surabattula wrote:
> > This issue will not be seen once changes related to deferred close for
> > files is committed.
>
> That may be, but it's irrelevant to this.
>
> > Currently, changes are in review. I will address review comments by this week.
>
> What do you mean by "in review"? Both threads are active on the
> mailing list. If you or others have something to discuss, please
> post it and don't leave us out of the discussion.
>
> Tom.
>
>
> > Regards,
> > Rohith
> >
> > On Tue, Mar 16, 2021 at 9:33 PM Tom Talpey <tom@...pey.com> wrote:
> >>
> >> On 3/16/2021 8:48 AM, Vincent Whitchurch via samba-technical wrote:
> >>> Make SMB2 not print out an error when an oplock break is received for an
> >>> unknown handle, similar to SMB1.  The SMB2 lease break path is not
> >>> affected by this patch.
> >>>
> >>> Without this, a program which writes to a file from one thread, and
> >>> opens, reads, and writes the same file from another thread triggers the
> >>> below errors several times a minute when run against a Samba server
> >>> configured with "smb2 leases = no".
> >>>
> >>>    CIFS: VFS: \\192.168.0.1 No task to wake, unknown frame received! NumMids 2
> >>>    00000000: 424d53fe 00000040 00000000 00000012  .SMB@...........
> >>>    00000010: 00000001 00000000 ffffffff ffffffff  ................
> >>>    00000020: 00000000 00000000 00000000 00000000  ................
> >>>    00000030: 00000000 00000000 00000000 00000000  ................
> >>>
> >>> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@...s.com>
> >>> ---
> >>>
> >>> Notes:
> >>>       v2:
> >>>       - Drop change to lease break
> >>>       - Rewrite commit message
> >>>
> >>>    fs/cifs/smb2misc.c | 2 +-
> >>>    1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
> >>> index 60d4bd1eae2b..4d8576e202e3 100644
> >>> --- a/fs/cifs/smb2misc.c
> >>> +++ b/fs/cifs/smb2misc.c
> >>> @@ -755,7 +755,7 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
> >>>        }
> >>>        spin_unlock(&cifs_tcp_ses_lock);
> >>>        cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
> >>> -     return false;
> >>> +     return true;
> >>>    }
> >>>
> >>>    void
> >>>
> >>
> >> As an oplock-only approach, it looks good. But the old cifs_dbg message
> >> "non-existent connection" is possibly misleading, since the connection
> >> may be perfectly fine.
> >>
> >> When breaking the loop successfully, the code emits
> >>          cifs_dbg(FYI, "file id match, oplock break\n");
> >> so perhaps
> >>          cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
> >> ?
> >>
> >> Tom.
> >