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From:   Pavel Shilovsky <piastryyy@gmail.com>
Date:   Wed, 27 Feb 2019 11:39:31 -0800
Message-ID: <CAKywueT1fm2F1ggeRZhjGxZgd=k1Hy_1Ns4Eom3hLq-oaRnBvA@mail.gmail.com>
Subject: Re: [PATCH AUTOSEL 4.20 65/77] CIFS: Do not assume one credit for
 async responses
To:     Sasha Levin <sashal@kernel.org>
Cc:     Pavel Shilovskiy <pshilov@microsoft.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>,
        Steven French <Steven.French@microsoft.com>,
        "linux-cifs@vger.kernel.org" <linux-cifs@vger.kernel.org>
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=D1=81=D1=80, 27 =D1=84=D0=B5=D0=B2=D1=80. 2019 =D0=B3. =D0=B2 09:54, Sasha=
 Levin <sashal@kernel.org>:
>
> On Fri, Feb 15, 2019 at 08:10:47PM +0000, Pavel Shilovskiy wrote:
> >=D1=87=D1=82, 14 =D1=84=D0=B5=D0=B2=D1=80. 2019 =D0=B3. =D0=B2 18:40, Sa=
sha Levin <sashal@kernel.org>:
> >>
> >> From: Pavel Shilovsky <pshilov@microsoft.com>
> >>
> >> [ Upstream commit 0fd1d37b0501efc6e295f56ab55cdaff784aa50c ]
> >>
> >> If we don't receive a response we can't assume that the server
> >> granted one credit. Assume zero credits in such cases.
> >>
> >> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
> >> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
> >> Signed-off-by: Steve French <stfrench@microsoft.com>
> >> Signed-off-by: Sasha Levin <sashal@kernel.org>
> >> ---
> >>  fs/cifs/smb2pdu.c | 15 +++++++++++----
> >>  1 file changed, 11 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> >> index d1ae7cdb236d..3c44c51310c4 100644
> >> --- a/fs/cifs/smb2pdu.c
> >> +++ b/fs/cifs/smb2pdu.c
> >> @@ -2834,9 +2834,10 @@ smb2_echo_callback(struct mid_q_entry *mid)
> >>  {
> >>         struct TCP_Server_Info *server =3D mid->callback_data;
> >>         struct smb2_echo_rsp *rsp =3D (struct smb2_echo_rsp *)mid->res=
p_buf;
> >> -       unsigned int credits_received =3D 1;
> >> +       unsigned int credits_received =3D 0;
> >>
> >> -       if (mid->mid_state =3D=3D MID_RESPONSE_RECEIVED)
> >> +       if (mid->mid_state =3D=3D MID_RESPONSE_RECEIVED
> >> +           || mid->mid_state =3D=3D MID_RESPONSE_MALFORMED)
> >>                 credits_received =3D le16_to_cpu(rsp->sync_hdr.CreditR=
equest);
> >>
> >>         DeleteMidQEntry(mid);
> >> @@ -3093,7 +3094,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
> >>         struct TCP_Server_Info *server =3D tcon->ses->server;
> >>         struct smb2_sync_hdr *shdr =3D
> >>                                 (struct smb2_sync_hdr *)rdata->iov[0].=
iov_base;
> >> -       unsigned int credits_received =3D 1;
> >> +       unsigned int credits_received =3D 0;
> >>         struct smb_rqst rqst =3D { .rq_iov =3D rdata->iov,
> >>                                  .rq_nvec =3D 2,
> >>                                  .rq_pages =3D rdata->pages,
> >> @@ -3132,6 +3133,9 @@ smb2_readv_callback(struct mid_q_entry *mid)
> >>                 task_io_account_read(rdata->got_bytes);
> >>                 cifs_stats_bytes_read(tcon, rdata->got_bytes);
> >>                 break;
> >> +       case MID_RESPONSE_MALFORMED:
> >> +               credits_received =3D le16_to_cpu(shdr->CreditRequest);
> >> +               /* fall through */
> >>         default:
> >>                 if (rdata->result !=3D -ENODATA)
> >>                         rdata->result =3D -EIO;
> >> @@ -3325,7 +3329,7 @@ smb2_writev_callback(struct mid_q_entry *mid)
> >>         struct cifs_tcon *tcon =3D tlink_tcon(wdata->cfile->tlink);
> >>         unsigned int written;
> >>         struct smb2_write_rsp *rsp =3D (struct smb2_write_rsp *)mid->r=
esp_buf;
> >> -       unsigned int credits_received =3D 1;
> >> +       unsigned int credits_received =3D 0;
> >>
> >>         switch (mid->mid_state) {
> >>         case MID_RESPONSE_RECEIVED:
> >> @@ -3353,6 +3357,9 @@ smb2_writev_callback(struct mid_q_entry *mid)
> >>         case MID_RETRY_NEEDED:
> >>                 wdata->result =3D -EAGAIN;
> >>                 break;
> >> +       case MID_RESPONSE_MALFORMED:
> >> +               credits_received =3D le16_to_cpu(rsp->sync_hdr.CreditR=
equest);
> >> +               /* fall through */
> >>         default:
> >>                 wdata->result =3D -EIO;
> >>                 break;
> >> --
> >> 2.19.1
> >>
> >
> >Can you also apply the following patch to 4.20.y and 4.19.y, please?
> >
> >https://patchwork.ozlabs.org/patch/1030180/
>
> I'll queue it up for the next cycle as it has dependencies on stable@
> commits that didn't make it in yet and I don't want to mess up with
> Greg's flow. Thanks you!

It seems that this one has already been merged to 4.20.11:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=
=3Dlinux-4.20.y&id=3D7cb453e5a88169b2a5cec1e00778fc969efd1a77

So, between those two stable kernels only 4.19 doesn't have the patch.

--
Best regards,
Pavel Shilovsky