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From:   Pavel Shilovskiy <pshilov@microsoft.com>
To:     Sasha Levin <sashal@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>
CC:     Steven French <Steven.French@microsoft.com>,
        "linux-cifs@vger.kernel.org" <linux-cifs@vger.kernel.org>
Subject: RE: [PATCH AUTOSEL 4.20 65/77] CIFS: Do not assume one credit for
 async responses
Thread-Topic: [PATCH AUTOSEL 4.20 65/77] CIFS: Do not assume one credit for
 async responses
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Date:   Fri, 15 Feb 2019 20:10:47 +0000
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 <20190215020855.176727-65-sashal@kernel.org>
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=DE=D4, 14 =C6=C5=D7=D2. 2019 =C7. =D7 18:40, Sasha Levin <sashal@kernel.or=
g>:
>
> 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->resp_b=
uf;
> -       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.CreditRequ=
est);
>
>         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->resp=
_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.CreditRequ=
est);
> +               /* 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/

Best regards,
Pavel Shilovsky