Re: [PATCH AUTOSEL 4.20 65/77] CIFS: Do not assume one credit for async responses

Sasha Levin
2019-02-27T17:54:15Z

On Fri, Feb 15, 2019 at 08:10:47PM +0000, Pavel Shilovskiy wrote:
>чт, 14 февр. 2019 г. в 18:40, Sasha 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 = mid->callback_data;
>> struct smb2_echo_rsp *rsp = (struct smb2_echo_rsp *)mid->resp_buf;
>> - unsigned int credits_received = 1;
>> + unsigned int credits_received = 0;
>>
>> - if (mid->mid_state == MID_RESPONSE_RECEIVED)
>> + if (mid->mid_state == MID_RESPONSE_RECEIVED
>> + || mid->mid_state == MID_RESPONSE_MALFORMED)
>> credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
>>
>> DeleteMidQEntry(mid);
>> @@ -3093,7 +3094,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
>> struct TCP_Server_Info *server = tcon->ses->server;
>> struct smb2_sync_hdr *shdr =
>> (struct smb2_sync_hdr *)rdata->iov[0].iov_base;
>> - unsigned int credits_received = 1;
>> + unsigned int credits_received = 0;
>> struct smb_rqst rqst = { .rq_iov = rdata->iov,
>> .rq_nvec = 2,
>> .rq_pages = 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 = le16_to_cpu(shdr->CreditRequest);
>> + /* fall through */
>> default:
>> if (rdata->result != -ENODATA)
>> rdata->result = -EIO;
>> @@ -3325,7 +3329,7 @@ smb2_writev_callback(struct mid_q_entry *mid)
>> struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
>> unsigned int written;
>> struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf;
>> - unsigned int credits_received = 1;
>> + unsigned int credits_received = 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 = -EAGAIN;
>> break;
>> + case MID_RESPONSE_MALFORMED:
>> + credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
>> + /* fall through */
>> default:
>> wdata->result = -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!

--
Thanks,
Sasha