CIFS: Fix adjustment of credits for MTU requests

Currently for MTU requests we allocate maximum possible credits
in advance and then adjust them according to the request size.
While we were adjusting the number of credits belonging to the
server, we were skipping adjustment of credits belonging to the
request. This patch fixes it by setting request credits to
CreditCharge field value of SMB2 packet header.

Also ask 1 credit more for async read and write operations to
increase parallelism and match the behavior of other operations.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index e57f6aa1d63864131d8559ef77a0eb6f503013a8..b9d7891edaa16cd1f1c8bb542b90d8fade00abdc 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3278,12 +3278,14 @@ smb2_async_readv(struct cifs_readdata *rdata)
        if (rdata->credits) {
                shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
                                                SMB2_MAX_BUFFER_SIZE));
-               shdr->CreditRequest = shdr->CreditCharge;
+               shdr->CreditRequest =
+                       cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
                spin_lock(&server->req_lock);
                server->credits += rdata->credits -
                                                le16_to_cpu(shdr->CreditCharge);
                spin_unlock(&server->req_lock);
                wake_up(&server->request_q);
+               rdata->credits = le16_to_cpu(shdr->CreditCharge);
                flags |= CIFS_HAS_CREDITS;
        }
 
@@ -3555,12 +3557,14 @@ smb2_async_writev(struct cifs_writedata *wdata,
        if (wdata->credits) {
                shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
                                                    SMB2_MAX_BUFFER_SIZE));
-               shdr->CreditRequest = shdr->CreditCharge;
+               shdr->CreditRequest =
+                       cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
                spin_lock(&server->req_lock);
                server->credits += wdata->credits -
                                                le16_to_cpu(shdr->CreditCharge);
                spin_unlock(&server->req_lock);
                wake_up(&server->request_q);
+               wdata->credits = le16_to_cpu(shdr->CreditCharge);
                flags |= CIFS_HAS_CREDITS;
        }