CIFS: Fix adjustment of credits for MTU requests

commit b983f7e92348d7e7d091db1b78b7915e9dd3d63a upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 1581e8668b091a9713122cd85fb6f3566660fcbf..c0f8087d981913d0e3bf48a490e7c8f3de217e4b 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2632,12 +2632,14 @@ 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;
        }
 
@@ -2842,12 +2844,14 @@ 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;
        }