CIFS: Use multicredits for SMB 2.1/3 writes
If we negotiate SMB 2.1 and higher version of the protocol and
a server supports large write buffer size, we need to consume 1
credit per 65536 bytes. So, we need to know how many credits
we have and obtain the required number of them before constructing
a writedata structure in writepages and iovec write.
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index da7aa62..be7b2eb 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -108,7 +108,6 @@
if (!tcon)
goto out;
- /* BB FIXME when we do write > 64K add +1 for every 64K in req or rsp */
/* GLOBAL_CAP_LARGE_MTU will only be set if dialect > SMB2.02 */
/* See sections 2.2.4 and 3.2.4.1.5 of MS-SMB2 */
if ((tcon->ses) &&
@@ -1892,15 +1891,25 @@
smb2_async_writev(struct cifs_writedata *wdata,
void (*release)(struct kref *kref))
{
- int rc = -EACCES;
+ int rc = -EACCES, flags = 0;
struct smb2_write_req *req = NULL;
struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
+ struct TCP_Server_Info *server = tcon->ses->server;
struct kvec iov;
struct smb_rqst rqst;
rc = small_smb2_init(SMB2_WRITE, tcon, (void **) &req);
- if (rc)
+ if (rc) {
+ if (rc == -EAGAIN && wdata->credits) {
+ /* credits was reset by reconnect */
+ wdata->credits = 0;
+ /* reduce in_flight value since we won't send the req */
+ spin_lock(&server->req_lock);
+ server->in_flight--;
+ spin_unlock(&server->req_lock);
+ }
goto async_writev_out;
+ }
req->hdr.ProcessId = cpu_to_le32(wdata->cfile->pid);
@@ -1933,9 +1942,20 @@
inc_rfc1001_len(&req->hdr, wdata->bytes - 1 /* Buffer */);
+ if (wdata->credits) {
+ req->hdr.CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
+ SMB2_MAX_BUFFER_SIZE));
+ spin_lock(&server->req_lock);
+ server->credits += wdata->credits -
+ le16_to_cpu(req->hdr.CreditCharge);
+ spin_unlock(&server->req_lock);
+ wake_up(&server->request_q);
+ flags = CIFS_HAS_CREDITS;
+ }
+
kref_get(&wdata->refcount);
- rc = cifs_call_async(tcon->ses->server, &rqst, NULL,
- smb2_writev_callback, wdata, 0);
+ rc = cifs_call_async(server, &rqst, NULL, smb2_writev_callback, wdata,
+ flags);
if (rc) {
kref_put(&wdata->refcount, release);