summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--fs/cifs/smb2glob.h10
-rw-r--r--fs/cifs/smb2pdu.c18
2 files changed, 27 insertions, 1 deletions
diff --git a/fs/cifs/smb2glob.h b/fs/cifs/smb2glob.h
index 0ffa18094335..238759c146ba 100644
--- a/fs/cifs/smb2glob.h
+++ b/fs/cifs/smb2glob.h
@@ -61,4 +61,14 @@
/* Maximum buffer size value we can send with 1 credit */
#define SMB2_MAX_BUFFER_SIZE 65536
+/*
+ * Maximum number of credits to keep available.
+ * This value is chosen somewhat arbitrarily. The Windows client
+ * defaults to 128 credits, the Windows server allows clients up to
+ * 512 credits, and the NetApp server does not limit clients at all.
+ * Choose a high enough value such that the client shouldn't limit
+ * performance.
+ */
+#define SMB2_MAX_CREDITS_AVAILABLE 32000
+
#endif /* _SMB2_GLOB_H */
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 29e06db5f187..967a7904fb8f 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -100,7 +100,21 @@ smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
hdr->ProtocolId = SMB2_PROTO_NUMBER;
hdr->StructureSize = cpu_to_le16(64);
hdr->Command = smb2_cmd;
- hdr->CreditRequest = cpu_to_le16(2); /* BB make this dynamic */
+ if (tcon && tcon->ses && tcon->ses->server) {
+ struct TCP_Server_Info *server = tcon->ses->server;
+
+ spin_lock(&server->req_lock);
+ /* Request up to 2 credits but don't go over the limit. */
+ if (server->credits >= SMB2_MAX_CREDITS_AVAILABLE)
+ hdr->CreditRequest = cpu_to_le16(0);
+ else
+ hdr->CreditRequest = cpu_to_le16(
+ min_t(int, SMB2_MAX_CREDITS_AVAILABLE -
+ server->credits, 2));
+ spin_unlock(&server->req_lock);
+ } else {
+ hdr->CreditRequest = cpu_to_le16(2);
+ }
hdr->ProcessId = cpu_to_le32((__u16)current->tgid);
if (!tcon)
@@ -2057,6 +2071,7 @@ smb2_async_readv(struct cifs_readdata *rdata)
if (rdata->credits) {
buf->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
SMB2_MAX_BUFFER_SIZE));
+ buf->CreditRequest = buf->CreditCharge;
spin_lock(&server->req_lock);
server->credits += rdata->credits -
le16_to_cpu(buf->CreditCharge);
@@ -2243,6 +2258,7 @@ smb2_async_writev(struct cifs_writedata *wdata,
if (wdata->credits) {
req->hdr.CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
SMB2_MAX_BUFFER_SIZE));
+ req->hdr.CreditRequest = req->hdr.CreditCharge;
spin_lock(&server->req_lock);
server->credits += wdata->credits -
le16_to_cpu(req->hdr.CreditCharge);