ksmbd: fix wrong smbd max read/write size check

smb-direct max read/write size can be different with smb2 max read/write
size. So smb2_read() can return error by wrong max read/write size check.
This patch use smb_direct_max_read_write_size for this check in
smb-direct read/write().
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/smb2pdu.c

@@ -6183,6 +6183,8 @@ int smb2_read(struct ksmbd_work *work)
 	size_t length, mincount;
 	ssize_t nbytes = 0, remain_bytes = 0;
 	int err = 0;
+	bool is_rdma_channel = false;
+	unsigned int max_read_size = conn->vals->max_read_size;
 
 	WORK_BUFFERS(work, req, rsp);
 
@@ -6194,6 +6196,11 @@ int smb2_read(struct ksmbd_work *work)
 
 	if (req->Channel == SMB2_CHANNEL_RDMA_V1_INVALIDATE ||
 	    req->Channel == SMB2_CHANNEL_RDMA_V1) {
+		is_rdma_channel = true;
+		max_read_size = get_smbd_max_read_write_size();
+	}
+
+	if (is_rdma_channel == true) {
 		unsigned int ch_offset = le16_to_cpu(req->ReadChannelInfoOffset);
 
 		if (ch_offset < offsetof(struct smb2_read_req, Buffer)) {
@@ -6225,9 +6232,9 @@ int smb2_read(struct ksmbd_work *work)
 	length = le32_to_cpu(req->Length);
 	mincount = le32_to_cpu(req->MinimumCount);
 
-	if (length > conn->vals->max_read_size) {
+	if (length > max_read_size) {
 		ksmbd_debug(SMB, "limiting read size to max size(%u)\n",
-			    conn->vals->max_read_size);
+			    max_read_size);
 		err = -EINVAL;
 		goto out;
 	}
@@ -6259,8 +6266,7 @@ int smb2_read(struct ksmbd_work *work)
 	ksmbd_debug(SMB, "nbytes %zu, offset %lld mincount %zu\n",
 		    nbytes, offset, mincount);
 
-	if (req->Channel == SMB2_CHANNEL_RDMA_V1_INVALIDATE ||
-	    req->Channel == SMB2_CHANNEL_RDMA_V1) {
+	if (is_rdma_channel == true) {
 		/* write data to the client using rdma channel */
 		remain_bytes = smb2_read_rdma_channel(work, req,
 						      work->aux_payload_buf,
@@ -6421,8 +6427,9 @@ int smb2_write(struct ksmbd_work *work)
 	size_t length;
 	ssize_t nbytes;
 	char *data_buf;
-	bool writethrough = false;
+	bool writethrough = false, is_rdma_channel = false;
 	int err = 0;
+	unsigned int max_write_size = work->conn->vals->max_write_size;
 
 	WORK_BUFFERS(work, req, rsp);
 
@@ -6431,8 +6438,17 @@ int smb2_write(struct ksmbd_work *work)
 		return smb2_write_pipe(work);
 	}
 
+	offset = le64_to_cpu(req->Offset);
+	length = le32_to_cpu(req->Length);
+
 	if (req->Channel == SMB2_CHANNEL_RDMA_V1 ||
 	    req->Channel == SMB2_CHANNEL_RDMA_V1_INVALIDATE) {
+		is_rdma_channel = true;
+		max_write_size = get_smbd_max_read_write_size();
+		length = le32_to_cpu(req->RemainingBytes);
+	}
+
+	if (is_rdma_channel == true) {
 		unsigned int ch_offset = le16_to_cpu(req->WriteChannelInfoOffset);
 
 		if (req->Length != 0 || req->DataOffset != 0 ||
@@ -6467,12 +6483,9 @@ int smb2_write(struct ksmbd_work *work)
 		goto out;
 	}
 
-	offset = le64_to_cpu(req->Offset);
-	length = le32_to_cpu(req->Length);
-
-	if (length > work->conn->vals->max_write_size) {
+	if (length > max_write_size) {
 		ksmbd_debug(SMB, "limiting write size to max size(%u)\n",
-			    work->conn->vals->max_write_size);
+			    max_write_size);
 		err = -EINVAL;
 		goto out;
 	}
@@ -6480,8 +6493,7 @@ int smb2_write(struct ksmbd_work *work)
 	if (le32_to_cpu(req->Flags) & SMB2_WRITEFLAG_WRITE_THROUGH)
 		writethrough = true;
 
-	if (req->Channel != SMB2_CHANNEL_RDMA_V1 &&
-	    req->Channel != SMB2_CHANNEL_RDMA_V1_INVALIDATE) {
+	if (is_rdma_channel == false) {
 		if ((u64)le16_to_cpu(req->DataOffset) + length >
 		    get_rfc1002_len(work->request_buf)) {
 			pr_err("invalid write data offset %u, smb_len %u\n",
@@ -6507,8 +6519,7 @@ int smb2_write(struct ksmbd_work *work)
 		/* read data from the client using rdma channel, and
 		 * write the data.
 		 */
-		nbytes = smb2_write_rdma_channel(work, req, fp, offset,
-						 le32_to_cpu(req->RemainingBytes),
+		nbytes = smb2_write_rdma_channel(work, req, fp, offset, length,
 						 writethrough);
 		if (nbytes < 0) {
 			err = (int)nbytes;

fs/ksmbd/transport_rdma.c

@@ -220,6 +220,11 @@ void init_smbd_max_io_size(unsigned int sz)
 	smb_direct_max_read_write_size = sz;
 }
 
+unsigned int get_smbd_max_read_write_size(void)
+{
+	return smb_direct_max_read_write_size;
+}
+
 static inline int get_buf_page_count(void *buf, int size)
 {
 	return DIV_ROUND_UP((uintptr_t)buf + size, PAGE_SIZE) -

fs/ksmbd/transport_rdma.h

@@ -57,11 +57,13 @@ int ksmbd_rdma_init(void);
 void ksmbd_rdma_destroy(void);
 bool ksmbd_rdma_capable_netdev(struct net_device *netdev);
 void init_smbd_max_io_size(unsigned int sz);
+unsigned int get_smbd_max_read_write_size(void);
 #else
 static inline int ksmbd_rdma_init(void) { return 0; }
 static inline int ksmbd_rdma_destroy(void) { return 0; }
 static inline bool ksmbd_rdma_capable_netdev(struct net_device *netdev) { return false; }
 static inline void init_smbd_max_io_size(unsigned int sz) { }
+static inline unsigned int get_smbd_max_read_write_size(void) { return 0; }
 #endif
 
 #endif /* __KSMBD_TRANSPORT_RDMA_H__ */