cifs: Change SMB2_open to return an iov for the error parameter

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

fs/cifs/smb2ops.c

@@ -1451,6 +1451,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
 	struct cifs_open_parms oparms;
 	struct cifs_fid fid;
+	struct kvec err_iov = {NULL, 0};
 	struct smb2_err_rsp *err_buf = NULL;
 	struct smb2_symlink_err_rsp *symlink;
 	unsigned int sub_len;
@@ -1473,15 +1474,16 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 	oparms.fid = &fid;
 	oparms.reconnect = false;
 
-	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_buf);
+	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_iov);
 
 	if (!rc || !err_buf) {
 		kfree(utf16_path);
 		return -ENOENT;
 	}
 
+	err_buf = err_iov.iov_base;
 	if (le32_to_cpu(err_buf->ByteCount) < sizeof(struct smb2_symlink_err_rsp) ||
-	    get_rfc1002_length(err_buf) + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE) {
+	    err_iov.iov_len + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE) {
 		kfree(utf16_path);
 		return -ENOENT;
 	}
@@ -1494,13 +1496,13 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 	print_len = le16_to_cpu(symlink->PrintNameLength);
 	print_offset = le16_to_cpu(symlink->PrintNameOffset);
 
-	if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size <
+	if (err_iov.iov_len + server->vals->header_preamble_size <
 			SMB2_SYMLINK_STRUCT_SIZE + sub_offset + sub_len) {
 		kfree(utf16_path);
 		return -ENOENT;
 	}
 
-	if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size <
+	if (err_iov.iov_len + server->vals->header_preamble_size <
 			SMB2_SYMLINK_STRUCT_SIZE + print_offset + print_len) {
 		kfree(utf16_path);
 		return -ENOENT;

fs/cifs/smb2pdu.c

@@ -1807,7 +1807,7 @@ alloc_path_with_tree_prefix(__le16 **out_path, int *out_size, int *out_len,
 int
 SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 	  __u8 *oplock, struct smb2_file_all_info *buf,
-	  struct smb2_err_rsp **err_buf)
+	  struct kvec *err_iov)
 {
 	struct smb2_create_req *req;
 	struct smb2_create_rsp *rsp;
@@ -1947,9 +1947,11 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 
 	if (rc != 0) {
 		cifs_stats_fail_inc(tcon, SMB2_CREATE_HE);
-		if (err_buf && rsp)
-			*err_buf = kmemdup(rsp, get_rfc1002_length(rsp) + 4,
-					   GFP_KERNEL);
+		if (err_iov && rsp) {
+			*err_iov = rsp_iov;
+			resp_buftype = CIFS_NO_BUFFER;
+			rsp = NULL;
+		}
 		goto creat_exit;
 	}
 

fs/cifs/smb2proto.h

@@ -122,7 +122,7 @@ extern int SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon);
 extern int SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms,
 		     __le16 *path, __u8 *oplock,
 		     struct smb2_file_all_info *buf,
-		     struct smb2_err_rsp **err_buf);
+		     struct kvec *err_iov);
 extern int SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon,
 		     u64 persistent_fid, u64 volatile_fid, u32 opcode,
 		     bool is_fsctl, char *in_data, u32 indatalen,