linux-master/fs/read_write.c

1413 				    struct file *file_out, loff_t pos_out,
1417 	struct inode *inode_out = file_inode(file_out);
1422 	ret = generic_file_rw_checks(file_in, file_out);
1438 	} else if (file_out->f_op->copy_file_range) {
1440 		    file_out->f_op->copy_file_range)
1442 	} else if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) {
1464 	ret = generic_write_check_limits(file_out, pos_out, &count);
1484 			    struct file *file_out, loff_t pos_out,
1489 	bool samesb = file_inode(file_in)->i_sb == file_inode(file_out)->i_sb;
1494 	ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
1503 	ret = rw_verify_area(WRITE, file_out, &pos_out, len);
1510 	file_start_write(file_out);
1517 	if (!splice && file_out->f_op->copy_file_range) {
1518 		ret = file_out->f_op->copy_file_range(file_in, pos_in,
1519 						      file_out, pos_out,
1523 				file_out, pos_out,
1534 	file_end_write(file_out);
1558 	ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
1564 		fsnotify_modify(file_out);
1718  * from @file_in to @file_out.
1720 int generic_file_rw_checks(struct file *file_in, struct file *file_out)
1723 	struct inode *inode_out = file_inode(file_out);
1732 	    !(file_out->f_mode & FMODE_WRITE) ||
1733 	    (file_out->f_flags & O_APPEND))