suse man page for kfifo_to_user_rec

KFIFO_TO_USER_REC(9)						    FIFO Buffer 					      KFIFO_TO_USER_REC(9)

NAME
       kfifo_to_user_rec - gets data from the FIFO and write it to user space

SYNOPSIS
       __must_check unsigned int kfifo_to_user_rec(struct kfifo * fifo, void __user * to, unsigned int n, unsigned int recsize,
						   unsigned int * total);

ARGUMENTS
       fifo
	   the fifo to be used.

       to
	   where the data must be copied.

       n
	   the size of the destination buffer.

       recsize
	   size of record field

       total
	   pointer where the total number of to copied bytes should stored

DESCRIPTION
       This function copies at most n bytes from the FIFO to the to. In case of an error, the function returns the number of bytes which cannot be
       copied. If the returned value is equal or less the n value, the copy_to_user functions has failed. Otherwise the record doesn't fit into
       the to buffer.

       Note that with only one concurrent reader and one concurrent writer, you don't need extra locking to use these functions.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						      KFIFO_TO_USER_REC(9)