zero.c File Reference

/dev/zero (character device 1, 5): reading it gives as many zero bytes as asked for, and what is written to it is thrown away. More...

#include <core/system.h>
#include <dev/dev.h>
#include <fs/posix.h>
#include <aquila/errno.h>
#include <memdev.h>

Go to the source code of this file.

Functions
static ssize_t	zerodev_read (struct devid *dd, off_t offset, struct iobuf *io)
	Fills the reader's buffer with zeros.
static ssize_t	zerodev_write (struct devid *dd, off_t offset, struct iobuf *io)
	Takes all that is written, and throws it away.

Variables
struct dev	zerodev

Detailed Description

/dev/zero (character device 1, 5): reading it gives as many zero bytes as asked for, and what is written to it is thrown away.

Definition in file zero.c.

Function Documentation

zerodev_read()

ssize_t zerodev_read ( struct devid * dd, off_t offset, struct iobuf * io )

static

Fills the reader's buffer with zeros.

Definition at line 16 of file zero.c.

References iobuf_zero(), iobuf::resid, and zerodev_read().

Referenced by zerodev_read().

zerodev_write()

ssize_t zerodev_write ( struct devid * dd, off_t offset, struct iobuf * io )

static

Takes all that is written, and throws it away.

Definition at line 22 of file zero.c.

References iobuf_skip(), iobuf::resid, and zerodev_write().

Referenced by zerodev_write().

Variable Documentation

zerodev

struct dev zerodev

Initial value:

         = {
    .read  = zerodev_read,
    .write = zerodev_write,
 
    .fops  = {
        .open  = posix_file_open,
        .read  = posix_file_read,
        .write = posix_file_write,
        .close = posix_file_close,
 
        .can_read  = __vfs_can_always,
        .can_write = __vfs_can_always,
        .eof       = __vfs_eof_never,
    },
}

Definition at line 13 of file zero.c.

Referenced by memdev_mux().