freebsd-skq/sys/dev/lindev/full.c
bz 4c721eede8 lindev(4) [1] is supposed to be a collection of linux-specific pseudo
devices that we also support, just not by default (thus only LINT or
module builds by default).

While currently there is only "/dev/full" [2], we are planning to see more
in the future.  We may decide to change the module/dependency logic in the
future should the list grow too long.

This is not part of linux.ko as also non-linux binaries like kFreeBSD
userland or ports can make use of this as well.

Suggested by:	rwatson [1] (name)
Submitted by:	ed [2]
Discussed with:	markm, ed, rwatson, kib (weeks ago)
Reviewed by:	rwatson, brueffer (prev. version)
PR:		kern/68961
MFC after:	6 weeks
2009-09-26 12:45:28 +00:00

104 lines
2.7 KiB
C

/*-
* Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <dev/lindev/lindev.h>
static struct cdev *full_dev;
static d_read_t full_read;
static d_write_t full_write;
static struct cdevsw full_cdevsw = {
.d_version = D_VERSION,
.d_read = full_read,
.d_write = full_write,
.d_name = "full",
};
static void *zbuf;
/* ARGSUSED */
static int
full_read(struct cdev *dev __unused, struct uio *uio, int flags __unused)
{
int error = 0;
while (uio->uio_resid > 0 && error == 0)
error = uiomove(zbuf, MIN(uio->uio_resid, PAGE_SIZE), uio);
return (error);
}
/* ARGSUSED */
static int
full_write(struct cdev *dev __unused, struct uio *uio __unused,
int flags __unused)
{
return (ENOSPC);
}
/* ARGSUSED */
int
lindev_modevent_full(module_t mod __unused, int type, void *data __unused)
{
switch(type) {
case MOD_LOAD:
zbuf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK | M_ZERO);
full_dev = make_dev(&full_cdevsw, 0, UID_ROOT, GID_WHEEL,
0666, "full");
if (bootverbose)
printf("full: <full device>\n");
break;
case MOD_UNLOAD:
destroy_dev(full_dev);
free(zbuf, M_TEMP);
break;
case MOD_SHUTDOWN:
break;
default:
return (EOPNOTSUPP);
}
return (0);
}