freebsd-skq/lib/libgeom/geom_stats.c
pfg 260ba0bff1 lib: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-26 02:00:33 +00:00

186 lines
4.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003 Poul-Henning Kamp
* 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.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* 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.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/devicestat.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libgeom.h>
/************************************************************/
static uint npages, spp;
static int pagesize, statsfd = -1;
static u_char *statp;
void
geom_stats_close(void)
{
if (statsfd == -1)
return;
munmap(statp, npages *pagesize);
statp = NULL;
close (statsfd);
statsfd = -1;
}
void
geom_stats_resync(void)
{
void *p;
if (statsfd == -1)
return;
for (;;) {
p = mmap(statp, (npages + 1) * pagesize,
PROT_READ, MAP_SHARED, statsfd, 0);
if (p == MAP_FAILED)
break;
else
statp = p;
npages++;
}
}
int
geom_stats_open(void)
{
int error;
void *p;
if (statsfd != -1)
return (EBUSY);
statsfd = open(_PATH_DEV DEVSTAT_DEVICE_NAME, O_RDONLY);
if (statsfd < 0)
return (errno);
pagesize = getpagesize();
spp = pagesize / sizeof(struct devstat);
p = mmap(NULL, pagesize, PROT_READ, MAP_SHARED, statsfd, 0);
if (p == MAP_FAILED) {
error = errno;
close(statsfd);
statsfd = -1;
errno = error;
return (error);
}
statp = p;
npages = 1;
geom_stats_resync();
return (0);
}
struct snapshot {
u_char *ptr;
uint pages;
uint pagesize;
uint perpage;
struct timespec time;
/* used by getnext: */
uint u, v;
};
void *
geom_stats_snapshot_get(void)
{
struct snapshot *sp;
sp = malloc(sizeof *sp);
if (sp == NULL)
return (NULL);
memset(sp, 0, sizeof *sp);
sp->ptr = malloc(pagesize * npages);
if (sp->ptr == NULL) {
free(sp);
return (NULL);
}
memset(sp->ptr, 0, pagesize * npages); /* page in, cache */
clock_gettime(CLOCK_REALTIME, &sp->time);
memset(sp->ptr, 0, pagesize * npages); /* page in, cache */
memcpy(sp->ptr, statp, pagesize * npages);
sp->pages = npages;
sp->perpage = spp;
sp->pagesize = pagesize;
return (sp);
}
void
geom_stats_snapshot_free(void *arg)
{
struct snapshot *sp;
sp = arg;
free(sp->ptr);
free(sp);
}
void
geom_stats_snapshot_timestamp(void *arg, struct timespec *tp)
{
struct snapshot *sp;
sp = arg;
*tp = sp->time;
}
void
geom_stats_snapshot_reset(void *arg)
{
struct snapshot *sp;
sp = arg;
sp->u = sp->v = 0;
}
struct devstat *
geom_stats_snapshot_next(void *arg)
{
struct devstat *gsp;
struct snapshot *sp;
sp = arg;
gsp = (struct devstat *)
(sp->ptr + sp->u * pagesize + sp->v * sizeof *gsp);
if (++sp->v >= sp->perpage) {
if (++sp->u >= sp->pages)
return (NULL);
else
sp->v = 0;
}
return (gsp);
}