freebsd-dev/lib/libkvm/kvm_getswapinfo.c

172 lines
3.7 KiB
C

/*
* Copyright (c) 1999, Matthew Dillon. All Rights Reserved.
* Copyright (c) 2001, Thomas Moestl
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided under the terms of the BSD
* Copyright as found in /usr/src/COPYRIGHT in the FreeBSD source tree.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/blist.h>
#include <sys/sysctl.h>
#include <vm/vm_param.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <nlist.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include "kvm_private.h"
#define NL_SWAPBLIST 0
#define NL_SWDEVT 1
#define NL_NSWDEV 2
#define NL_DMMAX 3
static int kvm_swap_nl_cached = 0;
static int unswdev; /* number of found swap dev's */
static int dmmax;
static int kvm_getswapinfo_sysctl(kvm_t *, struct kvm_swap *, int, int);
static int getsysctl(kvm_t *, char *, void *, size_t);
#define GETSWDEVNAME(dev, str, flags) \
if (dev == NODEV) { \
strlcpy(str, "[NFS swap]", sizeof(str)); \
} else { \
snprintf( \
str, sizeof(str),"%s%s", \
((flags & SWIF_DEV_PREFIX) ? _PATH_DEV : ""), \
devname(dev, S_IFCHR) \
); \
}
int
kvm_getswapinfo(
kvm_t *kd,
struct kvm_swap *swap_ary,
int swap_max,
int flags
) {
/*
* clear cache
*/
if (kd == NULL) {
kvm_swap_nl_cached = 0;
return(0);
}
if (ISALIVE(kd)) {
return kvm_getswapinfo_sysctl(kd, swap_ary, swap_max, flags);
} else {
return -1;
}
}
#define GETSYSCTL(kd, name, var) \
getsysctl(kd, name, &(var), sizeof(var))
/* The maximum MIB length for vm.swap_info and an additional device number */
#define SWI_MAXMIB 3
int
kvm_getswapinfo_sysctl(
kvm_t *kd,
struct kvm_swap *swap_ary,
int swap_max,
int flags
) {
int ti, ttl;
size_t mibi, len;
int soid[SWI_MAXMIB];
struct xswdev xsd;
struct kvm_swap tot;
if (!GETSYSCTL(kd, "vm.dmmax", dmmax))
return -1;
mibi = SWI_MAXMIB - 1;
if (sysctlnametomib("vm.swap_info", soid, &mibi) == -1) {
_kvm_err(kd, kd->program, "sysctlnametomib failed: %s",
strerror(errno));
return -1;
}
bzero(&tot, sizeof(tot));
for (unswdev = 0;; unswdev++) {
soid[mibi] = unswdev;
len = sizeof(xsd);
if (sysctl(soid, mibi + 1, &xsd, &len, NULL, 0) == -1) {
if (errno == ENOENT)
break;
_kvm_err(kd, kd->program, "cannot read sysctl: %s.",
strerror(errno));
return -1;
}
if (len != sizeof(xsd)) {
_kvm_err(kd, kd->program, "struct xswdev has unexpected "
"size; kernel and libkvm out of sync?");
return -1;
}
if (xsd.xsw_version != XSWDEV_VERSION) {
_kvm_err(kd, kd->program, "struct xswdev version "
"mismatch; kernel and libkvm out of sync?");
return -1;
}
ttl = xsd.xsw_nblks - dmmax;
if (unswdev < swap_max - 1) {
bzero(&swap_ary[unswdev], sizeof(swap_ary[unswdev]));
swap_ary[unswdev].ksw_total = ttl;
swap_ary[unswdev].ksw_used = xsd.xsw_used;
swap_ary[unswdev].ksw_flags = xsd.xsw_flags;
GETSWDEVNAME(xsd.xsw_dev, swap_ary[unswdev].ksw_devname,
flags);
}
tot.ksw_total += ttl;
tot.ksw_used += xsd.xsw_used;
}
ti = unswdev;
if (ti >= swap_max)
ti = swap_max - 1;
if (ti >= 0)
swap_ary[ti] = tot;
return(ti);
}
static int
getsysctl (
kvm_t *kd,
char *name,
void *ptr,
size_t len
) {
size_t nlen = len;
if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
_kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
strerror(errno));
return (0);
}
if (nlen != len) {
_kvm_err(kd, kd->program, "sysctl %s has unexpected size", name);
return (0);
}
return (1);
}