diff options
Diffstat (limited to 'lib/libkvm/kvm_getswapinfo.c')
-rw-r--r-- | lib/libkvm/kvm_getswapinfo.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/lib/libkvm/kvm_getswapinfo.c b/lib/libkvm/kvm_getswapinfo.c new file mode 100644 index 0000000..d79d70c --- /dev/null +++ b/lib/libkvm/kvm_getswapinfo.c @@ -0,0 +1,261 @@ +/* + * Copyright (c) 1999, Matthew Dillon. All Rights Reserved. + * Copyright (c) 2001, Thomas Moestl. 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 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 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/time.h> +#include <sys/stat.h> +#include <sys/blist.h> +#include <sys/sysctl.h> + +#include <vm/swap_pager.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" + +static struct nlist kvm_swap_nl[] = { + { .n_name = "_swtailq" }, /* list of swap devices and sizes */ + { .n_name = "_dmmax" }, /* maximum size of a swap block */ + { .n_name = NULL } +}; + +#define NL_SWTAILQ 0 +#define NL_DMMAX 1 + +static int kvm_swap_nl_cached = 0; +static int unswdev; /* number of found swap dev's */ +static int dmmax; + +static int kvm_getswapinfo_kvm(kvm_t *, struct kvm_swap *, int, int); +static int kvm_getswapinfo_sysctl(kvm_t *, struct kvm_swap *, int, int); +static int nlist_init(kvm_t *); +static int getsysctl(kvm_t *, const char *, void *, size_t); + +#define KREAD(kd, addr, obj) \ + (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) +#define KGET(idx, var) \ + KGET2(kvm_swap_nl[(idx)].n_value, var, kvm_swap_nl[(idx)].n_name) +#define KGET2(addr, var, msg) \ + if (KREAD(kd, (u_long)(addr), (var))) { \ + _kvm_err(kd, kd->program, "cannot read %s", msg); \ + return (-1); \ + } + +#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 kvm_getswapinfo_kvm(kd, swap_ary, swap_max, flags); + } +} + +int +kvm_getswapinfo_kvm(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, + int flags) +{ + int i, ttl; + TAILQ_HEAD(, swdevt) swtailq; + struct swdevt *sp, swinfo; + struct kvm_swap tot; + + if (!nlist_init(kd)) + return (-1); + + bzero(&tot, sizeof(tot)); + KGET(NL_SWTAILQ, &swtailq); + sp = TAILQ_FIRST(&swtailq); + for (i = 0; sp != NULL; i++) { + KGET2(sp, &swinfo, "swinfo"); + ttl = swinfo.sw_nblks - dmmax; + if (i < swap_max - 1) { + bzero(&swap_ary[i], sizeof(swap_ary[i])); + swap_ary[i].ksw_total = ttl; + swap_ary[i].ksw_used = swinfo.sw_used; + swap_ary[i].ksw_flags = swinfo.sw_flags; + GETSWDEVNAME(swinfo.sw_dev, swap_ary[i].ksw_devname, + flags); + } + tot.ksw_total += ttl; + tot.ksw_used += swinfo.sw_used; + sp = TAILQ_NEXT(&swinfo, sw_list); + } + + if (i >= swap_max) + i = swap_max - 1; + if (i >= 0) + swap_ary[i] = tot; + + return(i); +} + +#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 +nlist_init(kvm_t *kd) +{ + + if (kvm_swap_nl_cached) + return (1); + + if (kvm_nlist(kd, kvm_swap_nl) < 0) + return (0); + + /* Required entries */ + if (kvm_swap_nl[NL_SWTAILQ].n_value == 0) { + _kvm_err(kd, kd->program, "unable to find swtailq"); + return (0); + } + + if (kvm_swap_nl[NL_DMMAX].n_value == 0) { + _kvm_err(kd, kd->program, "unable to find dmmax"); + return (0); + } + + /* Get globals, type of swap */ + KGET(NL_DMMAX, &dmmax); + + kvm_swap_nl_cached = 1; + return (1); +} + +static int +getsysctl(kvm_t *kd, const 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); +} |