freebsd-dev/lib/libprocstat/zfs.c
Stanislav Sedov 0daf62d9f5 - Commit work from libprocstat project. These patches add support for runtime
file and processes information retrieval from the running kernel via sysctl
  in the form of new library, libprocstat.  The library also supports KVM backend
  for analyzing memory crash dumps.  Both procstat(1) and fstat(1) utilities have
  been modified to take advantage of the library (as the bonus point the fstat(1)
  utility no longer need superuser privileges to operate), and the procstat(1)
  utility is now able to display information from memory dumps as well.

  The newly introduced fuser(1) utility also uses this library and able to operate
  via sysctl and kvm backends.

  The library is by no means complete (e.g. KVM backend is missing vnode name
  resolution routines, and there're no manpages for the library itself) so I
  plan to improve it further.  I'm commiting it so it will get wider exposure
  and review.

  We won't be able to MFC this work as it relies on changes in HEAD, which
  was introduced some time ago, that break kernel ABI.  OTOH we may be able
  to merge the library with KVM backend if we really need it there.

Discussed with:	rwatson
2011-05-12 10:11:39 +00:00

135 lines
3.9 KiB
C

/*-
* Copyright (c) 2007 Ulf Lilleengen
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#define _KERNEL
#include <sys/mount.h>
#include <sys/taskqueue.h>
#undef _KERNEL
#include <sys/sysctl.h>
#undef lbolt
#undef lbolt64
#undef gethrestime_sec
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/dmu.h>
#include <sys/zap.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_sa.h>
#include <netinet/in.h>
#include <err.h>
#include <kvm.h>
#include <stdio.h>
#include <stdlib.h>
#define ZFS
#include "libprocstat.h"
#include "common_kvm.h"
/*
* Offset calculations that are used to get data from znode without having the
* definition.
*/
#define LOCATION_ZID (2 * sizeof(void *))
#define LOCATION_ZPHYS(zsize) ((zsize) - (2 * sizeof(void *) + sizeof(struct task)))
int
zfs_filestat(kvm_t *kd, struct vnode *vp, struct vnstat *vn)
{
znode_phys_t zphys;
struct mount mount, *mountptr;
uint64_t *zid;
void *znodeptr, *vnodeptr;
char *dataptr;
void *zphys_addr;
size_t len;
int size;
len = sizeof(size);
if (sysctlbyname("debug.sizeof.znode", &size, &len, NULL, 0) == -1) {
warnx("error getting sysctl");
return (1);
}
znodeptr = malloc(size);
if (znodeptr == NULL) {
warnx("error allocating memory for znode storage");
return (1);
}
/* Since we have problems including vnode.h, we'll use the wrappers. */
vnodeptr = getvnodedata(vp);
if (!kvm_read_all(kd, (unsigned long)vnodeptr, znodeptr,
(size_t)size)) {
warnx("can't read znode at %p", (void *)vnodeptr);
goto bad;
}
/*
* z_id field is stored in the third pointer. We therefore skip the two
* first bytes.
*
* Pointer to the z_phys structure is the next last pointer. Therefore
* go back two bytes from the end.
*/
dataptr = znodeptr;
zid = (uint64_t *)(dataptr + LOCATION_ZID);
zphys_addr = *(void **)(dataptr + LOCATION_ZPHYS(size));
if (!kvm_read_all(kd, (unsigned long)zphys_addr, &zphys,
sizeof(zphys))) {
warnx("can't read znode_phys at %p", zphys_addr);
goto bad;
}
/* Get the mount pointer, and read from the address. */
mountptr = getvnodemount(vp);
if (!kvm_read_all(kd, (unsigned long)mountptr, &mount, sizeof(mount))) {
warnx("can't read mount at %p", (void *)mountptr);
goto bad;
}
vn->vn_fsid = mount.mnt_stat.f_fsid.val[0];
vn->vn_fileid = *zid;
/*
* XXX: Shows up wrong in output, but UFS has this error too. Could
* be that we're casting mode-variables from 64-bit to 8-bit or simply
* error in the mode-to-string function.
*/
vn->vn_mode = (mode_t)zphys.zp_mode;
vn->vn_size = (u_long)zphys.zp_size;
free(znodeptr);
return (0);
bad:
free(znodeptr);
return (1);
}