freebsd-skq/lib/libprocstat/zfs.c
avg 63e6bff79c libprocstat: fix ZFS support
First of all, znode_phys_t hasn't been used for storing file attributes
for a long time now.  Modern ZFS versions use a System Attribute table
with a flexible layout.  But more importantly all the required
information is available in znode_t itself.

It's not easy to include zfs_znode.h in userland without breaking code
because the most interesting parts of the header are kernel-only. And
hardcoding field offsets is too fragile.  So, I created a new
compilation unit that includes zfs_znode.h using some mild kludges to
get it and its dependencies to compile in userland.  The compilation
unit exports interesting field offsets and does not have any other code.

PR:		194117
Reviewed by:	markj
MFC after:	2 weeks
Sponsored by:	Panzura
Differential Revision: https://reviews.freebsd.org/D24941
2020-05-22 11:20:23 +00:00

113 lines
3.3 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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>
#undef _KERNEL
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/vnode.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"
#include "zfs_defs.h"
int
zfs_filestat(kvm_t *kd, struct vnode *vp, struct vnstat *vn)
{
struct mount mount, *mountptr;
void *znodeptr;
char *dataptr;
size_t len;
int size;
len = sizeof(size);
if (sysctlbyname("debug.sizeof.znode", &size, &len, NULL, 0) == -1) {
warnx("error getting sysctl");
return (1);
}
dataptr = malloc(size);
if (dataptr == NULL) {
warnx("error allocating memory for znode storage");
return (1);
}
if ((size_t)size < offsetof_z_id + sizeof(uint64_t) ||
(size_t)size < offsetof_z_mode + sizeof(mode_t) ||
(size_t)size < offsetof_z_size + sizeof(uint64_t)) {
warnx("znode_t size is too small");
goto bad;
}
if ((size_t)size != sizeof_znode_t)
warnx("znode_t size mismatch, data could be wrong");
/* Since we have problems including vnode.h, we'll use the wrappers. */
znodeptr = getvnodedata(vp);
if (!kvm_read_all(kd, (unsigned long)znodeptr, dataptr,
(size_t)size)) {
warnx("can't read znode at %p", (void *)znodeptr);
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;
}
/*
* XXX Assume that this is a znode, but it can be a special node
* under .zfs/.
*/
vn->vn_fsid = mount.mnt_stat.f_fsid.val[0];
vn->vn_fileid = *(uint64_t *)(void *)(dataptr + offsetof_z_id);
vn->vn_mode = *(mode_t *)(void *)(dataptr + offsetof_z_mode);
vn->vn_size = *(uint64_t *)(void *)(dataptr + offsetof_z_size);
free(dataptr);
return (0);
bad:
free(dataptr);
return (1);
}