freebsd-dev/usr.bin/fstat/zfs.c
Andriy Gapon 497e910cd3 fstat: fix fsid comparison when executed on systems with 64-bit long
This affects only fstat on zfs and devfs, only on 64-bit systems
and only when fsid is greater than 2^31 - 1.
When fstat examines a file via stat(2) it takes uint32_t st_dev
and assigns to (signed) (64-bit) long fsid, this results in
a positive value.
When fstat examines opened files it takes int32_t f_fsid.val[0]
and assigns to (signed) (64-bit) long fsid, this results in
a negative value.
So, while initially st_dev and f_fsid.val[0] have the same bit
values they get promoted to different 64-bit values because
of the signed-vs-unsigned difference.

A fix is to use "more natural" positive numbers by introducing
intermediate unsigned cast for f_fsid.val[0].

Reviewed by:	jhb, lulf
Approved by:	re (kib)
MFC after:	1 week (to stable/7)
2009-08-20 10:57:14 +00:00

136 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 <err.h>
#include <kvm.h>
#include <stdio.h>
#include <stdlib.h>
#define ZFS
#undef dprintf
#include <fstat.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(struct vnode *vp, struct filestat *fsp)
{
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) {
dprintf(stderr, "error getting sysctl\n");
return (0);
}
znodeptr = malloc(size);
if (znodeptr == NULL) {
dprintf(stderr, "error allocating memory for znode storage\n");
return (0);
}
/* Since we have problems including vnode.h, we'll use the wrappers. */
vnodeptr = getvnodedata(vp);
if (!KVM_READ(vnodeptr, znodeptr, (size_t)size)) {
dprintf(stderr, "can't read znode at %p for pid %d\n",
(void *)vnodeptr, Pid);
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(zphys_addr, &zphys, sizeof(zphys))) {
dprintf(stderr, "can't read znode_phys at %p for pid %d\n",
zphys_addr, Pid);
goto bad;
}
/* Get the mount pointer, and read from the address. */
mountptr = getvnodemount(vp);
if (!KVM_READ(mountptr, &mount, sizeof(mount))) {
dprintf(stderr, "can't read mount at %p for pid %d\n",
(void *)mountptr, Pid);
goto bad;
}
fsp->fsid = (long)(uint32_t)mount.mnt_stat.f_fsid.val[0];
fsp->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.
*/
fsp->mode = (mode_t)zphys.zp_mode;
fsp->size = (u_long)zphys.zp_size;
fsp->rdev = (dev_t)zphys.zp_rdev;
free(znodeptr);
return (1);
bad:
free(znodeptr);
return (0);
}