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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Portions of this source code were derived from Berkeley 4.3 BSD
* under license from the Regents of the University of California.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/param.h>
#include <sys/isa_defs.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/cred.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/pathname.h>
#include <sys/vnode.h>
#include <sys/vfs.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/debug.h>
#include <fs/fs_subr.h>
/*
* Common code for pathconf(), fpathconf() system calls
*/
static long
cpathconf(register vnode_t *vp, int cmd, struct cred *cr)
{
struct statvfs64 sb;
int error;
ulong_t val;
switch (cmd) {
case _PC_2_SYMLINKS:
if (error = VOP_PATHCONF(vp, _PC_SYMLINK_MAX, &val, cr, NULL))
return ((long)set_errno(error));
return ((long)(val > 0));
case _PC_ALLOC_SIZE_MIN:
case _PC_REC_INCR_XFER_SIZE:
case _PC_REC_MAX_XFER_SIZE:
case _PC_REC_MIN_XFER_SIZE:
case _PC_REC_XFER_ALIGN:
if ((error = VFS_STATVFS(vp->v_vfsp, &sb)) != 0)
return ((long)set_errno(error));
/*
* There is generally no harm in doing larger transfers, but
* there's a point of diminishing returns. With 1MB transfers,
* even if they're random, you get very close to platter speed.
* Se we return 1MB as the maximum transfer size.
*/
if (cmd == _PC_REC_MAX_XFER_SIZE)
return ((long)MAX(sb.f_bsize, 1UL << 20));
/*
* By definition, f_frsize is the smallest filesystem block.
* However, _PC_ALLOC_SIZE_MIN is intended to define the
* threshold for direct I/O. This implies two requirements:
* the VM and I/O subsystems must be able to create mappings
* for DMA, which requires at least page alignment; and the
* filesystem must avoid read/modify/write, which generally
* requires multiples of its 'preferred' blocksize, f_bsize.
*
* PAGESIZE alignment is sufficient for DMA and block copy.
* Rounding up to the filesystem 'preferred' blocksize
* works just as well.
*
* All together, this means that the remaining parameters
* map into the same value.
*/
return ((long)MAX(sb.f_bsize, PAGESIZE));
case _PC_ASYNC_IO:
return (1l);
case _PC_PRIO_IO:
return ((long)set_errno(EINVAL));
case _PC_SYNC_IO:
if (!(error = VOP_FSYNC(vp, FSYNC, cr, NULL)))
return (1l);
return ((long)set_errno(error));
case _PC_XATTR_ENABLED:
return ((vp->v_vfsp->vfs_flag & VFS_XATTR) ? 1 : 0);
default:
if (error = VOP_PATHCONF(vp, cmd, &val, cr, NULL))
return ((long)set_errno(error));
return (val);
}
/* NOTREACHED */
}
/* fpathconf/pathconf interfaces */
long
fpathconf(int fdes, int name)
{
file_t *fp;
long retval;
if ((fp = getf(fdes)) == NULL)
return (set_errno(EBADF));
retval = cpathconf(fp->f_vnode, name, fp->f_cred);
releasef(fdes);
return (retval);
}
long
pathconf(char *fname, int name)
{
vnode_t *vp;
long retval;
int error;
int estale_retry = 0;
lookup:
if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) {
if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
goto lookup;
return ((long)set_errno(error));
}
retval = cpathconf(vp, name, CRED());
VN_RELE(vp);
return (retval);
}
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