zfs-builds-mm/zfs-0.8.1/module/zfs/pathname.c

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2019-07-06 23:40:11 +02:00
/*
* 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 2007 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 */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
#include <sys/types.h>
#include <sys/pathname.h>
#include <sys/kmem.h>
#include <sys/sysmacros.h>
/*
* Pathname utilities.
*
* In translating file names we copy each argument file
* name into a pathname structure where we operate on it.
* Each pathname structure can hold "pn_bufsize" characters
* including a terminating null, and operations here support
* allocating and freeing pathname structures, fetching
* strings from user space, getting the next character from
* a pathname, combining two pathnames (used in symbolic
* link processing), and peeling off the first component
* of a pathname.
*/
/*
* Allocate contents of pathname structure. Structure is typically
* an automatic variable in calling routine for convenience.
*
* May sleep in the call to kmem_alloc() and so must not be called
* from interrupt level.
*/
void
pn_alloc(struct pathname *pnp)
{
pn_alloc_sz(pnp, MAXPATHLEN);
}
void
pn_alloc_sz(struct pathname *pnp, size_t sz)
{
pnp->pn_path = pnp->pn_buf = kmem_alloc(sz, KM_SLEEP);
pnp->pn_pathlen = 0;
pnp->pn_bufsize = sz;
}
/*
* Free pathname resources.
*/
void
pn_free(struct pathname *pnp)
{
/* pn_bufsize is usually MAXPATHLEN, but may not be */
kmem_free(pnp->pn_buf, pnp->pn_bufsize);
pnp->pn_path = pnp->pn_buf = NULL;
pnp->pn_pathlen = pnp->pn_bufsize = 0;
}