7dbda87219
... to ensure that we have a valid mountpoint during the call. Reviewed by: kib MFC after: 19 days
116 lines
3.1 KiB
C
116 lines
3.1 KiB
C
/*-
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* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/systm.h>
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#include <sys/pathname.h>
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#include <sys/vfs.h>
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#include <sys/vnode.h>
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int
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lookupname(char *dirname, enum uio_seg seg, enum symfollow follow,
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vnode_t **dirvpp, vnode_t **compvpp)
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{
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return (lookupnameat(dirname, seg, follow, dirvpp, compvpp, NULL));
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}
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int
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lookupnameat(char *dirname, enum uio_seg seg, enum symfollow follow,
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vnode_t **dirvpp, vnode_t **compvpp, vnode_t *startvp)
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{
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struct nameidata nd;
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int error, ltype;
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ASSERT(dirvpp == NULL);
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vref(startvp);
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ltype = VOP_ISLOCKED(startvp);
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VOP_UNLOCK(startvp, 0);
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NDINIT_ATVP(&nd, LOOKUP, LOCKLEAF | follow, seg, dirname,
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startvp, curthread);
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error = namei(&nd);
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*compvpp = nd.ni_vp;
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NDFREE(&nd, NDF_ONLY_PNBUF);
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vn_lock(startvp, ltype | LK_RETRY);
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return (error);
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}
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int
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traverse(vnode_t **cvpp, int lktype)
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{
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vnode_t *cvp;
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vnode_t *tvp;
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vfs_t *vfsp;
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int error;
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cvp = *cvpp;
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tvp = NULL;
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/*
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* If this vnode is mounted on, then we transparently indirect
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* to the vnode which is the root of the mounted file system.
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* Before we do this we must check that an unmount is not in
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* progress on this vnode.
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*/
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for (;;) {
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/*
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* Reached the end of the mount chain?
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*/
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vfsp = vn_mountedvfs(cvp);
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if (vfsp == NULL)
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break;
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error = vfs_busy(vfsp, 0);
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/*
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* tvp is NULL for *cvpp vnode, which we can't unlock.
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*/
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if (tvp != NULL)
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vput(cvp);
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else
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vrele(cvp);
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if (error)
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return (error);
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/*
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* The read lock must be held across the call to VFS_ROOT() to
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* prevent a concurrent unmount from destroying the vfs.
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*/
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error = VFS_ROOT(vfsp, lktype, &tvp);
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vfs_unbusy(vfsp);
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if (error != 0)
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return (error);
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cvp = tvp;
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}
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*cvpp = cvp;
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return (0);
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}
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