5da56ddb21
This eliminates a race where MNT_UPDATE flag could be lost when nmount() raced against sync(), sync_fsync() or quotactl().
252 lines
6.3 KiB
C
252 lines
6.3 KiB
C
/*-
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* Copyright (c) 1992, 1993, 1995
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software donated to Berkeley by
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* Jan-Simon Pendry.
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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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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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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* @(#)portal_vfsops.c 8.11 (Berkeley) 5/14/95
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*
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* $FreeBSD$
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*/
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/*
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* Portal Filesystem
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/domain.h>
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#include <sys/filedesc.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/malloc.h>
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#include <sys/file.h> /* Must come after sys/malloc.h */
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#include <sys/mount.h>
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#include <sys/proc.h>
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#include <sys/protosw.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/vnode.h>
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#include <fs/portalfs/portal.h>
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static MALLOC_DEFINE(M_PORTALFSMNT, "portal_mount", "PORTAL mount structure");
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static vfs_unmount_t portal_unmount;
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static vfs_root_t portal_root;
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static vfs_statfs_t portal_statfs;
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static const char *portal_opts[] = {
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"socket", "config",
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NULL
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};
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static int
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portal_cmount(struct mntarg *ma, void *data, int flags, struct thread *td)
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{
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struct portal_args args;
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int error;
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if (data == NULL)
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return (EINVAL);
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error = copyin(data, &args, sizeof args);
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if (error)
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return (error);
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ma = mount_argf(ma, "socket", "%d", args.pa_socket);
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ma = mount_argsu(ma, "config", args.pa_config, MAXPATHLEN);
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error = kernel_mount(ma, flags);
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return (error);
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}
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/*
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* Mount the per-process file descriptors (/dev/fd)
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*/
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static int
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portal_mount(struct mount *mp, struct thread *td)
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{
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struct file *fp;
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struct portalmount *fmp;
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struct socket *so;
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struct vnode *rvp;
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struct portalnode *pn;
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int error, v;
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char *p;
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if (vfs_filteropt(mp->mnt_optnew, portal_opts))
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return (EINVAL);
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error = vfs_scanopt(mp->mnt_optnew, "socket", "%d", &v);
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if (error != 1)
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return (EINVAL);
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error = vfs_getopt(mp->mnt_optnew, "config", (void **)&p, NULL);
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if (error)
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return (error);
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if ((error = fget(td, v, &fp)) != 0)
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return (error);
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if (fp->f_type != DTYPE_SOCKET) {
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fdrop(fp, td);
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return(ENOTSOCK);
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}
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so = fp->f_data; /* XXX race against userland */
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if (so->so_proto->pr_domain->dom_family != AF_UNIX) {
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fdrop(fp, td);
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return (ESOCKTNOSUPPORT);
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}
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MALLOC(pn, struct portalnode *, sizeof(struct portalnode),
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M_TEMP, M_WAITOK);
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MALLOC(fmp, struct portalmount *, sizeof(struct portalmount),
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M_PORTALFSMNT, M_WAITOK); /* XXX */
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error = getnewvnode("portal", mp, &portal_vnodeops, &rvp); /* XXX */
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if (error) {
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FREE(fmp, M_PORTALFSMNT);
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FREE(pn, M_TEMP);
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fdrop(fp, td);
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return (error);
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}
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rvp->v_data = pn;
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rvp->v_type = VDIR;
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rvp->v_vflag |= VV_ROOT;
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VTOPORTAL(rvp)->pt_arg = 0;
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VTOPORTAL(rvp)->pt_size = 0;
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VTOPORTAL(rvp)->pt_fileid = PORTAL_ROOTFILEID;
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fmp->pm_root = rvp;
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fhold(fp);
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fmp->pm_server = fp;
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MNT_ILOCK(mp);
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mp->mnt_flag |= MNT_LOCAL;
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MNT_IUNLOCK(mp);
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mp->mnt_data = (qaddr_t) fmp;
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vfs_getnewfsid(mp);
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vfs_mountedfrom(mp, p);
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fdrop(fp, td);
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return (0);
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}
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static int
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portal_unmount(mp, mntflags, td)
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struct mount *mp;
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int mntflags;
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struct thread *td;
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{
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int error, flags = 0;
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if (mntflags & MNT_FORCE)
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flags |= FORCECLOSE;
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/*
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* Clear out buffer cache. I don't think we
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* ever get anything cached at this level at the
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* moment, but who knows...
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*/
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#ifdef notyet
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mntflushbuf(mp, 0);
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if (mntinvalbuf(mp, 1))
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return (EBUSY);
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#endif
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/* There is 1 extra root vnode reference (pm_root). */
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error = vflush(mp, 1, flags, td);
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if (error)
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return (error);
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/*
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* Shutdown the socket. This will cause the select in the
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* daemon to wake up, and then the accept will get ECONNABORTED
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* which it interprets as a request to go and bury itself.
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*/
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soshutdown(VFSTOPORTAL(mp)->pm_server->f_data, 2);
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/*
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* Discard reference to underlying file. Must call closef because
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* this may be the last reference.
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*/
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closef(VFSTOPORTAL(mp)->pm_server, (struct thread *) 0);
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/*
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* Finally, throw away the portalmount structure
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*/
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free(mp->mnt_data, M_PORTALFSMNT); /* XXX */
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mp->mnt_data = 0;
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return (0);
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}
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static int
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portal_root(mp, flags, vpp, td)
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struct mount *mp;
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int flags;
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struct vnode **vpp;
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struct thread *td;
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{
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struct vnode *vp;
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/*
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* Return locked reference to root.
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*/
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vp = VFSTOPORTAL(mp)->pm_root;
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VREF(vp);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
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*vpp = vp;
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return (0);
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}
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static int
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portal_statfs(mp, sbp, td)
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struct mount *mp;
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struct statfs *sbp;
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struct thread *td;
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{
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sbp->f_flags = 0;
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sbp->f_bsize = DEV_BSIZE;
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sbp->f_iosize = DEV_BSIZE;
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sbp->f_blocks = 2; /* 1K to keep df happy */
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sbp->f_bfree = 0;
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sbp->f_bavail = 0;
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sbp->f_files = 1; /* Allow for "." */
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sbp->f_ffree = 0; /* See comments above */
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return (0);
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}
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static struct vfsops portal_vfsops = {
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.vfs_cmount = portal_cmount,
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.vfs_mount = portal_mount,
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.vfs_root = portal_root,
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.vfs_statfs = portal_statfs,
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.vfs_unmount = portal_unmount,
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};
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VFS_SET(portal_vfsops, portalfs, VFCF_SYNTHETIC);
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