70f3685105
introduce a new argument, "namespace", rather than relying on a first-
character namespace indicator. This is in line with more recent
thinking on EA interfaces on various mailing lists, including the
posix1e, Linux acl-devel, and trustedbsd-discuss forums. Two namespaces
are defined by default, EXTATTR_NAMESPACE_SYSTEM and
EXTATTR_NAMESPACE_USER, where the primary distinction lies in the
access control model: user EAs are accessible based on the normal
MAC and DAC file/directory protections, and system attributes are
limited to kernel-originated or appropriately privileged userland
requests.
o These API changes occur at several levels: the namespace argument is
introduced in the extattr_{get,set}_file() system call interfaces,
at the vnode operation level in the vop_{get,set}extattr() interfaces,
and in the UFS extended attribute implementation. Changes are also
introduced in the VFS extattrctl() interface (system call, VFS,
and UFS implementation), where the arguments are modified to include
a namespace field, as well as modified to advoid direct access to
userspace variables from below the VFS layer (in the style of recent
changes to mount by adrian@FreeBSD.org). This required some cleanup
and bug fixing regarding VFS locks and the VFS interface, as a vnode
pointer may now be optionally submitted to the VFS_EXTATTRCTL()
call. Updated documentation for the VFS interface will be committed
shortly.
o In the near future, the auto-starting feature will be updated to
search two sub-directories to the ".attribute" directory in appropriate
file systems: "user" and "system" to locate attributes intended for
those namespaces, as the single filename is no longer sufficient
to indicate what namespace the attribute is intended for. Until this
is committed, all attributes auto-started by UFS will be placed in
the EXTATTR_NAMESPACE_SYSTEM namespace.
o The default POSIX.1e attribute names for ACLs and Capabilities have
been updated to no longer include the '$' in their filename. As such,
if you're using these features, you'll need to rename the attribute
backing files to the same names without '$' symbols in front.
o Note that these changes will require changes in userland, which will
be committed shortly. These include modifications to the extended
attribute utilities, as well as to libutil for new namespace
string conversion routines. Once the matching userland changes are
committed, a buildworld is recommended to update all the necessary
include files and verify that the kernel and userland environments
are in sync. Note: If you do not use extended attributes (most people
won't), upgrading is not imperative although since the system call
API has changed, the new userland extended attribute code will no longer
compile with old include files.
o Couple of minor cleanups while I'm there: make more code compilation
conditional on FFS_EXTATTR, which should recover a bit of space on
kernels running without EA's, as well as update copyright dates.
Obtained from: TrustedBSD Project
444 lines
11 KiB
C
444 lines
11 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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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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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* @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94
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*
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* @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
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* $FreeBSD$
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*/
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/*
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* Null Layer
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* (See null_vnops.c for a description of what this does.)
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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/kernel.h>
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#include <sys/malloc.h>
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#include <sys/vnode.h>
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#include <sys/mount.h>
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#include <sys/namei.h>
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#include <miscfs/nullfs/null.h>
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static MALLOC_DEFINE(M_NULLFSMNT, "NULLFS mount", "NULLFS mount structure");
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static int nullfs_fhtovp(struct mount *mp, struct fid *fidp,
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struct vnode **vpp);
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static int nullfs_checkexp(struct mount *mp, struct sockaddr *nam,
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int *extflagsp, struct ucred **credanonp);
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static int nullfs_mount(struct mount *mp, char *path, caddr_t data,
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struct nameidata *ndp, struct proc *p);
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static int nullfs_quotactl(struct mount *mp, int cmd, uid_t uid,
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caddr_t arg, struct proc *p);
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static int nullfs_root(struct mount *mp, struct vnode **vpp);
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static int nullfs_start(struct mount *mp, int flags, struct proc *p);
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static int nullfs_statfs(struct mount *mp, struct statfs *sbp,
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struct proc *p);
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static int nullfs_sync(struct mount *mp, int waitfor,
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struct ucred *cred, struct proc *p);
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static int nullfs_unmount(struct mount *mp, int mntflags, struct proc *p);
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static int nullfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp);
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static int nullfs_vptofh(struct vnode *vp, struct fid *fhp);
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static int nullfs_extattrctl(struct mount *mp, int cmd,
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struct vnode *filename_vp,
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int namespace, const char *attrname,
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struct proc *p);
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/*
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* Mount null layer
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*/
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static int
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nullfs_mount(mp, path, data, ndp, p)
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struct mount *mp;
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char *path;
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caddr_t data;
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struct nameidata *ndp;
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struct proc *p;
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{
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int error = 0;
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struct null_args args;
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struct vnode *lowerrootvp, *vp;
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struct vnode *nullm_rootvp;
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struct null_mount *xmp;
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u_int size;
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int isvnunlocked = 0;
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NULLFSDEBUG("nullfs_mount(mp = %p)\n", (void *)mp);
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/*
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* Update is a no-op
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*/
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if (mp->mnt_flag & MNT_UPDATE) {
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return (EOPNOTSUPP);
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/* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
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}
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/*
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* Get argument
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*/
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error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
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if (error)
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return (error);
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/*
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* Unlock lower node to avoid deadlock.
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* (XXX) VOP_ISLOCKED is needed?
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*/
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if ((mp->mnt_vnodecovered->v_op == null_vnodeop_p) &&
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VOP_ISLOCKED(mp->mnt_vnodecovered, NULL)) {
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VOP_UNLOCK(mp->mnt_vnodecovered, 0, p);
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isvnunlocked = 1;
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}
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/*
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* Find lower node
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*/
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NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
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UIO_USERSPACE, args.target, p);
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error = namei(ndp);
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/*
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* Re-lock vnode.
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*/
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if (isvnunlocked && !VOP_ISLOCKED(mp->mnt_vnodecovered, NULL))
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vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY, p);
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if (error)
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return (error);
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NDFREE(ndp, NDF_ONLY_PNBUF);
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/*
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* Sanity check on lower vnode
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*/
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lowerrootvp = ndp->ni_vp;
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vrele(ndp->ni_dvp);
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ndp->ni_dvp = NULLVP;
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/*
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* Check multi null mount to avoid `lock against myself' panic.
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*/
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if (lowerrootvp == VTONULL(mp->mnt_vnodecovered)->null_lowervp) {
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NULLFSDEBUG("nullfs_mount: multi null mount?\n");
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vput(lowerrootvp);
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return (EDEADLK);
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}
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xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
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M_NULLFSMNT, M_WAITOK); /* XXX */
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/*
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* Save reference to underlying FS
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*/
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xmp->nullm_vfs = lowerrootvp->v_mount;
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/*
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* Save reference. Each mount also holds
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* a reference on the root vnode.
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*/
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error = null_node_create(mp, lowerrootvp, &vp);
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/*
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* Unlock the node (either the lower or the alias)
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*/
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VOP_UNLOCK(vp, 0, p);
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/*
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* Make sure the node alias worked
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*/
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if (error) {
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vrele(lowerrootvp);
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free(xmp, M_NULLFSMNT); /* XXX */
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return (error);
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}
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/*
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* Keep a held reference to the root vnode.
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* It is vrele'd in nullfs_unmount.
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*/
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nullm_rootvp = vp;
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nullm_rootvp->v_flag |= VROOT;
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xmp->nullm_rootvp = nullm_rootvp;
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if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
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mp->mnt_flag |= MNT_LOCAL;
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mp->mnt_data = (qaddr_t) xmp;
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vfs_getnewfsid(mp);
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(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
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&size);
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bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
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(void)nullfs_statfs(mp, &mp->mnt_stat, p);
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NULLFSDEBUG("nullfs_mount: lower %s, alias at %s\n",
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mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
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return (0);
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}
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/*
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* VFS start. Nothing needed here - the start routine
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* on the underlying filesystem will have been called
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* when that filesystem was mounted.
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*/
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static int
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nullfs_start(mp, flags, p)
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struct mount *mp;
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int flags;
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struct proc *p;
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{
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return (0);
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/* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
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}
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/*
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* Free reference to null layer
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*/
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static int
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nullfs_unmount(mp, mntflags, p)
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struct mount *mp;
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int mntflags;
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struct proc *p;
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{
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struct vnode *vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
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void *mntdata;
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int error;
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int flags = 0;
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NULLFSDEBUG("nullfs_unmount: mp = %p\n", (void *)mp);
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if (mntflags & MNT_FORCE)
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flags |= FORCECLOSE;
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error = VFS_ROOT(mp, &vp);
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if (error)
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return (error);
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if (vp->v_usecount > 2) {
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NULLFSDEBUG("nullfs_unmount: rootvp is busy(%d)\n",
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vp->v_usecount);
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vput(vp);
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return (EBUSY);
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}
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error = vflush(mp, vp, flags);
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if (error)
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return (error);
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#ifdef NULLFS_DEBUG
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vprint("alias root of lower", vp);
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#endif
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vput(vp);
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/*
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* Release reference on underlying root vnode
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*/
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vrele(vp);
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/*
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* And blow it away for future re-use
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*/
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vgone(vp);
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/*
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* Finally, throw away the null_mount structure
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*/
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mntdata = mp->mnt_data;
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mp->mnt_data = 0;
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free(mntdata, M_NULLFSMNT);
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return 0;
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}
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static int
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nullfs_root(mp, vpp)
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struct mount *mp;
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struct vnode **vpp;
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{
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struct proc *p = curproc; /* XXX */
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struct vnode *vp;
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NULLFSDEBUG("nullfs_root(mp = %p, vp = %p->%p)\n", (void *)mp,
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(void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp,
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(void *)NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
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/*
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* Return locked reference to root.
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*/
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vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
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VREF(vp);
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#ifdef NULLFS_DEBUG
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if (VOP_ISLOCKED(vp, NULL)) {
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Debugger("root vnode is locked.\n");
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vrele(vp);
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return (EDEADLK);
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}
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#endif
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
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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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nullfs_quotactl(mp, cmd, uid, arg, p)
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struct mount *mp;
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int cmd;
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uid_t uid;
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caddr_t arg;
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struct proc *p;
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{
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return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
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}
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static int
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nullfs_statfs(mp, sbp, p)
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struct mount *mp;
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struct statfs *sbp;
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struct proc *p;
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{
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int error;
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struct statfs mstat;
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NULLFSDEBUG("nullfs_statfs(mp = %p, vp = %p->%p)\n", (void *)mp,
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(void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp,
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(void *)NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
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bzero(&mstat, sizeof(mstat));
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error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
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if (error)
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return (error);
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/* now copy across the "interesting" information and fake the rest */
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sbp->f_type = mstat.f_type;
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sbp->f_flags = mstat.f_flags;
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sbp->f_bsize = mstat.f_bsize;
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sbp->f_iosize = mstat.f_iosize;
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sbp->f_blocks = mstat.f_blocks;
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sbp->f_bfree = mstat.f_bfree;
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sbp->f_bavail = mstat.f_bavail;
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sbp->f_files = mstat.f_files;
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sbp->f_ffree = mstat.f_ffree;
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if (sbp != &mp->mnt_stat) {
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bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
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bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
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bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
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}
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return (0);
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}
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static int
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nullfs_sync(mp, waitfor, cred, p)
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struct mount *mp;
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int waitfor;
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struct ucred *cred;
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struct proc *p;
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{
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/*
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* XXX - Assumes no data cached at null layer.
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*/
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return (0);
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}
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static int
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nullfs_vget(mp, ino, vpp)
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struct mount *mp;
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ino_t ino;
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struct vnode **vpp;
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{
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int error;
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error = VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
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if (error)
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return (error);
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return (null_node_create(mp, *vpp, vpp));
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}
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static int
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nullfs_fhtovp(mp, fidp, vpp)
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struct mount *mp;
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struct fid *fidp;
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struct vnode **vpp;
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{
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int error;
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error = VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, vpp);
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if (error)
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return (error);
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return (null_node_create(mp, *vpp, vpp));
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}
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static int
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nullfs_checkexp(mp, nam, extflagsp, credanonp)
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struct mount *mp;
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struct sockaddr *nam;
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int *extflagsp;
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struct ucred **credanonp;
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{
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return VFS_CHECKEXP(MOUNTTONULLMOUNT(mp)->nullm_vfs, nam,
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extflagsp, credanonp);
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}
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static int
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nullfs_vptofh(vp, fhp)
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struct vnode *vp;
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struct fid *fhp;
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{
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return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
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}
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static int
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nullfs_extattrctl(mp, cmd, filename_vp, namespace, attrname, p)
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struct mount *mp;
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int cmd;
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struct vnode *filename_vp;
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int namespace;
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const char *attrname;
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struct proc *p;
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{
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return VFS_EXTATTRCTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, filename_vp,
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namespace, attrname, p);
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}
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static struct vfsops null_vfsops = {
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nullfs_mount,
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nullfs_start,
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nullfs_unmount,
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nullfs_root,
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nullfs_quotactl,
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nullfs_statfs,
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nullfs_sync,
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nullfs_vget,
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nullfs_fhtovp,
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nullfs_checkexp,
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nullfs_vptofh,
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nullfs_init,
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nullfs_uninit,
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nullfs_extattrctl,
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};
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VFS_SET(null_vfsops, nullfs, VFCF_LOOPBACK);
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