/* $OpenBSD: null_vfsops.c,v 1.11 2000/02/07 04:57:16 assar Exp $ */ /* $NetBSD: null_vfsops.c,v 1.11 1996/05/10 22:50:56 jtk Exp $ */ /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software donated to Berkeley by * Jan-Simon Pendry. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp * from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 * @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94 */ /* * Null Layer * (See null_vnops.c for a description of what this does.) */ #include #include #include #include #include #include #include #include #include #include int nullfs_mount __P((struct mount *, const char *, caddr_t, struct nameidata *, struct proc *)); int nullfs_start __P((struct mount *, int, struct proc *)); int nullfs_unmount __P((struct mount *, int, struct proc *)); int nullfs_root __P((struct mount *, struct vnode **)); int nullfs_quotactl __P((struct mount *, int, uid_t, caddr_t, struct proc *)); int nullfs_statfs __P((struct mount *, struct statfs *, struct proc *)); int nullfs_sync __P((struct mount *, int, struct ucred *, struct proc *)); int nullfs_vget __P((struct mount *, ino_t, struct vnode **)); int nullfs_fhtovp __P((struct mount *, struct fid *, struct vnode **)); int nullfs_vptofh __P((struct vnode *, struct fid *)); /* * Mount null layer */ int nullfs_mount(mp, path, data, ndp, p) struct mount *mp; const char *path; caddr_t data; struct nameidata *ndp; struct proc *p; { int error = 0; struct null_args args; struct vnode *lowerrootvp, *vp; struct vnode *nullm_rootvp; struct null_mount *xmp; size_t size; #ifdef NULLFS_DIAGNOSTIC printf("nullfs_mount(mp = %p)\n", mp); #endif /* * Update is a no-op */ if (mp->mnt_flag & MNT_UPDATE) { return (EOPNOTSUPP); /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/ } /* * Get argument */ error = copyin(data, (caddr_t)&args, sizeof(struct null_args)); if (error) return (error); /* * Find lower node */ NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF, UIO_USERSPACE, args.target, p); if ((error = namei(ndp)) != 0) return (error); /* * Sanity check on lower vnode */ lowerrootvp = ndp->ni_vp; vrele(ndp->ni_dvp); ndp->ni_dvp = NULL; if (lowerrootvp->v_type != VDIR) { vput(lowerrootvp); return (EINVAL); } xmp = (struct null_mount *) malloc(sizeof(struct null_mount), M_UFSMNT, M_WAITOK); /* XXX */ /* * Save reference to underlying FS */ xmp->nullm_vfs = lowerrootvp->v_mount; /* * Save reference. Each mount also holds * a reference on the root vnode. */ error = null_node_create(mp, lowerrootvp, &vp, 1); /* * Unlock the node (either the lower or the alias) */ VOP_UNLOCK(vp, 0, p); /* * Make sure the node alias worked */ if (error) { vrele(lowerrootvp); free(xmp, M_UFSMNT); /* XXX */ return (error); } /* * Keep a held reference to the root vnode. * It is vrele'd in nullfs_unmount. */ nullm_rootvp = vp; nullm_rootvp->v_flag |= VROOT; xmp->nullm_rootvp = nullm_rootvp; if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) mp->mnt_flag |= MNT_LOCAL; mp->mnt_data = (qaddr_t) xmp; vfs_getnewfsid(mp); (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size); bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); #ifdef NULLFS_DIAGNOSTIC printf("nullfs_mount: lower %s, alias at %s\n", mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); #endif return (0); } /* * VFS start. Nothing needed here - the start routine * on the underlying filesystem will have been called * when that filesystem was mounted. */ int nullfs_start(mp, flags, p) struct mount *mp; int flags; struct proc *p; { return (0); /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ } /* * Free reference to null layer */ int nullfs_unmount(mp, mntflags, p) struct mount *mp; int mntflags; struct proc *p; { struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; int error; int flags = 0; #ifdef NULLFS_DIAGNOSTIC printf("nullfs_unmount(mp = %p)\n", mp); #endif if (mntflags & MNT_FORCE) { flags |= FORCECLOSE; } /* * Clear out buffer cache. I don't think we * ever get anything cached at this level at the * moment, but who knows... */ #if 0 mntflushbuf(mp, 0); if (mntinvalbuf(mp, 1)) return (EBUSY); #endif if (nullm_rootvp->v_usecount > 1) return (EBUSY); if ((error = vflush(mp, nullm_rootvp, flags)) != 0) return (error); #ifdef NULLFS_DIAGNOSTIC vprint("alias root of lower", nullm_rootvp); #endif /* * Release reference on underlying root vnode */ vrele(nullm_rootvp); /* * And blow it away for future re-use */ vgone(nullm_rootvp); /* * Finally, throw away the null_mount structure */ free(mp->mnt_data, M_UFSMNT); /* XXX */ mp->mnt_data = 0; return 0; } int nullfs_root(mp, vpp) struct mount *mp; struct vnode **vpp; { struct vnode *vp; struct proc *p = curproc; #ifdef NULLFS_DIAGNOSTIC printf("nullfs_root(mp = %p, vp = %p->%p)\n", mp, MOUNTTONULLMOUNT(mp)->nullm_rootvp, NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) ); #endif /* * Return locked reference to root. */ vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; VREF(vp); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); *vpp = vp; return 0; } int nullfs_quotactl(mp, cmd, uid, arg, p) struct mount *mp; int cmd; uid_t uid; caddr_t arg; struct proc *p; { return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); } int nullfs_statfs(mp, sbp, p) struct mount *mp; struct statfs *sbp; struct proc *p; { int error; struct statfs mstat; #ifdef NULLFS_DIAGNOSTIC printf("nullfs_statfs(mp = %p, vp = %p->%p)\n", mp, MOUNTTONULLMOUNT(mp)->nullm_rootvp, NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) ); #endif bzero(&mstat, sizeof(mstat)); error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); if (error) return (error); /* now copy across the "interesting" information and fake the rest */ sbp->f_flags = mstat.f_flags; sbp->f_bsize = mstat.f_bsize; sbp->f_iosize = mstat.f_iosize; sbp->f_blocks = mstat.f_blocks; sbp->f_bfree = mstat.f_bfree; sbp->f_bavail = mstat.f_bavail; sbp->f_files = mstat.f_files; sbp->f_ffree = mstat.f_ffree; if (sbp != &mp->mnt_stat) { bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); } strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN); return (0); } int nullfs_sync(mp, waitfor, cred, p) struct mount *mp; int waitfor; struct ucred *cred; struct proc *p; { /* * XXX - Assumes no data cached at null layer. */ return (0); } int nullfs_vget(mp, ino, vpp) struct mount *mp; ino_t ino; struct vnode **vpp; { return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); } int nullfs_fhtovp(mp, fidp, vpp) struct mount *mp; struct fid *fidp; struct vnode **vpp; { return (EOPNOTSUPP); } int nullfs_vptofh(vp, fhp) struct vnode *vp; struct fid *fhp; { return (EOPNOTSUPP); } #define nullfs_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \ size_t, struct proc *)))eopnotsupp) #define nullfs_checkexp ((int (*) __P((struct mount *, struct mbuf *, \ int *, struct ucred **)))eopnotsupp) struct vfsops null_vfsops = { nullfs_mount, nullfs_start, nullfs_unmount, nullfs_root, nullfs_quotactl, nullfs_statfs, nullfs_sync, nullfs_vget, nullfs_fhtovp, nullfs_vptofh, nullfs_init, nullfs_sysctl, nullfs_checkexp };