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-rw-r--r--sys/fs/nullfs/null_vfsops.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c
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+++ b/sys/fs/nullfs/null_vfsops.c
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+/*
+ * 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.
+ *
+ * @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94
+ *
+ * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
+ * $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $
+ */
+
+/*
+ * Null Layer
+ * (See null_vnops.c for a description of what this does.)
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <miscfs/nullfs/null.h>
+
+/*
+ * Mount null layer
+ */
+int
+nullfs_mount(mp, path, data, ndp, p)
+ struct mount *mp;
+ 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;
+ u_int size;
+
+#ifdef NULLFS_DIAGNOSTIC
+ printf("nullfs_mount(mp = %x)\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
+ */
+ if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args)))
+ return (error);
+
+ /*
+ * Find lower node
+ */
+ NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
+ UIO_USERSPACE, args.target, p);
+ if (error = namei(ndp))
+ return (error);
+
+ /*
+ * Sanity check on lower vnode
+ */
+ lowerrootvp = ndp->ni_vp;
+
+ vrele(ndp->ni_dvp);
+ ndp->ni_dvp = NULL;
+
+ 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);
+ /*
+ * Unlock the node (either the lower or the alias)
+ */
+ VOP_UNLOCK(vp);
+ /*
+ * 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;
+ getnewfsid(mp, MOUNT_LOFS);
+
+ (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;
+ extern int doforce;
+
+#ifdef NULLFS_DIAGNOSTIC
+ printf("nullfs_unmount(mp = %x)\n", mp);
+#endif
+
+ if (mntflags & MNT_FORCE) {
+ /* lofs can never be rootfs so don't check for it */
+ if (!doforce)
+ return (EINVAL);
+ 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))
+ 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;
+
+#ifdef NULLFS_DIAGNOSTIC
+ printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
+ MOUNTTONULLMOUNT(mp)->nullm_rootvp,
+ NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
+ );
+#endif
+
+ /*
+ * Return locked reference to root.
+ */
+ vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
+ VREF(vp);
+ VOP_LOCK(vp);
+ *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 = %x, vp = %x->%x)\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_type = mstat.f_type;
+ 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);
+ }
+ 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, nam, vpp, exflagsp, credanonp)
+ struct mount *mp;
+ struct fid *fidp;
+ struct mbuf *nam;
+ struct vnode **vpp;
+ int *exflagsp;
+ struct ucred**credanonp;
+{
+
+ return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp);
+}
+
+int
+nullfs_vptofh(vp, fhp)
+ struct vnode *vp;
+ struct fid *fhp;
+{
+ return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
+}
+
+int nullfs_init __P((void));
+
+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,
+};
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