2 * Copyright (c) 1992, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software donated to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94
38 * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
39 * $FreeBSD: src/sys/miscfs/nullfs/null_vfsops.c,v 1.35.2.3 2001/07/26 20:37:11 iedowse Exp $
40 * $DragonFly: src/sys/vfs/nullfs/null_vfsops.c,v 1.28 2006/10/10 17:16:48 dillon Exp $
45 * (See null_vnops.c for a description of what this does.)
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/vnode.h>
54 #include <sys/mount.h>
55 #include <sys/nlookup.h>
58 extern struct vop_ops null_vnode_vops;
60 static MALLOC_DEFINE(M_NULLFSMNT, "NULLFS mount", "NULLFS mount structure");
62 static int nullfs_root(struct mount *mp, struct vnode **vpp);
63 static int nullfs_statfs(struct mount *mp, struct statfs *sbp,
70 nullfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
73 struct null_args args;
75 struct null_mount *xmp;
77 struct nlookupdata nd;
79 NULLFSDEBUG("nullfs_mount(mp = %p)\n", (void *)mp);
84 if (mp->mnt_flag & MNT_UPDATE) {
91 error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
99 error = nlookup_init(&nd, args.target, UIO_USERSPACE, NLC_FOLLOW);
101 error = nlookup(&nd);
103 error = cache_vget(nd.nl_ncp, nd.nl_cred, LK_EXCLUSIVE,
107 xmp = (struct null_mount *) kmalloc(sizeof(struct null_mount),
108 M_NULLFSMNT, M_WAITOK); /* XXX */
111 * Save reference to underlying FS
114 * As lite stacking enters the scene, the old way of doing this
115 * -- via the vnode -- is not good enough anymore...
117 xmp->nullm_vfs = nd.nl_ncp->nc_mount;
120 vfs_add_vnodeops(mp, &null_vnode_vops, &mp->mnt_vn_norm_ops);
125 * Keep a held reference to the root vnode.
126 * It is vrele'd in nullfs_unmount.
128 xmp->nullm_rootvp = rootvp;
130 * XXX What's the proper safety condition for querying
131 * the underlying mount? Is this flag tuning necessary
134 if (xmp->nullm_vfs->mnt_flag & MNT_LOCAL)
135 mp->mnt_flag |= MNT_LOCAL;
136 mp->mnt_data = (qaddr_t) xmp;
139 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
141 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
142 (void)nullfs_statfs(mp, &mp->mnt_stat, cred);
143 NULLFSDEBUG("nullfs_mount: lower %s, alias at %s\n",
144 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntfromname);
149 * Free reference to null layer
152 nullfs_unmount(struct mount *mp, int mntflags)
154 struct null_mount *xmp;
157 NULLFSDEBUG("nullfs_unmount: mp = %p\n", (void *)mp);
159 if (mntflags & MNT_FORCE)
163 * Finally, throw away the null_mount structure
165 xmp = (void *)mp->mnt_data;
167 if (xmp->nullm_rootvp) {
168 vrele(xmp->nullm_rootvp);
169 xmp->nullm_rootvp = NULL;
171 kfree(xmp, M_NULLFSMNT);
176 nullfs_root(struct mount *mp, struct vnode **vpp)
181 NULLFSDEBUG("nullfs_root(mp = %p, vp = %p)\n", (void *)mp,
182 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp);
185 * Return locked reference to root.
187 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
188 error = vget(vp, LK_EXCLUSIVE | LK_RETRY);
195 nullfs_quotactl(struct mount *mp, int cmd, uid_t uid, caddr_t arg,
198 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, cred);
202 nullfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
207 NULLFSDEBUG("nullfs_statfs(mp = %p, vp = %p)\n", (void *)mp,
208 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp);
210 bzero(&mstat, sizeof(mstat));
212 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, cred);
216 /* now copy across the "interesting" information and fake the rest */
217 sbp->f_type = mstat.f_type;
218 sbp->f_flags = mstat.f_flags;
219 sbp->f_bsize = mstat.f_bsize;
220 sbp->f_iosize = mstat.f_iosize;
221 sbp->f_blocks = mstat.f_blocks;
222 sbp->f_bfree = mstat.f_bfree;
223 sbp->f_bavail = mstat.f_bavail;
224 sbp->f_files = mstat.f_files;
225 sbp->f_ffree = mstat.f_ffree;
226 if (sbp != &mp->mnt_stat) {
227 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
228 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
234 nullfs_checkexp(struct mount *mp, struct sockaddr *nam, int *extflagsp,
235 struct ucred **credanonp)
238 return VFS_CHECKEXP(MOUNTTONULLMOUNT(mp)->nullm_vfs, nam,
239 extflagsp, credanonp);
243 nullfs_extattrctl(struct mount *mp, int cmd, const char *attrname, caddr_t arg,
246 return VFS_EXTATTRCTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, attrname,
251 static struct vfsops null_vfsops = {
252 .vfs_mount = nullfs_mount,
253 .vfs_unmount = nullfs_unmount,
254 .vfs_root = nullfs_root,
255 .vfs_quotactl = nullfs_quotactl,
256 .vfs_statfs = nullfs_statfs,
257 .vfs_sync = vfs_stdsync,
258 .vfs_checkexp = nullfs_checkexp,
259 .vfs_extattrctl = nullfs_extattrctl
262 VFS_SET(null_vfsops, null, VFCF_LOOPBACK);