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 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94
34 * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
40 * (See null_vnops.c for a description of what this does.)
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
47 #include <sys/malloc.h>
48 #include <sys/mount.h>
49 #include <sys/namei.h>
51 #include <sys/vnode.h>
53 #include <fs/nullfs/null.h>
55 static MALLOC_DEFINE(M_NULLFSMNT, "nullfs_mount", "NULLFS mount structure");
57 static vfs_fhtovp_t nullfs_fhtovp;
58 static vfs_mount_t nullfs_mount;
59 static vfs_quotactl_t nullfs_quotactl;
60 static vfs_root_t nullfs_root;
61 static vfs_sync_t nullfs_sync;
62 static vfs_statfs_t nullfs_statfs;
63 static vfs_unmount_t nullfs_unmount;
64 static vfs_vget_t nullfs_vget;
65 static vfs_extattrctl_t nullfs_extattrctl;
71 nullfs_mount(struct mount *mp, struct thread *td)
74 struct vnode *lowerrootvp, *vp;
75 struct vnode *nullm_rootvp;
76 struct null_mount *xmp;
78 int isvnunlocked = 0, len;
79 struct nameidata nd, *ndp = &nd;
81 NULLFSDEBUG("nullfs_mount(mp = %p)\n", (void *)mp);
83 if (mp->mnt_flag & MNT_ROOTFS)
88 if (mp->mnt_flag & MNT_UPDATE) {
90 * Only support update mounts for NFS export.
92 if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0))
101 error = vfs_getopt(mp->mnt_optnew, "target", (void **)&target, &len);
102 if (error || target[len - 1] != '\0')
106 * Unlock lower node to avoid deadlock.
107 * (XXX) VOP_ISLOCKED is needed?
109 if ((mp->mnt_vnodecovered->v_op == &null_vnodeops) &&
110 VOP_ISLOCKED(mp->mnt_vnodecovered, NULL)) {
111 VOP_UNLOCK(mp->mnt_vnodecovered, 0, td);
117 NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
118 UIO_SYSSPACE, target, td);
123 if (isvnunlocked && !VOP_ISLOCKED(mp->mnt_vnodecovered, NULL))
124 vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY, td);
128 NDFREE(ndp, NDF_ONLY_PNBUF);
131 * Sanity check on lower vnode
133 lowerrootvp = ndp->ni_vp;
136 * Check multi null mount to avoid `lock against myself' panic.
138 if (lowerrootvp == VTONULL(mp->mnt_vnodecovered)->null_lowervp) {
139 NULLFSDEBUG("nullfs_mount: multi null mount?\n");
144 xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
145 M_NULLFSMNT, M_WAITOK); /* XXX */
148 * Save reference to underlying FS
150 xmp->nullm_vfs = lowerrootvp->v_mount;
153 * Save reference. Each mount also holds
154 * a reference on the root vnode.
156 error = null_nodeget(mp, lowerrootvp, &vp);
158 * Make sure the node alias worked
161 VOP_UNLOCK(vp, 0, td);
163 free(xmp, M_NULLFSMNT); /* XXX */
168 * Keep a held reference to the root vnode.
169 * It is vrele'd in nullfs_unmount.
172 nullm_rootvp->v_vflag |= VV_ROOT;
173 xmp->nullm_rootvp = nullm_rootvp;
176 * Unlock the node (either the lower or the alias)
178 VOP_UNLOCK(vp, 0, td);
180 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) {
182 mp->mnt_flag |= MNT_LOCAL;
186 mp->mnt_kern_flag |= lowerrootvp->v_mount->mnt_kern_flag & MNTK_MPSAFE;
188 mp->mnt_data = (qaddr_t) xmp;
191 vfs_mountedfrom(mp, target);
193 NULLFSDEBUG("nullfs_mount: lower %s, alias at %s\n",
194 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
199 * Free reference to null layer
202 nullfs_unmount(mp, mntflags, td)
211 NULLFSDEBUG("nullfs_unmount: mp = %p\n", (void *)mp);
213 if (mntflags & MNT_FORCE)
216 /* There is 1 extra root vnode reference (nullm_rootvp). */
217 error = vflush(mp, 1, flags, td);
222 * Finally, throw away the null_mount structure
224 mntdata = mp->mnt_data;
226 free(mntdata, M_NULLFSMNT);
231 nullfs_root(mp, flags, vpp, td)
239 NULLFSDEBUG("nullfs_root(mp = %p, vp = %p->%p)\n", (void *)mp,
240 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp,
241 (void *)NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
244 * Return locked reference to root.
246 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
250 if (VOP_ISLOCKED(vp, NULL))
251 panic("root vnode is locked.\n");
253 vn_lock(vp, flags | LK_RETRY, td);
259 nullfs_quotactl(mp, cmd, uid, arg, td)
266 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, td);
270 nullfs_statfs(mp, sbp, td)
278 NULLFSDEBUG("nullfs_statfs(mp = %p, vp = %p->%p)\n", (void *)mp,
279 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp,
280 (void *)NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
282 bzero(&mstat, sizeof(mstat));
284 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, td);
288 /* now copy across the "interesting" information and fake the rest */
289 sbp->f_type = mstat.f_type;
290 sbp->f_flags = mstat.f_flags;
291 sbp->f_bsize = mstat.f_bsize;
292 sbp->f_iosize = mstat.f_iosize;
293 sbp->f_blocks = mstat.f_blocks;
294 sbp->f_bfree = mstat.f_bfree;
295 sbp->f_bavail = mstat.f_bavail;
296 sbp->f_files = mstat.f_files;
297 sbp->f_ffree = mstat.f_ffree;
302 nullfs_sync(mp, waitfor, td)
308 * XXX - Assumes no data cached at null layer.
314 nullfs_vget(mp, ino, flags, vpp)
321 error = VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, flags, vpp);
325 return (null_nodeget(mp, *vpp, vpp));
329 nullfs_fhtovp(mp, fidp, vpp)
335 error = VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, vpp);
339 return (null_nodeget(mp, *vpp, vpp));
343 nullfs_extattrctl(mp, cmd, filename_vp, namespace, attrname, td)
346 struct vnode *filename_vp;
348 const char *attrname;
351 return VFS_EXTATTRCTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, filename_vp,
352 namespace, attrname, td);
356 static struct vfsops null_vfsops = {
357 .vfs_extattrctl = nullfs_extattrctl,
358 .vfs_fhtovp = nullfs_fhtovp,
359 .vfs_init = nullfs_init,
360 .vfs_mount = nullfs_mount,
361 .vfs_quotactl = nullfs_quotactl,
362 .vfs_root = nullfs_root,
363 .vfs_statfs = nullfs_statfs,
364 .vfs_sync = nullfs_sync,
365 .vfs_uninit = nullfs_uninit,
366 .vfs_unmount = nullfs_unmount,
367 .vfs_vget = nullfs_vget,
370 VFS_SET(null_vfsops, nullfs, VFCF_LOOPBACK);