1 /*
2 * Copyright (c) 1992, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software donated to Berkeley by
6 * Jan-Simon Pendry.
7 *
8 * %sccs.include.redist.c%
9 *
10 * @(#)null_vfsops.c 8.7 (Berkeley) 05/14/95
11 *
12 * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
13 * $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $
14 */
15
16 /*
17 * Null Layer
18 * (See null_vnops.c for a description of what this does.)
19 */
20
21 #include <sys/param.h>
22 #include <sys/systm.h>
23 #include <sys/proc.h>
24 #include <sys/time.h>
25 #include <sys/types.h>
26 #include <sys/vnode.h>
27 #include <sys/mount.h>
28 #include <sys/namei.h>
29 #include <sys/malloc.h>
30 #include <miscfs/nullfs/null.h>
31
32 /*
33 * Mount null layer
34 */
35 int
nullfs_mount(mp,path,data,ndp,p)36 nullfs_mount(mp, path, data, ndp, p)
37 struct mount *mp;
38 char *path;
39 caddr_t data;
40 struct nameidata *ndp;
41 struct proc *p;
42 {
43 int error = 0;
44 struct null_args args;
45 struct vnode *lowerrootvp, *vp;
46 struct vnode *nullm_rootvp;
47 struct null_mount *xmp;
48 u_int size;
49
50 #ifdef NULLFS_DIAGNOSTIC
51 printf("nullfs_mount(mp = %x)\n", mp);
52 #endif
53
54 /*
55 * Update is a no-op
56 */
57 if (mp->mnt_flag & MNT_UPDATE) {
58 return (EOPNOTSUPP);
59 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
60 }
61
62 /*
63 * Get argument
64 */
65 if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args)))
66 return (error);
67
68 /*
69 * Find lower node
70 */
71 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
72 UIO_USERSPACE, args.target, p);
73 if (error = namei(ndp))
74 return (error);
75
76 /*
77 * Sanity check on lower vnode
78 */
79 lowerrootvp = ndp->ni_vp;
80
81 vrele(ndp->ni_dvp);
82 ndp->ni_dvp = NULL;
83
84 xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
85 M_UFSMNT, M_WAITOK); /* XXX */
86
87 /*
88 * Save reference to underlying FS
89 */
90 xmp->nullm_vfs = lowerrootvp->v_mount;
91
92 /*
93 * Save reference. Each mount also holds
94 * a reference on the root vnode.
95 */
96 error = null_node_create(mp, lowerrootvp, &vp);
97 /*
98 * Unlock the node (either the lower or the alias)
99 */
100 VOP_UNLOCK(vp, 0, p);
101 /*
102 * Make sure the node alias worked
103 */
104 if (error) {
105 vrele(lowerrootvp);
106 free(xmp, M_UFSMNT); /* XXX */
107 return (error);
108 }
109
110 /*
111 * Keep a held reference to the root vnode.
112 * It is vrele'd in nullfs_unmount.
113 */
114 nullm_rootvp = vp;
115 nullm_rootvp->v_flag |= VROOT;
116 xmp->nullm_rootvp = nullm_rootvp;
117 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
118 mp->mnt_flag |= MNT_LOCAL;
119 mp->mnt_data = (qaddr_t) xmp;
120 vfs_getnewfsid(mp);
121
122 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
123 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
124 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
125 &size);
126 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
127 #ifdef NULLFS_DIAGNOSTIC
128 printf("nullfs_mount: lower %s, alias at %s\n",
129 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
130 #endif
131 return (0);
132 }
133
134 /*
135 * VFS start. Nothing needed here - the start routine
136 * on the underlying filesystem will have been called
137 * when that filesystem was mounted.
138 */
139 int
nullfs_start(mp,flags,p)140 nullfs_start(mp, flags, p)
141 struct mount *mp;
142 int flags;
143 struct proc *p;
144 {
145 return (0);
146 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
147 }
148
149 /*
150 * Free reference to null layer
151 */
152 int
nullfs_unmount(mp,mntflags,p)153 nullfs_unmount(mp, mntflags, p)
154 struct mount *mp;
155 int mntflags;
156 struct proc *p;
157 {
158 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
159 int error;
160 int flags = 0;
161
162 #ifdef NULLFS_DIAGNOSTIC
163 printf("nullfs_unmount(mp = %x)\n", mp);
164 #endif
165
166 if (mntflags & MNT_FORCE)
167 flags |= FORCECLOSE;
168
169 /*
170 * Clear out buffer cache. I don't think we
171 * ever get anything cached at this level at the
172 * moment, but who knows...
173 */
174 #if 0
175 mntflushbuf(mp, 0);
176 if (mntinvalbuf(mp, 1))
177 return (EBUSY);
178 #endif
179 if (nullm_rootvp->v_usecount > 1)
180 return (EBUSY);
181 if (error = vflush(mp, nullm_rootvp, flags))
182 return (error);
183
184 #ifdef NULLFS_DIAGNOSTIC
185 vprint("alias root of lower", nullm_rootvp);
186 #endif
187 /*
188 * Release reference on underlying root vnode
189 */
190 vrele(nullm_rootvp);
191 /*
192 * And blow it away for future re-use
193 */
194 vgone(nullm_rootvp);
195 /*
196 * Finally, throw away the null_mount structure
197 */
198 free(mp->mnt_data, M_UFSMNT); /* XXX */
199 mp->mnt_data = 0;
200 return 0;
201 }
202
203 int
nullfs_root(mp,vpp)204 nullfs_root(mp, vpp)
205 struct mount *mp;
206 struct vnode **vpp;
207 {
208 struct proc *p = curproc; /* XXX */
209 struct vnode *vp;
210
211 #ifdef NULLFS_DIAGNOSTIC
212 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
213 MOUNTTONULLMOUNT(mp)->nullm_rootvp,
214 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
215 );
216 #endif
217
218 /*
219 * Return locked reference to root.
220 */
221 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
222 VREF(vp);
223 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
224 *vpp = vp;
225 return 0;
226 }
227
228 int
nullfs_quotactl(mp,cmd,uid,arg,p)229 nullfs_quotactl(mp, cmd, uid, arg, p)
230 struct mount *mp;
231 int cmd;
232 uid_t uid;
233 caddr_t arg;
234 struct proc *p;
235 {
236 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
237 }
238
239 int
nullfs_statfs(mp,sbp,p)240 nullfs_statfs(mp, sbp, p)
241 struct mount *mp;
242 struct statfs *sbp;
243 struct proc *p;
244 {
245 int error;
246 struct statfs mstat;
247
248 #ifdef NULLFS_DIAGNOSTIC
249 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
250 MOUNTTONULLMOUNT(mp)->nullm_rootvp,
251 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
252 );
253 #endif
254
255 bzero(&mstat, sizeof(mstat));
256
257 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
258 if (error)
259 return (error);
260
261 /* now copy across the "interesting" information and fake the rest */
262 sbp->f_type = mstat.f_type;
263 sbp->f_flags = mstat.f_flags;
264 sbp->f_bsize = mstat.f_bsize;
265 sbp->f_iosize = mstat.f_iosize;
266 sbp->f_blocks = mstat.f_blocks;
267 sbp->f_bfree = mstat.f_bfree;
268 sbp->f_bavail = mstat.f_bavail;
269 sbp->f_files = mstat.f_files;
270 sbp->f_ffree = mstat.f_ffree;
271 if (sbp != &mp->mnt_stat) {
272 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
273 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
274 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
275 }
276 return (0);
277 }
278
279 int
nullfs_sync(mp,waitfor,cred,p)280 nullfs_sync(mp, waitfor, cred, p)
281 struct mount *mp;
282 int waitfor;
283 struct ucred *cred;
284 struct proc *p;
285 {
286 /*
287 * XXX - Assumes no data cached at null layer.
288 */
289 return (0);
290 }
291
292 int
nullfs_vget(mp,ino,vpp)293 nullfs_vget(mp, ino, vpp)
294 struct mount *mp;
295 ino_t ino;
296 struct vnode **vpp;
297 {
298
299 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
300 }
301
302 int
nullfs_fhtovp(mp,fidp,nam,vpp,exflagsp,credanonp)303 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
304 struct mount *mp;
305 struct fid *fidp;
306 struct mbuf *nam;
307 struct vnode **vpp;
308 int *exflagsp;
309 struct ucred**credanonp;
310 {
311
312 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp);
313 }
314
315 int
nullfs_vptofh(vp,fhp)316 nullfs_vptofh(vp, fhp)
317 struct vnode *vp;
318 struct fid *fhp;
319 {
320 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
321 }
322
323 int nullfs_init __P((struct vfsconf *));
324
325 #define nullfs_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \
326 size_t, struct proc *)))eopnotsupp)
327
328 struct vfsops null_vfsops = {
329 nullfs_mount,
330 nullfs_start,
331 nullfs_unmount,
332 nullfs_root,
333 nullfs_quotactl,
334 nullfs_statfs,
335 nullfs_sync,
336 nullfs_vget,
337 nullfs_fhtovp,
338 nullfs_vptofh,
339 nullfs_init,
340 nullfs_sysctl,
341 };
342