umap_vfsops.c revision 1.39 
1/*	$NetBSD: umap_vfsops.c,v 1.39 2003/06/29 22:31:49 fvdl Exp $	*/
2
3/*
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software donated to Berkeley by
8 * the UCLA Ficus project.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	from: @(#)null_vfsops.c       1.5 (Berkeley) 7/10/92
39 *	@(#)umap_vfsops.c	8.8 (Berkeley) 5/14/95
40 */
41
42/*
43 * Umap Layer
44 * (See mount_umap(8) for a description of this layer.)
45 */
46
47#include <sys/cdefs.h>
48__KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.39 2003/06/29 22:31:49 fvdl Exp $");
49
50#include <sys/param.h>
51#include <sys/systm.h>
52#include <sys/proc.h>
53#include <sys/time.h>
54#include <sys/vnode.h>
55#include <sys/mount.h>
56#include <sys/namei.h>
57#include <sys/malloc.h>
58#include <miscfs/umapfs/umap.h>
59#include <miscfs/genfs/layer_extern.h>
60
61int	umapfs_mount __P((struct mount *, const char *, void *,
62			  struct nameidata *, struct proc *));
63int	umapfs_unmount __P((struct mount *, int, struct proc *));
64
65/*
66 * Mount umap layer
67 */
68int
69umapfs_mount(mp, path, data, ndp, p)
70	struct mount *mp;
71	const char *path;
72	void *data;
73	struct nameidata *ndp;
74	struct proc *p;
75{
76	struct umap_args args;
77	struct vnode *lowerrootvp, *vp;
78	struct umap_mount *amp;
79	int error;
80#ifdef UMAPFS_DIAGNOSTIC
81	int i;
82#endif
83	if (mp->mnt_flag & MNT_GETARGS) {
84		amp = MOUNTTOUMAPMOUNT(mp);
85		if (amp == NULL)
86			return EIO;
87		args.la.target = NULL;
88		vfs_showexport(mp, &args.la.export, &amp->umapm_export);
89		args.nentries = amp->info_nentries;
90		args.gnentries = amp->info_gnentries;
91		return copyout(&args, data, sizeof(args));
92	}
93
94	/* only for root */
95	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
96		return error;
97
98#ifdef UMAPFS_DIAGNOSTIC
99	printf("umapfs_mount(mp = %p)\n", mp);
100#endif
101
102	/*
103	 * Get argument
104	 */
105	error = copyin(data, (caddr_t)&args, sizeof(struct umap_args));
106	if (error)
107		return (error);
108
109	/*
110	 * Update only does export updating.
111	 */
112	if (mp->mnt_flag & MNT_UPDATE) {
113		amp = MOUNTTOUMAPMOUNT(mp);
114		if (args.umap_target == 0)
115			return (vfs_export(mp, &amp->umapm_export,
116					&args.umap_export));
117		else
118			return (EOPNOTSUPP);
119	}
120
121	/*
122	 * Find lower node
123	 */
124	NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
125		UIO_USERSPACE, args.umap_target, p);
126	if ((error = namei(ndp)) != 0)
127		return (error);
128
129	/*
130	 * Sanity check on lower vnode
131	 */
132	lowerrootvp = ndp->ni_vp;
133#ifdef UMAPFS_DIAGNOSTIC
134	printf("vp = %p, check for VDIR...\n", lowerrootvp);
135#endif
136
137	if (lowerrootvp->v_type != VDIR) {
138		vput(lowerrootvp);
139		return (EINVAL);
140	}
141
142#ifdef UMAPFS_DIAGNOSTIC
143	printf("mp = %p\n", mp);
144#endif
145
146	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
147				M_UFSMNT, M_WAITOK);	/* XXX */
148	memset((caddr_t)amp, 0, sizeof(struct umap_mount));
149
150	mp->mnt_data = amp;
151	amp->umapm_vfs = lowerrootvp->v_mount;
152	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
153		mp->mnt_flag |= MNT_LOCAL;
154
155	/*
156	 * Now copy in the number of entries and maps for umap mapping.
157	 */
158	if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) {
159		vput(lowerrootvp);
160		return (error);
161	}
162
163	amp->info_nentries = args.nentries;
164	amp->info_gnentries = args.gnentries;
165	error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
166	    2*sizeof(u_long)*args.nentries);
167	if (error) {
168		vput(lowerrootvp);
169		return (error);
170	}
171
172#ifdef UMAPFS_DIAGNOSTIC
173	printf("umap_mount:nentries %d\n",args.nentries);
174	for (i = 0; i < args.nentries; i++)
175		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
176	 	    amp->info_mapdata[i][1]);
177#endif
178
179	error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
180	    2*sizeof(u_long)*args.gnentries);
181	if (error) {
182		vput(lowerrootvp);
183		return (error);
184	}
185
186#ifdef UMAPFS_DIAGNOSTIC
187	printf("umap_mount:gnentries %d\n",args.gnentries);
188	for (i = 0; i < args.gnentries; i++)
189		printf("\tgroup %ld maps to %ld\n",
190		    amp->info_gmapdata[i][0],
191	 	    amp->info_gmapdata[i][1]);
192#endif
193
194	/*
195	 * Make sure the mount point's sufficiently initialized
196	 * that the node create call will work.
197	 */
198	vfs_getnewfsid(mp);
199	amp->umapm_size = sizeof(struct umap_node);
200	amp->umapm_tag = VT_UMAP;
201	amp->umapm_bypass = umap_bypass;
202	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
203	amp->umapm_vnodeop_p = umap_vnodeop_p;
204	simple_lock_init(&amp->umapm_hashlock);
205	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
206	    M_WAITOK, &amp->umapm_node_hash);
207
208
209	/*
210	 * fix up umap node for root vnode.
211	 */
212	error = layer_node_create(mp, lowerrootvp, &vp);
213	/*
214	 * Make sure the node alias worked
215	 */
216	if (error) {
217		vput(lowerrootvp);
218		free(amp, M_UFSMNT);	/* XXX */
219		return (error);
220	}
221	/*
222	 * Unlock the node (either the lower or the alias)
223	 */
224	VOP_UNLOCK(vp, 0);
225
226	/*
227	 * Keep a held reference to the root vnode.
228	 * It is vrele'd in umapfs_unmount.
229	 */
230	vp->v_flag |= VROOT;
231	amp->umapm_rootvp = vp;
232
233	error = set_statfs_info(path, UIO_USERSPACE, args.umap_target,
234	    UIO_USERSPACE, mp, p);
235#ifdef UMAPFS_DIAGNOSTIC
236	printf("umapfs_mount: lower %s, alias at %s\n",
237		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
238#endif
239	return error;
240}
241
242/*
243 * Free reference to umap layer
244 */
245int
246umapfs_unmount(mp, mntflags, p)
247	struct mount *mp;
248	int mntflags;
249	struct proc *p;
250{
251	struct vnode *rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
252	int error;
253	int flags = 0;
254
255#ifdef UMAPFS_DIAGNOSTIC
256	printf("umapfs_unmount(mp = %p)\n", mp);
257#endif
258
259	if (mntflags & MNT_FORCE)
260		flags |= FORCECLOSE;
261
262	/*
263	 * Clear out buffer cache.  I don't think we
264	 * ever get anything cached at this level at the
265	 * moment, but who knows...
266	 */
267#ifdef notyet
268	mntflushbuf(mp, 0);
269	if (mntinvalbuf(mp, 1))
270		return (EBUSY);
271#endif
272	if (rootvp->v_usecount > 1)
273		return (EBUSY);
274	if ((error = vflush(mp, rootvp, flags)) != 0)
275		return (error);
276
277#ifdef UMAPFS_DIAGNOSTIC
278	vprint("alias root of lower", rootvp);
279#endif
280	/*
281	 * Release reference on underlying root vnode
282	 */
283	vrele(rootvp);
284	/*
285	 * And blow it away for future re-use
286	 */
287	vgone(rootvp);
288	/*
289	 * Finally, throw away the umap_mount structure
290	 */
291	free(mp->mnt_data, M_UFSMNT);	/* XXX */
292	mp->mnt_data = 0;
293	return (0);
294}
295
296extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
297
298const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
299	&umapfs_vnodeop_opv_desc,
300	NULL,
301};
302
303struct vfsops umapfs_vfsops = {
304	MOUNT_UMAP,
305	umapfs_mount,
306	layerfs_start,
307	umapfs_unmount,
308	layerfs_root,
309	layerfs_quotactl,
310	layerfs_statfs,
311	layerfs_sync,
312	layerfs_vget,
313	layerfs_fhtovp,
314	layerfs_vptofh,
315	layerfs_init,
316	NULL,
317	layerfs_done,
318	layerfs_sysctl,
319	NULL,				/* vfs_mountroot */
320	layerfs_checkexp,
321	umapfs_vnodeopv_descs,
322};
323