umap_vfsops.c revision 1.53
1/*	$NetBSD: umap_vfsops.c,v 1.53 2005/05/29 21:55:34 christos 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. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	from: @(#)null_vfsops.c       1.5 (Berkeley) 7/10/92
35 *	@(#)umap_vfsops.c	8.8 (Berkeley) 5/14/95
36 */
37
38/*
39 * Umap Layer
40 * (See mount_umap(8) for a description of this layer.)
41 */
42
43#include <sys/cdefs.h>
44__KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.53 2005/05/29 21:55:34 christos Exp $");
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/sysctl.h>
49#include <sys/proc.h>
50#include <sys/time.h>
51#include <sys/vnode.h>
52#include <sys/mount.h>
53#include <sys/namei.h>
54#include <sys/malloc.h>
55#include <miscfs/umapfs/umap.h>
56#include <miscfs/genfs/layer_extern.h>
57
58int	umapfs_mount __P((struct mount *, const char *, void *,
59			  struct nameidata *, struct proc *));
60int	umapfs_unmount __P((struct mount *, int, struct proc *));
61
62/*
63 * Mount umap layer
64 */
65int
66umapfs_mount(mp, path, data, ndp, p)
67	struct mount *mp;
68	const char *path;
69	void *data;
70	struct nameidata *ndp;
71	struct proc *p;
72{
73	struct umap_args args;
74	struct vnode *lowerrootvp, *vp;
75	struct umap_mount *amp;
76	int error;
77#ifdef UMAPFS_DIAGNOSTIC
78	int i;
79#endif
80	if (mp->mnt_flag & MNT_GETARGS) {
81		amp = MOUNTTOUMAPMOUNT(mp);
82		if (amp == NULL)
83			return EIO;
84		args.la.target = NULL;
85		vfs_showexport(mp, &args.la.export, &amp->umapm_export);
86		args.nentries = amp->info_nentries;
87		args.gnentries = amp->info_gnentries;
88		return copyout(&args, data, sizeof(args));
89	}
90
91	/* only for root */
92	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
93		return error;
94
95#ifdef UMAPFS_DIAGNOSTIC
96	printf("umapfs_mount(mp = %p)\n", mp);
97#endif
98
99	/*
100	 * Get argument
101	 */
102	error = copyin(data, &args, sizeof(struct umap_args));
103	if (error)
104		return (error);
105
106	/*
107	 * Update only does export updating.
108	 */
109	if (mp->mnt_flag & MNT_UPDATE) {
110		amp = MOUNTTOUMAPMOUNT(mp);
111		if (args.umap_target == 0)
112			return (vfs_export(mp, &amp->umapm_export,
113					&args.umap_export));
114		else
115			return (EOPNOTSUPP);
116	}
117
118	/*
119	 * Find lower node
120	 */
121	NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
122		UIO_USERSPACE, args.umap_target, p);
123	if ((error = namei(ndp)) != 0)
124		return (error);
125
126	/*
127	 * Sanity check on lower vnode
128	 */
129	lowerrootvp = ndp->ni_vp;
130#ifdef UMAPFS_DIAGNOSTIC
131	printf("vp = %p, check for VDIR...\n", lowerrootvp);
132#endif
133
134	if (lowerrootvp->v_type != VDIR) {
135		vput(lowerrootvp);
136		return (EINVAL);
137	}
138
139#ifdef UMAPFS_DIAGNOSTIC
140	printf("mp = %p\n", mp);
141#endif
142
143	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
144				M_UFSMNT, M_WAITOK);	/* XXX */
145	memset(amp, 0, sizeof(struct umap_mount));
146
147	mp->mnt_data = amp;
148	mp->mnt_leaf = lowerrootvp->v_mount->mnt_leaf;
149	amp->umapm_vfs = lowerrootvp->v_mount;
150	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
151		mp->mnt_flag |= MNT_LOCAL;
152
153	/*
154	 * Now copy in the number of entries and maps for umap mapping.
155	 */
156	if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) {
157		vput(lowerrootvp);
158		return (error);
159	}
160
161	amp->info_nentries = args.nentries;
162	amp->info_gnentries = args.gnentries;
163	error = copyin(args.mapdata, amp->info_mapdata,
164	    2*sizeof(u_long)*args.nentries);
165	if (error) {
166		vput(lowerrootvp);
167		return (error);
168	}
169
170#ifdef UMAPFS_DIAGNOSTIC
171	printf("umap_mount:nentries %d\n",args.nentries);
172	for (i = 0; i < args.nentries; i++)
173		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
174	 	    amp->info_mapdata[i][1]);
175#endif
176
177	error = copyin(args.gmapdata, amp->info_gmapdata,
178	    2*sizeof(u_long)*args.gnentries);
179	if (error) {
180		vput(lowerrootvp);
181		return (error);
182	}
183
184#ifdef UMAPFS_DIAGNOSTIC
185	printf("umap_mount:gnentries %d\n",args.gnentries);
186	for (i = 0; i < args.gnentries; i++)
187		printf("\tgroup %ld maps to %ld\n",
188		    amp->info_gmapdata[i][0],
189	 	    amp->info_gmapdata[i][1]);
190#endif
191
192	/*
193	 * Make sure the mount point's sufficiently initialized
194	 * that the node create call will work.
195	 */
196	vfs_getnewfsid(mp);
197	amp->umapm_size = sizeof(struct umap_node);
198	amp->umapm_tag = VT_UMAP;
199	amp->umapm_bypass = umap_bypass;
200	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
201	amp->umapm_vnodeop_p = umap_vnodeop_p;
202	simple_lock_init(&amp->umapm_hashlock);
203	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
204	    M_WAITOK, &amp->umapm_node_hash);
205
206
207	/*
208	 * fix up umap node for root vnode.
209	 */
210	error = layer_node_create(mp, lowerrootvp, &vp);
211	/*
212	 * Make sure the node alias worked
213	 */
214	if (error) {
215		vput(lowerrootvp);
216		free(amp, M_UFSMNT);	/* XXX */
217		return (error);
218	}
219	/*
220	 * Unlock the node (either the lower or the alias)
221	 */
222	VOP_UNLOCK(vp, 0);
223
224	/*
225	 * Keep a held reference to the root vnode.
226	 * It is vrele'd in umapfs_unmount.
227	 */
228	vp->v_flag |= VROOT;
229	amp->umapm_rootvp = vp;
230
231	error = set_statvfs_info(path, UIO_USERSPACE, args.umap_target,
232	    UIO_USERSPACE, mp, p);
233#ifdef UMAPFS_DIAGNOSTIC
234	printf("umapfs_mount: lower %s, alias at %s\n",
235		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
236#endif
237	return error;
238}
239
240/*
241 * Free reference to umap layer
242 */
243int
244umapfs_unmount(mp, mntflags, p)
245	struct mount *mp;
246	int mntflags;
247	struct proc *p;
248{
249	struct vnode *rtvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
250	int error;
251	int flags = 0;
252
253#ifdef UMAPFS_DIAGNOSTIC
254	printf("umapfs_unmount(mp = %p)\n", mp);
255#endif
256
257	if (mntflags & MNT_FORCE)
258		flags |= FORCECLOSE;
259
260	/*
261	 * Clear out buffer cache.  I don't think we
262	 * ever get anything cached at this level at the
263	 * moment, but who knows...
264	 */
265#ifdef notyet
266	mntflushbuf(mp, 0);
267	if (mntinvalbuf(mp, 1))
268		return (EBUSY);
269#endif
270	if (rtvp->v_usecount > 1)
271		return (EBUSY);
272	if ((error = vflush(mp, rtvp, flags)) != 0)
273		return (error);
274
275#ifdef UMAPFS_DIAGNOSTIC
276	vprint("alias root of lower", rtvp);
277#endif
278	/*
279	 * Release reference on underlying root vnode
280	 */
281	vrele(rtvp);
282	/*
283	 * And blow it away for future re-use
284	 */
285	vgone(rtvp);
286	/*
287	 * Finally, throw away the umap_mount structure
288	 */
289	free(mp->mnt_data, M_UFSMNT);	/* XXX */
290	mp->mnt_data = 0;
291	return (0);
292}
293
294SYSCTL_SETUP(sysctl_vfs_umap_setup, "sysctl vfs.umap subtree setup")
295{
296
297	sysctl_createv(clog, 0, NULL, NULL,
298		       CTLFLAG_PERMANENT,
299		       CTLTYPE_NODE, "vfs", NULL,
300		       NULL, 0, NULL, 0,
301		       CTL_VFS, CTL_EOL);
302	sysctl_createv(clog, 0, NULL, NULL,
303		       CTLFLAG_PERMANENT,
304		       CTLTYPE_NODE, "umap",
305		       SYSCTL_DESCR("UID/GID remapping file system"),
306		       NULL, 0, NULL, 0,
307		       CTL_VFS, 10, CTL_EOL);
308	/*
309	 * XXX the "10" above could be dynamic, thereby eliminating
310	 * one more instance of the "number to vfs" mapping problem,
311	 * but "10" is the order as taken from sys/mount.h
312	 */
313}
314
315extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
316
317const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
318	&umapfs_vnodeop_opv_desc,
319	NULL,
320};
321
322struct vfsops umapfs_vfsops = {
323	MOUNT_UMAP,
324	umapfs_mount,
325	layerfs_start,
326	umapfs_unmount,
327	layerfs_root,
328	layerfs_quotactl,
329	layerfs_statvfs,
330	layerfs_sync,
331	layerfs_vget,
332	layerfs_fhtovp,
333	layerfs_vptofh,
334	layerfs_init,
335	NULL,
336	layerfs_done,
337	NULL,
338	NULL,				/* vfs_mountroot */
339	layerfs_checkexp,
340	layerfs_snapshot,
341	vfs_stdextattrctl,
342	umapfs_vnodeopv_descs,
343};
344VFS_ATTACH(umapfs_vfsops);
345