umap_vfsops.c revision 1.69 
1/*	$NetBSD: umap_vfsops.c,v 1.69 2007/07/31 21:14:16 pooka 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 1.69 2007/07/31 21:14:16 pooka 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 <sys/kauth.h>
56
57#include <miscfs/umapfs/umap.h>
58#include <miscfs/genfs/layer_extern.h>
59
60VFS_PROTOS(umapfs);
61
62/*
63 * Mount umap layer
64 */
65int
66umapfs_mount(mp, path, data, data_len, l)
67	struct mount *mp;
68	const char *path;
69	void *data;
70	size_t *data_len;
71	struct lwp *l;
72{
73	struct nameidata nd;
74	struct umap_args *args = data;
75	struct vnode *lowerrootvp, *vp;
76	struct umap_mount *amp;
77	int error;
78#ifdef UMAPFS_DIAGNOSTIC
79	int i;
80#endif
81
82	if (*data_len < sizeof *args)
83		return EINVAL;
84
85	if (mp->mnt_flag & MNT_GETARGS) {
86		amp = MOUNTTOUMAPMOUNT(mp);
87		if (amp == NULL)
88			return EIO;
89		args->la.target = NULL;
90		args->nentries = amp->info_nentries;
91		args->gnentries = amp->info_gnentries;
92		*data_len = sizeof *args;
93		return 0;
94	}
95
96	/* only for root */
97	if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
98	    NULL)) != 0)
99		return error;
100
101#ifdef UMAPFS_DIAGNOSTIC
102	printf("umapfs_mount(mp = %p)\n", mp);
103#endif
104
105	/*
106	 * Update is not supported
107	 */
108	if (mp->mnt_flag & MNT_UPDATE)
109		return EOPNOTSUPP;
110
111	/*
112	 * Find lower node
113	 */
114	NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF,
115		UIO_USERSPACE, args->umap_target, l);
116	if ((error = namei(&nd)) != 0)
117		return (error);
118
119	/*
120	 * Sanity check on lower vnode
121	 */
122	lowerrootvp = nd.ni_vp;
123#ifdef UMAPFS_DIAGNOSTIC
124	printf("vp = %p, check for VDIR...\n", lowerrootvp);
125#endif
126
127	if (lowerrootvp->v_type != VDIR) {
128		vput(lowerrootvp);
129		return (EINVAL);
130	}
131
132#ifdef UMAPFS_DIAGNOSTIC
133	printf("mp = %p\n", mp);
134#endif
135
136	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
137				M_UFSMNT, M_WAITOK);	/* XXX */
138	memset(amp, 0, sizeof(struct umap_mount));
139
140	mp->mnt_data = amp;
141	amp->umapm_vfs = lowerrootvp->v_mount;
142	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
143		mp->mnt_flag |= MNT_LOCAL;
144
145	/*
146	 * Now copy in the number of entries and maps for umap mapping.
147	 */
148	if (args->nentries > MAPFILEENTRIES || args->gnentries > GMAPFILEENTRIES) {
149		vput(lowerrootvp);
150		return (error);
151	}
152
153	amp->info_nentries = args->nentries;
154	amp->info_gnentries = args->gnentries;
155	error = copyin(args->mapdata, amp->info_mapdata,
156	    2*sizeof(u_long)*args->nentries);
157	if (error) {
158		vput(lowerrootvp);
159		return (error);
160	}
161
162#ifdef UMAPFS_DIAGNOSTIC
163	printf("umap_mount:nentries %d\n",args->nentries);
164	for (i = 0; i < args->nentries; i++)
165		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
166	 	    amp->info_mapdata[i][1]);
167#endif
168
169	error = copyin(args->gmapdata, amp->info_gmapdata,
170	    2*sizeof(u_long)*args->gnentries);
171	if (error) {
172		vput(lowerrootvp);
173		return (error);
174	}
175
176#ifdef UMAPFS_DIAGNOSTIC
177	printf("umap_mount:gnentries %d\n",args->gnentries);
178	for (i = 0; i < args->gnentries; i++)
179		printf("\tgroup %ld maps to %ld\n",
180		    amp->info_gmapdata[i][0],
181	 	    amp->info_gmapdata[i][1]);
182#endif
183
184	/*
185	 * Make sure the mount point's sufficiently initialized
186	 * that the node create call will work.
187	 */
188	vfs_getnewfsid(mp);
189	amp->umapm_size = sizeof(struct umap_node);
190	amp->umapm_tag = VT_UMAP;
191	amp->umapm_bypass = umap_bypass;
192	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
193	amp->umapm_vnodeop_p = umap_vnodeop_p;
194	simple_lock_init(&amp->umapm_hashlock);
195	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
196	    M_WAITOK, &amp->umapm_node_hash);
197
198
199	/*
200	 * fix up umap node for root vnode.
201	 */
202	error = layer_node_create(mp, lowerrootvp, &vp);
203	/*
204	 * Make sure the node alias worked
205	 */
206	if (error) {
207		vput(lowerrootvp);
208		free(amp, M_UFSMNT);	/* XXX */
209		return (error);
210	}
211	/*
212	 * Unlock the node (either the lower or the alias)
213	 */
214	VOP_UNLOCK(vp, 0);
215
216	/*
217	 * Keep a held reference to the root vnode.
218	 * It is vrele'd in umapfs_unmount.
219	 */
220	vp->v_flag |= VROOT;
221	amp->umapm_rootvp = vp;
222
223	error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target,
224	    UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
225#ifdef UMAPFS_DIAGNOSTIC
226	printf("umapfs_mount: lower %s, alias at %s\n",
227		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
228#endif
229	return error;
230}
231
232/*
233 * Free reference to umap layer
234 */
235int
236umapfs_unmount(struct mount *mp, int mntflags, struct lwp *l)
237{
238	struct vnode *rtvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
239	int error;
240	int flags = 0;
241
242#ifdef UMAPFS_DIAGNOSTIC
243	printf("umapfs_unmount(mp = %p)\n", mp);
244#endif
245
246	if (mntflags & MNT_FORCE)
247		flags |= FORCECLOSE;
248
249	if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0)
250		return (EBUSY);
251	if ((error = vflush(mp, rtvp, flags)) != 0)
252		return (error);
253
254#ifdef UMAPFS_DIAGNOSTIC
255	vprint("alias root of lower", rtvp);
256#endif
257	/*
258	 * Release reference on underlying root vnode
259	 */
260	vrele(rtvp);
261	/*
262	 * And blow it away for future re-use
263	 */
264	vgone(rtvp);
265	/*
266	 * Finally, throw away the umap_mount structure
267	 */
268	free(mp->mnt_data, M_UFSMNT);	/* XXX */
269	mp->mnt_data = 0;
270	return (0);
271}
272
273SYSCTL_SETUP(sysctl_vfs_umap_setup, "sysctl vfs.umap subtree setup")
274{
275
276	sysctl_createv(clog, 0, NULL, NULL,
277		       CTLFLAG_PERMANENT,
278		       CTLTYPE_NODE, "vfs", NULL,
279		       NULL, 0, NULL, 0,
280		       CTL_VFS, CTL_EOL);
281	sysctl_createv(clog, 0, NULL, NULL,
282		       CTLFLAG_PERMANENT,
283		       CTLTYPE_NODE, "umap",
284		       SYSCTL_DESCR("UID/GID remapping file system"),
285		       NULL, 0, NULL, 0,
286		       CTL_VFS, 10, CTL_EOL);
287	/*
288	 * XXX the "10" above could be dynamic, thereby eliminating
289	 * one more instance of the "number to vfs" mapping problem,
290	 * but "10" is the order as taken from sys/mount.h
291	 */
292}
293
294extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
295
296const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
297	&umapfs_vnodeop_opv_desc,
298	NULL,
299};
300
301struct vfsops umapfs_vfsops = {
302	MOUNT_UMAP,
303	sizeof (struct umap_args),
304	umapfs_mount,
305	layerfs_start,
306	umapfs_unmount,
307	layerfs_root,
308	layerfs_quotactl,
309	layerfs_statvfs,
310	layerfs_sync,
311	layerfs_vget,
312	layerfs_fhtovp,
313	layerfs_vptofh,
314	layerfs_init,
315	NULL,
316	layerfs_done,
317	NULL,				/* vfs_mountroot */
318	layerfs_snapshot,
319	vfs_stdextattrctl,
320	(void *)eopnotsupp,		/* vfs_suspendctl */
321	umapfs_vnodeopv_descs,
322	0,				/* vfs_refcount */
323	{ NULL, NULL },
324};
325VFS_ATTACH(umapfs_vfsops);
326