umap_vfsops.c revision 1.56 
1/*	$NetBSD: umap_vfsops.c,v 1.56 2005/12/11 12:24:51 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 1.56 2005/12/11 12:24:51 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(struct mount *, const char *, void *,
59			  struct nameidata *, struct lwp *);
60int	umapfs_unmount(struct mount *, int, struct lwp *);
61
62/*
63 * Mount umap layer
64 */
65int
66umapfs_mount(mp, path, data, ndp, l)
67	struct mount *mp;
68	const char *path;
69	void *data;
70	struct nameidata *ndp;
71	struct lwp *l;
72{
73	struct umap_args args;
74	struct vnode *lowerrootvp, *vp;
75	struct umap_mount *amp;
76	struct proc *p = l->l_proc;
77	int error;
78#ifdef UMAPFS_DIAGNOSTIC
79	int i;
80#endif
81
82	if (mp->mnt_flag & MNT_GETARGS) {
83		amp = MOUNTTOUMAPMOUNT(mp);
84		if (amp == NULL)
85			return EIO;
86		args.la.target = NULL;
87		args.nentries = amp->info_nentries;
88		args.gnentries = amp->info_gnentries;
89		return copyout(&args, data, sizeof(args));
90	}
91
92	/* only for root */
93	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
94		return error;
95
96#ifdef UMAPFS_DIAGNOSTIC
97	printf("umapfs_mount(mp = %p)\n", mp);
98#endif
99
100	/*
101	 * Get argument
102	 */
103	error = copyin(data, &args, sizeof(struct umap_args));
104	if (error)
105		return (error);
106
107	/*
108	 * Update is not supported
109	 */
110	if (mp->mnt_flag & MNT_UPDATE)
111		return EOPNOTSUPP;
112
113	/*
114	 * Find lower node
115	 */
116	NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
117		UIO_USERSPACE, args.umap_target, l);
118	if ((error = namei(ndp)) != 0)
119		return (error);
120
121	/*
122	 * Sanity check on lower vnode
123	 */
124	lowerrootvp = ndp->ni_vp;
125#ifdef UMAPFS_DIAGNOSTIC
126	printf("vp = %p, check for VDIR...\n", lowerrootvp);
127#endif
128
129	if (lowerrootvp->v_type != VDIR) {
130		vput(lowerrootvp);
131		return (EINVAL);
132	}
133
134#ifdef UMAPFS_DIAGNOSTIC
135	printf("mp = %p\n", mp);
136#endif
137
138	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
139				M_UFSMNT, M_WAITOK);	/* XXX */
140	memset(amp, 0, sizeof(struct umap_mount));
141
142	mp->mnt_data = amp;
143	mp->mnt_leaf = lowerrootvp->v_mount->mnt_leaf;
144	amp->umapm_vfs = lowerrootvp->v_mount;
145	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
146		mp->mnt_flag |= MNT_LOCAL;
147
148	/*
149	 * Now copy in the number of entries and maps for umap mapping.
150	 */
151	if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) {
152		vput(lowerrootvp);
153		return (error);
154	}
155
156	amp->info_nentries = args.nentries;
157	amp->info_gnentries = args.gnentries;
158	error = copyin(args.mapdata, amp->info_mapdata,
159	    2*sizeof(u_long)*args.nentries);
160	if (error) {
161		vput(lowerrootvp);
162		return (error);
163	}
164
165#ifdef UMAPFS_DIAGNOSTIC
166	printf("umap_mount:nentries %d\n",args.nentries);
167	for (i = 0; i < args.nentries; i++)
168		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
169	 	    amp->info_mapdata[i][1]);
170#endif
171
172	error = copyin(args.gmapdata, amp->info_gmapdata,
173	    2*sizeof(u_long)*args.gnentries);
174	if (error) {
175		vput(lowerrootvp);
176		return (error);
177	}
178
179#ifdef UMAPFS_DIAGNOSTIC
180	printf("umap_mount:gnentries %d\n",args.gnentries);
181	for (i = 0; i < args.gnentries; i++)
182		printf("\tgroup %ld maps to %ld\n",
183		    amp->info_gmapdata[i][0],
184	 	    amp->info_gmapdata[i][1]);
185#endif
186
187	/*
188	 * Make sure the mount point's sufficiently initialized
189	 * that the node create call will work.
190	 */
191	vfs_getnewfsid(mp);
192	amp->umapm_size = sizeof(struct umap_node);
193	amp->umapm_tag = VT_UMAP;
194	amp->umapm_bypass = umap_bypass;
195	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
196	amp->umapm_vnodeop_p = umap_vnodeop_p;
197	simple_lock_init(&amp->umapm_hashlock);
198	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
199	    M_WAITOK, &amp->umapm_node_hash);
200
201
202	/*
203	 * fix up umap node for root vnode.
204	 */
205	error = layer_node_create(mp, lowerrootvp, &vp);
206	/*
207	 * Make sure the node alias worked
208	 */
209	if (error) {
210		vput(lowerrootvp);
211		free(amp, M_UFSMNT);	/* XXX */
212		return (error);
213	}
214	/*
215	 * Unlock the node (either the lower or the alias)
216	 */
217	VOP_UNLOCK(vp, 0);
218
219	/*
220	 * Keep a held reference to the root vnode.
221	 * It is vrele'd in umapfs_unmount.
222	 */
223	vp->v_flag |= VROOT;
224	amp->umapm_rootvp = vp;
225
226	error = set_statvfs_info(path, UIO_USERSPACE, args.umap_target,
227	    UIO_USERSPACE, mp, l);
228#ifdef UMAPFS_DIAGNOSTIC
229	printf("umapfs_mount: lower %s, alias at %s\n",
230		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
231#endif
232	return error;
233}
234
235/*
236 * Free reference to umap layer
237 */
238int
239umapfs_unmount(mp, mntflags, l)
240	struct mount *mp;
241	int mntflags;
242	struct lwp *l;
243{
244	struct vnode *rtvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
245	int error;
246	int flags = 0;
247
248#ifdef UMAPFS_DIAGNOSTIC
249	printf("umapfs_unmount(mp = %p)\n", mp);
250#endif
251
252	if (mntflags & MNT_FORCE)
253		flags |= FORCECLOSE;
254
255	/*
256	 * Clear out buffer cache.  I don't think we
257	 * ever get anything cached at this level at the
258	 * moment, but who knows...
259	 */
260#ifdef notyet
261	mntflushbuf(mp, 0);
262	if (mntinvalbuf(mp, 1))
263		return (EBUSY);
264#endif
265	if (rtvp->v_usecount > 1)
266		return (EBUSY);
267	if ((error = vflush(mp, rtvp, flags)) != 0)
268		return (error);
269
270#ifdef UMAPFS_DIAGNOSTIC
271	vprint("alias root of lower", rtvp);
272#endif
273	/*
274	 * Release reference on underlying root vnode
275	 */
276	vrele(rtvp);
277	/*
278	 * And blow it away for future re-use
279	 */
280	vgone(rtvp);
281	/*
282	 * Finally, throw away the umap_mount structure
283	 */
284	free(mp->mnt_data, M_UFSMNT);	/* XXX */
285	mp->mnt_data = 0;
286	return (0);
287}
288
289SYSCTL_SETUP(sysctl_vfs_umap_setup, "sysctl vfs.umap subtree setup")
290{
291
292	sysctl_createv(clog, 0, NULL, NULL,
293		       CTLFLAG_PERMANENT,
294		       CTLTYPE_NODE, "vfs", NULL,
295		       NULL, 0, NULL, 0,
296		       CTL_VFS, CTL_EOL);
297	sysctl_createv(clog, 0, NULL, NULL,
298		       CTLFLAG_PERMANENT,
299		       CTLTYPE_NODE, "umap",
300		       SYSCTL_DESCR("UID/GID remapping file system"),
301		       NULL, 0, NULL, 0,
302		       CTL_VFS, 10, CTL_EOL);
303	/*
304	 * XXX the "10" above could be dynamic, thereby eliminating
305	 * one more instance of the "number to vfs" mapping problem,
306	 * but "10" is the order as taken from sys/mount.h
307	 */
308}
309
310extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
311
312const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
313	&umapfs_vnodeop_opv_desc,
314	NULL,
315};
316
317struct vfsops umapfs_vfsops = {
318	MOUNT_UMAP,
319	umapfs_mount,
320	layerfs_start,
321	umapfs_unmount,
322	layerfs_root,
323	layerfs_quotactl,
324	layerfs_statvfs,
325	layerfs_sync,
326	layerfs_vget,
327	layerfs_fhtovp,
328	layerfs_vptofh,
329	layerfs_init,
330	NULL,
331	layerfs_done,
332	NULL,				/* vfs_mountroot */
333	layerfs_snapshot,
334	vfs_stdextattrctl,
335	umapfs_vnodeopv_descs,
336};
337VFS_ATTACH(umapfs_vfsops);
338