xref: /netbsd-src/sys/miscfs/umapfs/umap_vfsops.c (revision 27578b9aac214cc7796ead81dcc5427e79d5f2a0)
1 /*	$NetBSD: umap_vfsops.c,v 1.31 2001/09/15 16:13:00 chs 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/param.h>
48 #include <sys/systm.h>
49 #include <sys/proc.h>
50 #include <sys/time.h>
51 #include <sys/types.h>
52 #include <sys/vnode.h>
53 #include <sys/mount.h>
54 #include <sys/namei.h>
55 #include <sys/malloc.h>
56 #include <miscfs/umapfs/umap.h>
57 #include <miscfs/genfs/layer_extern.h>
58 
59 int	umapfs_mount __P((struct mount *, const char *, void *,
60 			  struct nameidata *, struct proc *));
61 int	umapfs_unmount __P((struct mount *, int, struct proc *));
62 
63 /*
64  * Mount umap layer
65  */
66 int
67 umapfs_mount(mp, path, data, ndp, p)
68 	struct mount *mp;
69 	const char *path;
70 	void *data;
71 	struct nameidata *ndp;
72 	struct proc *p;
73 {
74 	struct umap_args args;
75 	struct vnode *lowerrootvp, *vp;
76 	struct umap_mount *amp;
77 	size_t size;
78 	int error;
79 #ifdef UMAPFS_DIAGNOSTIC
80 	int i;
81 #endif
82 
83 	/* only for root */
84 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
85 		return error;
86 
87 #ifdef UMAPFS_DIAGNOSTIC
88 	printf("umapfs_mount(mp = %p)\n", mp);
89 #endif
90 
91 	/*
92 	 * Get argument
93 	 */
94 	error = copyin(data, (caddr_t)&args, sizeof(struct umap_args));
95 	if (error)
96 		return (error);
97 
98 	/*
99 	 * Update only does export updating.
100 	 */
101 	if (mp->mnt_flag & MNT_UPDATE) {
102 		amp = MOUNTTOUMAPMOUNT(mp);
103 		if (args.umap_target == 0)
104 			return (vfs_export(mp, &amp->umapm_export,
105 					&args.umap_export));
106 		else
107 			return (EOPNOTSUPP);
108 	}
109 
110 	/*
111 	 * Find lower node
112 	 */
113 	NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
114 		UIO_USERSPACE, args.umap_target, p);
115 	if ((error = namei(ndp)) != 0)
116 		return (error);
117 
118 	/*
119 	 * Sanity check on lower vnode
120 	 */
121 	lowerrootvp = ndp->ni_vp;
122 #ifdef UMAPFS_DIAGNOSTIC
123 	printf("vp = %p, check for VDIR...\n", lowerrootvp);
124 #endif
125 
126 	if (lowerrootvp->v_type != VDIR) {
127 		vput(lowerrootvp);
128 		return (EINVAL);
129 	}
130 
131 #ifdef UMAPFS_DIAGNOSTIC
132 	printf("mp = %p\n", mp);
133 #endif
134 
135 	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
136 				M_UFSMNT, M_WAITOK);	/* XXX */
137 	memset((caddr_t)amp, 0, sizeof(struct umap_mount));
138 
139 	mp->mnt_data = (qaddr_t) amp;
140 	amp->umapm_vfs = lowerrootvp->v_mount;
141 	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
142 		mp->mnt_flag |= MNT_LOCAL;
143 
144 	/*
145 	 * Now copy in the number of entries and maps for umap mapping.
146 	 */
147 	if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) {
148 		vput(lowerrootvp);
149 		return (error);
150 	}
151 
152 	amp->info_nentries = args.nentries;
153 	amp->info_gnentries = args.gnentries;
154 	error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
155 	    2*sizeof(u_long)*args.nentries);
156 	if (error) {
157 		vput(lowerrootvp);
158 		return (error);
159 	}
160 
161 #ifdef UMAPFS_DIAGNOSTIC
162 	printf("umap_mount:nentries %d\n",args.nentries);
163 	for (i = 0; i < args.nentries; i++)
164 		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
165 	 	    amp->info_mapdata[i][1]);
166 #endif
167 
168 	error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
169 	    2*sizeof(u_long)*args.gnentries);
170 	if (error) {
171 		vput(lowerrootvp);
172 		return (error);
173 	}
174 
175 #ifdef UMAPFS_DIAGNOSTIC
176 	printf("umap_mount:gnentries %d\n",args.gnentries);
177 	for (i = 0; i < args.gnentries; i++)
178 		printf("\tgroup %ld maps to %ld\n",
179 		    amp->info_gmapdata[i][0],
180 	 	    amp->info_gmapdata[i][1]);
181 #endif
182 
183 	/*
184 	 * Make sure the mount point's sufficiently initialized
185 	 * that the node create call will work.
186 	 */
187 	vfs_getnewfsid(mp);
188 	amp->umapm_size = sizeof(struct umap_node);
189 	amp->umapm_tag = VT_UMAP;
190 	amp->umapm_bypass = umap_bypass;
191 	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
192 	amp->umapm_vnodeop_p = umap_vnodeop_p;
193 	simple_lock_init(&amp->umapm_hashlock);
194 	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
195 	    M_WAITOK, &amp->umapm_node_hash);
196 
197 
198 	/*
199 	 * fix up umap node for root vnode.
200 	 */
201 	error = layer_node_create(mp, lowerrootvp, &vp);
202 	/*
203 	 * Make sure the node alias worked
204 	 */
205 	if (error) {
206 		vput(lowerrootvp);
207 		free(amp, M_UFSMNT);	/* XXX */
208 		return (error);
209 	}
210 	/*
211 	 * Unlock the node (either the lower or the alias)
212 	 */
213 	VOP_UNLOCK(vp, 0);
214 
215 	/*
216 	 * Keep a held reference to the root vnode.
217 	 * It is vrele'd in umapfs_unmount.
218 	 */
219 	vp->v_flag |= VROOT;
220 	amp->umapm_rootvp = vp;
221 
222 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
223 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
224 	(void) copyinstr(args.umap_target, mp->mnt_stat.f_mntfromname,
225 		MNAMELEN - 1, &size);
226 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
227 #ifdef UMAPFS_DIAGNOSTIC
228 	printf("umapfs_mount: lower %s, alias at %s\n",
229 		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
230 #endif
231 	return (0);
232 }
233 
234 /*
235  * Free reference to umap layer
236  */
237 int
238 umapfs_unmount(mp, mntflags, p)
239 	struct mount *mp;
240 	int mntflags;
241 	struct proc *p;
242 {
243 	struct vnode *rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
244 	int error;
245 	int flags = 0;
246 
247 #ifdef UMAPFS_DIAGNOSTIC
248 	printf("umapfs_unmount(mp = %p)\n", mp);
249 #endif
250 
251 	if (mntflags & MNT_FORCE)
252 		flags |= FORCECLOSE;
253 
254 	/*
255 	 * Clear out buffer cache.  I don't think we
256 	 * ever get anything cached at this level at the
257 	 * moment, but who knows...
258 	 */
259 #ifdef notyet
260 	mntflushbuf(mp, 0);
261 	if (mntinvalbuf(mp, 1))
262 		return (EBUSY);
263 #endif
264 	if (rootvp->v_usecount > 1)
265 		return (EBUSY);
266 	if ((error = vflush(mp, rootvp, flags)) != 0)
267 		return (error);
268 
269 #ifdef UMAPFS_DIAGNOSTIC
270 	vprint("alias root of lower", rootvp);
271 #endif
272 	/*
273 	 * Release reference on underlying root vnode
274 	 */
275 	vrele(rootvp);
276 	/*
277 	 * And blow it away for future re-use
278 	 */
279 	vgone(rootvp);
280 	/*
281 	 * Finally, throw away the umap_mount structure
282 	 */
283 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
284 	mp->mnt_data = 0;
285 	return (0);
286 }
287 
288 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
289 
290 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
291 	&umapfs_vnodeop_opv_desc,
292 	NULL,
293 };
294 
295 struct vfsops umapfs_vfsops = {
296 	MOUNT_UMAP,
297 	umapfs_mount,
298 	layerfs_start,
299 	umapfs_unmount,
300 	layerfs_root,
301 	layerfs_quotactl,
302 	layerfs_statfs,
303 	layerfs_sync,
304 	layerfs_vget,
305 	layerfs_fhtovp,
306 	layerfs_vptofh,
307 	layerfs_init,
308 	NULL,
309 	layerfs_done,
310 	layerfs_sysctl,
311 	NULL,				/* vfs_mountroot */
312 	layerfs_checkexp,
313 	umapfs_vnodeopv_descs,
314 };
315