xref: /netbsd-src/sys/miscfs/umapfs/umap_vfsops.c (revision 5aefcfdc06931dd97e76246d2fe0302f7b3fe094)
1 /*	$NetBSD: umap_vfsops.c,v 1.26 2000/11/08 14:28:14 ad 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|WANTPARENT|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 	vrele(ndp->ni_dvp);
126 	ndp->ni_dvp = 0;
127 
128 	if (lowerrootvp->v_type != VDIR) {
129 		vput(lowerrootvp);
130 		return (EINVAL);
131 	}
132 
133 #ifdef UMAPFS_DIAGNOSTIC
134 	printf("mp = %p\n", mp);
135 #endif
136 
137 	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
138 				M_UFSMNT, M_WAITOK);	/* XXX */
139 	memset((caddr_t)amp, 0, sizeof(struct umap_mount));
140 
141 	mp->mnt_data = (qaddr_t) amp;
142 	amp->umapm_vfs = lowerrootvp->v_mount;
143 	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
144 		mp->mnt_flag |= MNT_LOCAL;
145 
146 	/*
147 	 * Now copy in the number of entries and maps for umap mapping.
148 	 */
149 	amp->info_nentries = args.nentries;
150 	amp->info_gnentries = args.gnentries;
151 	error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
152 	    2*sizeof(u_long)*args.nentries);
153 	if (error) {
154 		vput(lowerrootvp);
155 		return (error);
156 	}
157 
158 #ifdef UMAPFS_DIAGNOSTIC
159 	printf("umap_mount:nentries %d\n",args.nentries);
160 	for (i = 0; i < args.nentries; i++)
161 		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
162 	 	    amp->info_mapdata[i][1]);
163 #endif
164 
165 	error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
166 	    2*sizeof(u_long)*args.gnentries);
167 	if (error) {
168 		vput(lowerrootvp);
169 		return (error);
170 	}
171 
172 #ifdef UMAPFS_DIAGNOSTIC
173 	printf("umap_mount:gnentries %d\n",args.gnentries);
174 	for (i = 0; i < args.gnentries; i++)
175 		printf("\tgroup %ld maps to %ld\n",
176 		    amp->info_gmapdata[i][0],
177 	 	    amp->info_gmapdata[i][1]);
178 #endif
179 
180 	/*
181 	 * Make sure the mount point's sufficiently initialized
182 	 * that the node create call will work.
183 	 */
184 	vfs_getnewfsid(mp);
185 	amp->umapm_size = sizeof(struct umap_node);
186 	amp->umapm_tag = VT_UMAP;
187 	amp->umapm_bypass = umap_bypass;
188 	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
189 	amp->umapm_vnodeop_p = umap_vnodeop_p;
190 	simple_lock_init(&amp->umapm_hashlock);
191 	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
192 	    M_WAITOK, &amp->umapm_node_hash);
193 
194 
195 	/*
196 	 * fix up umap node for root vnode.
197 	 */
198 	error = layer_node_create(mp, lowerrootvp, &vp);
199 	/*
200 	 * Make sure the node alias worked
201 	 */
202 	if (error) {
203 		vput(lowerrootvp);
204 		free(amp, M_UFSMNT);	/* XXX */
205 		return (error);
206 	}
207 	/*
208 	 * Unlock the node (either the lower or the alias)
209 	 */
210 	VOP_UNLOCK(vp, 0);
211 
212 	/*
213 	 * Keep a held reference to the root vnode.
214 	 * It is vrele'd in umapfs_unmount.
215 	 */
216 	vp->v_flag |= VROOT;
217 	amp->umapm_rootvp = vp;
218 
219 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
220 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
221 	(void) copyinstr(args.umap_target, mp->mnt_stat.f_mntfromname,
222 		MNAMELEN - 1, &size);
223 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
224 #ifdef UMAPFS_DIAGNOSTIC
225 	printf("umapfs_mount: lower %s, alias at %s\n",
226 		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
227 #endif
228 	return (0);
229 }
230 
231 /*
232  * Free reference to umap layer
233  */
234 int
235 umapfs_unmount(mp, mntflags, p)
236 	struct mount *mp;
237 	int mntflags;
238 	struct proc *p;
239 {
240 	struct vnode *rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
241 	int error;
242 	int flags = 0;
243 
244 #ifdef UMAPFS_DIAGNOSTIC
245 	printf("umapfs_unmount(mp = %p)\n", mp);
246 #endif
247 
248 	if (mntflags & MNT_FORCE)
249 		flags |= FORCECLOSE;
250 
251 	/*
252 	 * Clear out buffer cache.  I don't think we
253 	 * ever get anything cached at this level at the
254 	 * moment, but who knows...
255 	 */
256 #ifdef notyet
257 	mntflushbuf(mp, 0);
258 	if (mntinvalbuf(mp, 1))
259 		return (EBUSY);
260 #endif
261 	if (rootvp->v_usecount > 1)
262 		return (EBUSY);
263 	if ((error = vflush(mp, rootvp, flags)) != 0)
264 		return (error);
265 
266 #ifdef UMAPFS_DIAGNOSTIC
267 	vprint("alias root of lower", rootvp);
268 #endif
269 	/*
270 	 * Release reference on underlying root vnode
271 	 */
272 	vrele(rootvp);
273 	/*
274 	 * And blow it away for future re-use
275 	 */
276 	vgone(rootvp);
277 	/*
278 	 * Finally, throw away the umap_mount structure
279 	 */
280 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
281 	mp->mnt_data = 0;
282 	return (0);
283 }
284 
285 extern struct vnodeopv_desc umapfs_vnodeop_opv_desc;
286 
287 struct vnodeopv_desc *umapfs_vnodeopv_descs[] = {
288 	&umapfs_vnodeop_opv_desc,
289 	NULL,
290 };
291 
292 struct vfsops umapfs_vfsops = {
293 	MOUNT_UMAP,
294 	umapfs_mount,
295 	layerfs_start,
296 	umapfs_unmount,
297 	layerfs_root,
298 	layerfs_quotactl,
299 	layerfs_statfs,
300 	layerfs_sync,
301 	layerfs_vget,
302 	layerfs_fhtovp,
303 	layerfs_vptofh,
304 	layerfs_init,
305 	layerfs_done,
306 	layerfs_sysctl,
307 	NULL,				/* vfs_mountroot */
308 	layerfs_checkexp,
309 	umapfs_vnodeopv_descs,
310 };
311