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
58 int umapfs_mount(struct mount *, const char *, void *,
59 struct nameidata *, struct lwp *);
60 int umapfs_unmount(struct mount *, int, struct lwp *);
61
62 /*
63 * Mount umap layer
64 */
65 int
66 umapfs_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(&->umapm_hashlock);
198 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
199 M_WAITOK, &->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 */
238 int
239 umapfs_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
289 SYSCTL_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
310 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
311
312 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
313 &umapfs_vnodeop_opv_desc,
314 NULL,
315 };
316
317 struct 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 };
337 VFS_ATTACH(umapfs_vfsops);
338