umap_vfsops.c revision 1.77 1 /* $NetBSD: umap_vfsops.c,v 1.77 2008/05/05 17:11:17 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. 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 1.77 2008/05/05 17:11:17 ad 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
60 VFS_PROTOS(umapfs);
61
62 /*
63 * Mount umap layer
64 */
65 int
66 umapfs_mount(mp, path, data, data_len)
67 struct mount *mp;
68 const char *path;
69 void *data;
70 size_t *data_len;
71 {
72 struct lwp *l = curlwp;
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);
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 mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE);
195 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true,
196 &->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 hashdone(amp->umapm_node_hashtbl, HASH_LIST,
209 amp->umapm_node_hash);
210 free(amp, M_UFSMNT); /* XXX */
211 return (error);
212 }
213 /*
214 * Unlock the node (either the lower or the alias)
215 */
216 vp->v_vflag |= VV_ROOT;
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 amp->umapm_rootvp = vp;
224
225 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target,
226 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
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 error;
232 }
233
234 /*
235 * Free reference to umap layer
236 */
237 int
238 umapfs_unmount(struct mount *mp, int mntflags)
239 {
240 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp);
241 struct vnode *rtvp = amp->umapm_rootvp;
242 int error;
243 int flags = 0;
244
245 #ifdef UMAPFS_DIAGNOSTIC
246 printf("umapfs_unmount(mp = %p)\n", mp);
247 #endif
248
249 if (mntflags & MNT_FORCE)
250 flags |= FORCECLOSE;
251
252 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0)
253 return (EBUSY);
254 if ((error = vflush(mp, rtvp, flags)) != 0)
255 return (error);
256
257 #ifdef UMAPFS_DIAGNOSTIC
258 vprint("alias root of lower", rtvp);
259 #endif
260 /*
261 * Blow it away for future re-use
262 */
263 vgone(rtvp);
264 /*
265 * Finally, throw away the umap_mount structure
266 */
267 mutex_destroy(&->umapm_hashlock);
268 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash);
269 free(amp, M_UFSMNT); /* XXX */
270 mp->mnt_data = 0;
271 return (0);
272 }
273
274 SYSCTL_SETUP(sysctl_vfs_umap_setup, "sysctl vfs.umap subtree setup")
275 {
276
277 sysctl_createv(clog, 0, NULL, NULL,
278 CTLFLAG_PERMANENT,
279 CTLTYPE_NODE, "vfs", NULL,
280 NULL, 0, NULL, 0,
281 CTL_VFS, CTL_EOL);
282 sysctl_createv(clog, 0, NULL, NULL,
283 CTLFLAG_PERMANENT,
284 CTLTYPE_NODE, "umap",
285 SYSCTL_DESCR("UID/GID remapping file system"),
286 NULL, 0, NULL, 0,
287 CTL_VFS, 10, CTL_EOL);
288 /*
289 * XXX the "10" above could be dynamic, thereby eliminating
290 * one more instance of the "number to vfs" mapping problem,
291 * but "10" is the order as taken from sys/mount.h
292 */
293 }
294
295 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
296
297 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
298 &umapfs_vnodeop_opv_desc,
299 NULL,
300 };
301
302 struct vfsops umapfs_vfsops = {
303 MOUNT_UMAP,
304 sizeof (struct umap_args),
305 umapfs_mount,
306 layerfs_start,
307 umapfs_unmount,
308 layerfs_root,
309 layerfs_quotactl,
310 layerfs_statvfs,
311 layerfs_sync,
312 layerfs_vget,
313 layerfs_fhtovp,
314 layerfs_vptofh,
315 layerfs_init,
316 NULL,
317 layerfs_done,
318 NULL, /* vfs_mountroot */
319 layerfs_snapshot,
320 vfs_stdextattrctl,
321 (void *)eopnotsupp, /* vfs_suspendctl */
322 layerfs_renamelock_enter,
323 layerfs_renamelock_exit,
324 (void *)eopnotsupp,
325 umapfs_vnodeopv_descs,
326 0, /* vfs_refcount */
327 { NULL, NULL },
328 };
329 VFS_ATTACH(umapfs_vfsops);
330