umap_vfsops.c revision 1.54 1 /* $NetBSD: umap_vfsops.c,v 1.54 2005/08/30 20:08:02 xtraeme 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 1.54 2005/08/30 20:08:02 xtraeme 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 proc *);
60 int umapfs_unmount(struct mount *, int, struct proc *);
61
62 /*
63 * Mount umap layer
64 */
65 int
66 umapfs_mount(mp, path, data, ndp, p)
67 struct mount *mp;
68 const char *path;
69 void *data;
70 struct nameidata *ndp;
71 struct proc *p;
72 {
73 struct umap_args args;
74 struct vnode *lowerrootvp, *vp;
75 struct umap_mount *amp;
76 int error;
77 #ifdef UMAPFS_DIAGNOSTIC
78 int i;
79 #endif
80 if (mp->mnt_flag & MNT_GETARGS) {
81 amp = MOUNTTOUMAPMOUNT(mp);
82 if (amp == NULL)
83 return EIO;
84 args.la.target = NULL;
85 vfs_showexport(mp, &args.la.export, &->umapm_export);
86 args.nentries = amp->info_nentries;
87 args.gnentries = amp->info_gnentries;
88 return copyout(&args, data, sizeof(args));
89 }
90
91 /* only for root */
92 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
93 return error;
94
95 #ifdef UMAPFS_DIAGNOSTIC
96 printf("umapfs_mount(mp = %p)\n", mp);
97 #endif
98
99 /*
100 * Get argument
101 */
102 error = copyin(data, &args, sizeof(struct umap_args));
103 if (error)
104 return (error);
105
106 /*
107 * Update only does export updating.
108 */
109 if (mp->mnt_flag & MNT_UPDATE) {
110 amp = MOUNTTOUMAPMOUNT(mp);
111 if (args.umap_target == 0)
112 return (vfs_export(mp, &->umapm_export,
113 &args.umap_export));
114 else
115 return (EOPNOTSUPP);
116 }
117
118 /*
119 * Find lower node
120 */
121 NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
122 UIO_USERSPACE, args.umap_target, p);
123 if ((error = namei(ndp)) != 0)
124 return (error);
125
126 /*
127 * Sanity check on lower vnode
128 */
129 lowerrootvp = ndp->ni_vp;
130 #ifdef UMAPFS_DIAGNOSTIC
131 printf("vp = %p, check for VDIR...\n", lowerrootvp);
132 #endif
133
134 if (lowerrootvp->v_type != VDIR) {
135 vput(lowerrootvp);
136 return (EINVAL);
137 }
138
139 #ifdef UMAPFS_DIAGNOSTIC
140 printf("mp = %p\n", mp);
141 #endif
142
143 amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
144 M_UFSMNT, M_WAITOK); /* XXX */
145 memset(amp, 0, sizeof(struct umap_mount));
146
147 mp->mnt_data = amp;
148 mp->mnt_leaf = lowerrootvp->v_mount->mnt_leaf;
149 amp->umapm_vfs = lowerrootvp->v_mount;
150 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
151 mp->mnt_flag |= MNT_LOCAL;
152
153 /*
154 * Now copy in the number of entries and maps for umap mapping.
155 */
156 if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) {
157 vput(lowerrootvp);
158 return (error);
159 }
160
161 amp->info_nentries = args.nentries;
162 amp->info_gnentries = args.gnentries;
163 error = copyin(args.mapdata, amp->info_mapdata,
164 2*sizeof(u_long)*args.nentries);
165 if (error) {
166 vput(lowerrootvp);
167 return (error);
168 }
169
170 #ifdef UMAPFS_DIAGNOSTIC
171 printf("umap_mount:nentries %d\n",args.nentries);
172 for (i = 0; i < args.nentries; i++)
173 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0],
174 amp->info_mapdata[i][1]);
175 #endif
176
177 error = copyin(args.gmapdata, amp->info_gmapdata,
178 2*sizeof(u_long)*args.gnentries);
179 if (error) {
180 vput(lowerrootvp);
181 return (error);
182 }
183
184 #ifdef UMAPFS_DIAGNOSTIC
185 printf("umap_mount:gnentries %d\n",args.gnentries);
186 for (i = 0; i < args.gnentries; i++)
187 printf("\tgroup %ld maps to %ld\n",
188 amp->info_gmapdata[i][0],
189 amp->info_gmapdata[i][1]);
190 #endif
191
192 /*
193 * Make sure the mount point's sufficiently initialized
194 * that the node create call will work.
195 */
196 vfs_getnewfsid(mp);
197 amp->umapm_size = sizeof(struct umap_node);
198 amp->umapm_tag = VT_UMAP;
199 amp->umapm_bypass = umap_bypass;
200 amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */
201 amp->umapm_vnodeop_p = umap_vnodeop_p;
202 simple_lock_init(&->umapm_hashlock);
203 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
204 M_WAITOK, &->umapm_node_hash);
205
206
207 /*
208 * fix up umap node for root vnode.
209 */
210 error = layer_node_create(mp, lowerrootvp, &vp);
211 /*
212 * Make sure the node alias worked
213 */
214 if (error) {
215 vput(lowerrootvp);
216 free(amp, M_UFSMNT); /* XXX */
217 return (error);
218 }
219 /*
220 * Unlock the node (either the lower or the alias)
221 */
222 VOP_UNLOCK(vp, 0);
223
224 /*
225 * Keep a held reference to the root vnode.
226 * It is vrele'd in umapfs_unmount.
227 */
228 vp->v_flag |= VROOT;
229 amp->umapm_rootvp = vp;
230
231 error = set_statvfs_info(path, UIO_USERSPACE, args.umap_target,
232 UIO_USERSPACE, mp, p);
233 #ifdef UMAPFS_DIAGNOSTIC
234 printf("umapfs_mount: lower %s, alias at %s\n",
235 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
236 #endif
237 return error;
238 }
239
240 /*
241 * Free reference to umap layer
242 */
243 int
244 umapfs_unmount(mp, mntflags, p)
245 struct mount *mp;
246 int mntflags;
247 struct proc *p;
248 {
249 struct vnode *rtvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
250 int error;
251 int flags = 0;
252
253 #ifdef UMAPFS_DIAGNOSTIC
254 printf("umapfs_unmount(mp = %p)\n", mp);
255 #endif
256
257 if (mntflags & MNT_FORCE)
258 flags |= FORCECLOSE;
259
260 /*
261 * Clear out buffer cache. I don't think we
262 * ever get anything cached at this level at the
263 * moment, but who knows...
264 */
265 #ifdef notyet
266 mntflushbuf(mp, 0);
267 if (mntinvalbuf(mp, 1))
268 return (EBUSY);
269 #endif
270 if (rtvp->v_usecount > 1)
271 return (EBUSY);
272 if ((error = vflush(mp, rtvp, flags)) != 0)
273 return (error);
274
275 #ifdef UMAPFS_DIAGNOSTIC
276 vprint("alias root of lower", rtvp);
277 #endif
278 /*
279 * Release reference on underlying root vnode
280 */
281 vrele(rtvp);
282 /*
283 * And blow it away for future re-use
284 */
285 vgone(rtvp);
286 /*
287 * Finally, throw away the umap_mount structure
288 */
289 free(mp->mnt_data, M_UFSMNT); /* XXX */
290 mp->mnt_data = 0;
291 return (0);
292 }
293
294 SYSCTL_SETUP(sysctl_vfs_umap_setup, "sysctl vfs.umap subtree setup")
295 {
296
297 sysctl_createv(clog, 0, NULL, NULL,
298 CTLFLAG_PERMANENT,
299 CTLTYPE_NODE, "vfs", NULL,
300 NULL, 0, NULL, 0,
301 CTL_VFS, CTL_EOL);
302 sysctl_createv(clog, 0, NULL, NULL,
303 CTLFLAG_PERMANENT,
304 CTLTYPE_NODE, "umap",
305 SYSCTL_DESCR("UID/GID remapping file system"),
306 NULL, 0, NULL, 0,
307 CTL_VFS, 10, CTL_EOL);
308 /*
309 * XXX the "10" above could be dynamic, thereby eliminating
310 * one more instance of the "number to vfs" mapping problem,
311 * but "10" is the order as taken from sys/mount.h
312 */
313 }
314
315 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
316
317 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
318 &umapfs_vnodeop_opv_desc,
319 NULL,
320 };
321
322 struct vfsops umapfs_vfsops = {
323 MOUNT_UMAP,
324 umapfs_mount,
325 layerfs_start,
326 umapfs_unmount,
327 layerfs_root,
328 layerfs_quotactl,
329 layerfs_statvfs,
330 layerfs_sync,
331 layerfs_vget,
332 layerfs_fhtovp,
333 layerfs_vptofh,
334 layerfs_init,
335 NULL,
336 layerfs_done,
337 NULL,
338 NULL, /* vfs_mountroot */
339 layerfs_checkexp,
340 layerfs_snapshot,
341 vfs_stdextattrctl,
342 umapfs_vnodeopv_descs,
343 };
344 VFS_ATTACH(umapfs_vfsops);
345