1 | /* $NetBSD: umap_vfsops.c,v 1.95 2014/11/09 18:08:07 maxv 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 1.95 2014/11/09 18:08:07 maxv 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/kauth.h> |
55 | #include <sys/module.h> |
56 | |
57 | #include <miscfs/umapfs/umap.h> |
58 | #include <miscfs/genfs/layer_extern.h> |
59 | |
60 | MODULE(MODULE_CLASS_VFS, umap, "layerfs" ); |
61 | |
62 | VFS_PROTOS(umapfs); |
63 | |
64 | static struct sysctllog *umapfs_sysctl_log; |
65 | |
66 | /* |
67 | * Mount umap layer |
68 | */ |
69 | int |
70 | umapfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) |
71 | { |
72 | struct lwp *l = curlwp; |
73 | struct pathbuf *pb; |
74 | struct nameidata nd; |
75 | struct umap_args *args = data; |
76 | struct vnode *lowerrootvp, *vp; |
77 | struct umap_mount *amp; |
78 | int error; |
79 | #ifdef UMAPFS_DIAGNOSTIC |
80 | int i; |
81 | #endif |
82 | |
83 | if (args == NULL) |
84 | return EINVAL; |
85 | if (*data_len < sizeof *args) |
86 | return EINVAL; |
87 | |
88 | if (mp->mnt_flag & MNT_GETARGS) { |
89 | amp = MOUNTTOUMAPMOUNT(mp); |
90 | if (amp == NULL) |
91 | return EIO; |
92 | args->la.target = NULL; |
93 | args->nentries = amp->info_nentries; |
94 | args->gnentries = amp->info_gnentries; |
95 | *data_len = sizeof *args; |
96 | return 0; |
97 | } |
98 | |
99 | /* only for root */ |
100 | error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, |
101 | KAUTH_REQ_SYSTEM_MOUNT_UMAP, NULL, NULL, NULL); |
102 | if (error) |
103 | return error; |
104 | |
105 | #ifdef UMAPFS_DIAGNOSTIC |
106 | printf("umapfs_mount(mp = %p)\n" , mp); |
107 | #endif |
108 | |
109 | /* |
110 | * Update is not supported |
111 | */ |
112 | if (mp->mnt_flag & MNT_UPDATE) |
113 | return EOPNOTSUPP; |
114 | |
115 | /* |
116 | * Find lower node |
117 | */ |
118 | error = pathbuf_copyin(args->umap_target, &pb); |
119 | if (error) { |
120 | return error; |
121 | } |
122 | NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); |
123 | if ((error = namei(&nd)) != 0) { |
124 | pathbuf_destroy(pb); |
125 | return error; |
126 | } |
127 | |
128 | /* |
129 | * Sanity check on lower vnode |
130 | */ |
131 | lowerrootvp = nd.ni_vp; |
132 | pathbuf_destroy(pb); |
133 | #ifdef UMAPFS_DIAGNOSTIC |
134 | printf("vp = %p, check for VDIR...\n" , lowerrootvp); |
135 | #endif |
136 | |
137 | if (lowerrootvp->v_type != VDIR) { |
138 | vput(lowerrootvp); |
139 | return (EINVAL); |
140 | } |
141 | |
142 | #ifdef UMAPFS_DIAGNOSTIC |
143 | printf("mp = %p\n" , mp); |
144 | #endif |
145 | |
146 | amp = kmem_zalloc(sizeof(struct umap_mount), KM_SLEEP); |
147 | mp->mnt_data = amp; |
148 | amp->umapm_vfs = lowerrootvp->v_mount; |
149 | if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) |
150 | mp->mnt_flag |= MNT_LOCAL; |
151 | |
152 | /* |
153 | * Now copy in the number of entries and maps for umap mapping. |
154 | */ |
155 | if (args->nentries < 0 || args->nentries > MAPFILEENTRIES || |
156 | args->gnentries < 0 || args->gnentries > GMAPFILEENTRIES) { |
157 | vput(lowerrootvp); |
158 | return (EINVAL); |
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_vnodeop_p = umap_vnodeop_p; |
201 | |
202 | /* |
203 | * fix up umap node for root vnode. |
204 | */ |
205 | VOP_UNLOCK(lowerrootvp); |
206 | error = layer_node_create(mp, lowerrootvp, &vp); |
207 | /* |
208 | * Make sure the node alias worked |
209 | */ |
210 | if (error) { |
211 | vrele(lowerrootvp); |
212 | kmem_free(amp, sizeof(struct umap_mount)); |
213 | return error; |
214 | } |
215 | |
216 | /* |
217 | * Keep a held reference to the root vnode. |
218 | * It is vrele'd in umapfs_unmount. |
219 | */ |
220 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
221 | vp->v_vflag |= VV_ROOT; |
222 | amp->umapm_rootvp = vp; |
223 | VOP_UNLOCK(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 | kmem_free(amp, sizeof(struct umap_mount)); |
268 | mp->mnt_data = NULL; |
269 | return 0; |
270 | } |
271 | |
272 | extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; |
273 | |
274 | const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { |
275 | &umapfs_vnodeop_opv_desc, |
276 | NULL, |
277 | }; |
278 | |
279 | struct vfsops umapfs_vfsops = { |
280 | .vfs_name = MOUNT_UMAP, |
281 | .vfs_min_mount_data = sizeof (struct umap_args), |
282 | .vfs_mount = umapfs_mount, |
283 | .vfs_start = layerfs_start, |
284 | .vfs_unmount = umapfs_unmount, |
285 | .vfs_root = layerfs_root, |
286 | .vfs_quotactl = layerfs_quotactl, |
287 | .vfs_statvfs = layerfs_statvfs, |
288 | .vfs_sync = layerfs_sync, |
289 | .vfs_loadvnode = layerfs_loadvnode, |
290 | .vfs_vget = layerfs_vget, |
291 | .vfs_fhtovp = layerfs_fhtovp, |
292 | .vfs_vptofh = layerfs_vptofh, |
293 | .vfs_init = layerfs_init, |
294 | .vfs_done = layerfs_done, |
295 | .vfs_snapshot = layerfs_snapshot, |
296 | .vfs_extattrctl = vfs_stdextattrctl, |
297 | .vfs_suspendctl = (void *)eopnotsupp, |
298 | .vfs_renamelock_enter = layerfs_renamelock_enter, |
299 | .vfs_renamelock_exit = layerfs_renamelock_exit, |
300 | .vfs_fsync = (void *)eopnotsupp, |
301 | .vfs_opv_descs = umapfs_vnodeopv_descs |
302 | }; |
303 | |
304 | static int |
305 | umap_modcmd(modcmd_t cmd, void *arg) |
306 | { |
307 | int error; |
308 | |
309 | switch (cmd) { |
310 | case MODULE_CMD_INIT: |
311 | error = vfs_attach(&umapfs_vfsops); |
312 | if (error != 0) |
313 | break; |
314 | sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, |
315 | CTLFLAG_PERMANENT, |
316 | CTLTYPE_NODE, "umap" , |
317 | SYSCTL_DESCR("UID/GID remapping file system" ), |
318 | NULL, 0, NULL, 0, |
319 | CTL_VFS, 10, CTL_EOL); |
320 | /* |
321 | * XXX the "10" above could be dynamic, thereby eliminating |
322 | * one more instance of the "number to vfs" mapping problem, |
323 | * but "10" is the order as taken from sys/mount.h |
324 | */ |
325 | break; |
326 | case MODULE_CMD_FINI: |
327 | error = vfs_detach(&umapfs_vfsops); |
328 | if (error != 0) |
329 | break; |
330 | sysctl_teardown(&umapfs_sysctl_log); |
331 | break; |
332 | default: |
333 | error = ENOTTY; |
334 | break; |
335 | } |
336 | |
337 | return (error); |
338 | } |
339 | |