1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 #include <sys/atomic.h>
26 #include <sys/cmn_err.h>
27 #include <sys/errno.h>
28 #include <sys/mount.h>
29 #include <sys/objfs.h>
30 #include <sys/objfs_impl.h>
31 #include <sys/vfs_opreg.h>
32 #include <sys/policy.h>
33 #include <sys/sunddi.h>
34 #include <sys/sysmacros.h>
35 #include <sys/systm.h>
36
37 /*
38 * Kernel object filesystem.
39 *
40 * This is a pseudo filesystem which exports information about currently loaded
41 * kernel objects. The root directory contains one directory for each loaded
42 * object, indexed by module name. Within each object directory is an ELF file,
43 * 'object', that contains information about the currently loaded module.
44 *
45 * This file contains functions that interact with the VFS layer. Each
46 * filesystem element is represented by a a different node.
47 *
48 * / objfs_rootnode_t objfs_root.c
49 * /<obj> objfs_odirnode_t objfs_odir.c
50 * /<obj>/object objfs_datanode_t objfs_data.c
51 *
52 * In addition, some common routines are found in the 'objfs_common.c' file.
53 */
54
55 vnodeops_t *objfs_ops_root;
56 vnodeops_t *objfs_ops_odir;
57 vnodeops_t *objfs_ops_data;
58
59 static const fs_operation_def_t objfs_vfstops[];
60 static gfs_opsvec_t objfs_opsvec[];
61
62 static int objfs_init(int, char *);
63
64 /*
65 * Module linkage
66 */
67 static mntopts_t objfs_mntopts = {
68 0,
69 NULL
70 };
71
72 static vfsdef_t vfw = {
73 VFSDEF_VERSION,
74 "objfs",
75 objfs_init,
76 VSW_HASPROTO | VSW_ZMOUNT,
77 &objfs_mntopts,
78 };
79
80 extern struct mod_ops mod_fsops;
81
82 static struct modlfs modlfs = {
83 &mod_fsops, "kernel object filesystem", &vfw
84 };
85
86 static struct modlinkage modlinkage = {
87 MODREV_1, (void *)&modlfs, NULL
88 };
89
90 int
91 _init(void)
92 {
93 return (mod_install(&modlinkage));
94 }
95
96 int
97 _info(struct modinfo *modinfop)
98 {
99 return (mod_info(&modlinkage, modinfop));
100 }
101
102 int
103 _fini(void)
104 {
105 /*
106 * The object filesystem cannot be unloaded.
107 */
108 return (EBUSY);
109 }
110
111 /*
112 * Filesystem initialization.
113 */
114
115 static int objfs_fstype;
116 static major_t objfs_major;
117 static minor_t objfs_minor;
118
119 static gfs_opsvec_t objfs_opsvec[] = {
120 { "objfs root directory", objfs_tops_root, &objfs_ops_root },
121 { "objfs object directory", objfs_tops_odir, &objfs_ops_odir },
122 { "objfs data file", objfs_tops_data, &objfs_ops_data },
123 { NULL }
124 };
125
126 /* ARGSUSED */
127 static int
128 objfs_init(int fstype, char *name)
129 {
130 vfsops_t *vfsops;
131 int error;
132
133 objfs_fstype = fstype;
134 if (error = vfs_setfsops(fstype, objfs_vfstops, &vfsops)) {
135 cmn_err(CE_WARN, "objfs_init: bad vfs ops template");
136 return (error);
137 }
138
139 if (error = gfs_make_opsvec(objfs_opsvec)) {
140 (void) vfs_freevfsops(vfsops);
141 return (error);
142 }
143
144 if ((objfs_major = getudev()) == (major_t)-1) {
145 cmn_err(CE_WARN, "objfs_init: can't get unique device number");
146 objfs_major = 0;
147 }
148
149 objfs_data_init();
150
151 return (0);
152 }
153
154 /*
155 * VFS entry points
156 */
157 static int
158 objfs_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr)
159 {
160 objfs_vfs_t *data;
161 dev_t dev;
162
163 if (secpolicy_fs_mount(cr, mvp, vfsp) != 0)
164 return (EPERM);
165
166 if (mvp->v_type != VDIR)
167 return (ENOTDIR);
168
169 if ((uap->flags & MS_OVERLAY) == 0 &&
170 (mvp->v_count > 1 || (mvp->v_flag & VROOT)))
171 return (EBUSY);
172
173 data = kmem_alloc(sizeof (objfs_vfs_t), KM_SLEEP);
174
175 /*
176 * Initialize vfs fields
177 */
178 vfsp->vfs_bsize = DEV_BSIZE;
179 vfsp->vfs_fstype = objfs_fstype;
180 do {
181 dev = makedevice(objfs_major,
182 atomic_inc_32_nv(&objfs_minor) & L_MAXMIN32);
183 } while (vfs_devismounted(dev));
184 vfs_make_fsid(&vfsp->vfs_fsid, dev, objfs_fstype);
185 vfsp->vfs_data = data;
186 vfsp->vfs_dev = dev;
187
188 /*
189 * Create root
190 */
191 data->objfs_vfs_root = objfs_create_root(vfsp);
192
193 return (0);
194 }
195
196 static int
197 objfs_unmount(vfs_t *vfsp, int flag, struct cred *cr)
198 {
199 objfs_vfs_t *data;
200
201 if (secpolicy_fs_unmount(cr, vfsp) != 0)
202 return (EPERM);
203
204 /*
205 * We do not currently support forced unmounts
206 */
207 if (flag & MS_FORCE)
208 return (ENOTSUP);
209
210 /*
211 * We should never have a reference count of less than 2: one for the
212 * caller, one for the root vnode.
213 */
214 ASSERT(vfsp->vfs_count >= 2);
215
216 /*
217 * Any active vnodes will result in a hold on the root vnode
218 */
219 data = vfsp->vfs_data;
220 if (data->objfs_vfs_root->v_count > 1)
221 return (EBUSY);
222
223 /*
224 * Release the last hold on the root vnode
225 */
226 VN_RELE(data->objfs_vfs_root);
227
228 kmem_free(data, sizeof (objfs_vfs_t));
229
230 return (0);
231 }
232
233 static int
234 objfs_root(vfs_t *vfsp, vnode_t **vpp)
235 {
236 objfs_vfs_t *data = vfsp->vfs_data;
237
238 *vpp = data->objfs_vfs_root;
239 VN_HOLD(*vpp);
240
241 return (0);
242 }
243
244 static int
245 objfs_statvfs(vfs_t *vfsp, statvfs64_t *sp)
246 {
247 dev32_t d32;
248 int total = objfs_nobjs();
249
250 bzero(sp, sizeof (*sp));
251 sp->f_bsize = DEV_BSIZE;
252 sp->f_frsize = DEV_BSIZE;
253 sp->f_files = total;
254 sp->f_ffree = sp->f_favail = INT_MAX - total;
255 (void) cmpldev(&d32, vfsp->vfs_dev);
256 sp->f_fsid = d32;
257 (void) strlcpy(sp->f_basetype, vfssw[vfsp->vfs_fstype].vsw_name,
258 sizeof (sp->f_basetype));
259 sp->f_flag = vf_to_stf(vfsp->vfs_flag);
260 sp->f_namemax = OBJFS_NAME_MAX;
261 (void) strlcpy(sp->f_fstr, "object", sizeof (sp->f_fstr));
262
263 return (0);
264 }
265
266 static const fs_operation_def_t objfs_vfstops[] = {
267 { VFSNAME_MOUNT, { .vfs_mount = objfs_mount } },
268 { VFSNAME_UNMOUNT, { .vfs_unmount = objfs_unmount } },
269 { VFSNAME_ROOT, { .vfs_root = objfs_root } },
270 { VFSNAME_STATVFS, { .vfs_statvfs = objfs_statvfs } },
271 { NULL }
272 };