1 /*-
2 * Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: releng/5.0/sys/fs/pseudofs/pseudofs.c 103314 2002-09-14 09:02:28Z njl $
29 */
30
31 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/systm.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/mount.h>
38 #include <sys/mutex.h>
39 #include <sys/proc.h>
40 #include <sys/sbuf.h>
41 #include <sys/sysctl.h>
42 #include <sys/vnode.h>
43
44 #include <fs/pseudofs/pseudofs.h>
45 #include <fs/pseudofs/pseudofs_internal.h>
46
47 static MALLOC_DEFINE(M_PFSNODES, "pfs_nodes", "pseudofs nodes");
48
49 SYSCTL_NODE(_vfs, OID_AUTO, pfs, CTLFLAG_RW, 0,
50 "pseudofs");
51
52 #if PFS_FSNAMELEN != MFSNAMELEN
53 #error "PFS_FSNAMELEN is not equal to MFSNAMELEN"
54 #endif
55
56 /*
57 * Add a node to a directory
58 */
59 static int
60 _pfs_add_node(struct pfs_node *parent, struct pfs_node *node)
61 {
62 KASSERT(parent != NULL,
63 ("%s(): parent is NULL", __func__));
64 KASSERT(parent->pn_info != NULL,
65 ("%s(): parent has no pn_info", __func__));
66 KASSERT(parent->pn_type == pfstype_dir ||
67 parent->pn_type == pfstype_procdir ||
68 parent->pn_type == pfstype_root,
69 ("%s(): parent is not a directory", __func__));
70
71 /* XXX should check for duplicate names etc. */
72
73 mtx_lock(&parent->pn_info->pi_mutex);
74 node->pn_info = parent->pn_info;
75 node->pn_parent = parent;
76 node->pn_next = parent->pn_nodes;
77 parent->pn_nodes = node;
78 /* Propagate flag to all child nodes (and thus their vnodes) */
79 if ((parent->pn_flags & PFS_PROCDEP) != 0)
80 node->pn_flags |= PFS_PROCDEP;
81 mtx_unlock(&parent->pn_info->pi_mutex);
82
83 return (0);
84 }
85
86 /*
87 * Add . and .. to a directory
88 */
89 static int
90 _pfs_fixup_dir(struct pfs_node *parent)
91 {
92 struct pfs_node *dir;
93
94 MALLOC(dir, struct pfs_node *, sizeof *dir,
95 M_PFSNODES, M_WAITOK|M_ZERO);
96 dir->pn_name[0] = '.';
97 dir->pn_type = pfstype_this;
98
99 if (_pfs_add_node(parent, dir) != 0) {
100 FREE(dir, M_PFSNODES);
101 return (-1);
102 }
103
104 MALLOC(dir, struct pfs_node *, sizeof *dir,
105 M_PFSNODES, M_WAITOK|M_ZERO);
106 dir->pn_name[0] = dir->pn_name[1] = '.';
107 dir->pn_type = pfstype_parent;
108
109 if (_pfs_add_node(parent, dir) != 0) {
110 FREE(dir, M_PFSNODES);
111 return (-1);
112 }
113
114 return (0);
115 }
116
117 /*
118 * Create a directory
119 */
120 struct pfs_node *
121 pfs_create_dir(struct pfs_node *parent, char *name,
122 pfs_attr_t attr, pfs_vis_t vis, int flags)
123 {
124 struct pfs_node *dir;
125
126 KASSERT(strlen(name) < PFS_NAMELEN,
127 ("%s(): node name is too long", __func__));
128
129 MALLOC(dir, struct pfs_node *, sizeof *dir,
130 M_PFSNODES, M_WAITOK|M_ZERO);
131 strcpy(dir->pn_name, name);
132 dir->pn_type = (flags & PFS_PROCDEP) ? pfstype_procdir : pfstype_dir;
133 dir->pn_attr = attr;
134 dir->pn_vis = vis;
135 dir->pn_flags = flags;
136
137 if (_pfs_add_node(parent, dir) != 0) {
138 FREE(dir, M_PFSNODES);
139 return (NULL);
140 }
141
142 if (_pfs_fixup_dir(dir) != 0) {
143 pfs_destroy(dir);
144 return (NULL);
145 }
146
147 return (dir);
148 }
149
150 /*
151 * Create a file
152 */
153 struct pfs_node *
154 pfs_create_file(struct pfs_node *parent, char *name, pfs_fill_t fill,
155 pfs_attr_t attr, pfs_vis_t vis, int flags)
156 {
157 struct pfs_node *node;
158
159 KASSERT(strlen(name) < PFS_NAMELEN,
160 ("%s(): node name is too long", __func__));
161
162 MALLOC(node, struct pfs_node *, sizeof *node,
163 M_PFSNODES, M_WAITOK|M_ZERO);
164 strcpy(node->pn_name, name);
165 node->pn_type = pfstype_file;
166 node->pn_func = fill;
167 node->pn_attr = attr;
168 node->pn_vis = vis;
169 node->pn_flags = flags;
170
171 if (_pfs_add_node(parent, node) != 0) {
172 FREE(node, M_PFSNODES);
173 return (NULL);
174 }
175
176 return (node);
177 }
178
179 /*
180 * Create a symlink
181 */
182 struct pfs_node *
183 pfs_create_link(struct pfs_node *parent, char *name, pfs_fill_t fill,
184 pfs_attr_t attr, pfs_vis_t vis, int flags)
185 {
186 struct pfs_node *node;
187
188 node = pfs_create_file(parent, name, fill, attr, vis, flags);
189 if (node == NULL)
190 return (NULL);
191 node->pn_type = pfstype_symlink;
192 return (node);
193 }
194
195 /*
196 * Destroy a node or a tree of nodes
197 */
198 int
199 pfs_destroy(struct pfs_node *node)
200 {
201 struct pfs_node *parent, *rover;
202
203 KASSERT(node != NULL,
204 ("%s(): node is NULL", __func__));
205 KASSERT(node->pn_info != NULL,
206 ("%s(): node has no pn_info", __func__));
207
208 /* destroy children */
209 if (node->pn_type == pfstype_dir ||
210 node->pn_type == pfstype_procdir ||
211 node->pn_type == pfstype_root)
212 while (node->pn_nodes != NULL)
213 pfs_destroy(node->pn_nodes);
214
215 /* unlink from parent */
216 if ((parent = node->pn_parent) != NULL) {
217 KASSERT(parent->pn_info == node->pn_info,
218 ("%s(): parent has different pn_info", __func__));
219 mtx_lock(&node->pn_info->pi_mutex);
220 if (parent->pn_nodes == node) {
221 parent->pn_nodes = node->pn_next;
222 } else {
223 rover = parent->pn_nodes;
224 while (rover->pn_next != NULL) {
225 if (rover->pn_next == node) {
226 rover->pn_next = node->pn_next;
227 break;
228 }
229 rover = rover->pn_next;
230 }
231 }
232 mtx_unlock(&node->pn_info->pi_mutex);
233 }
234
235 /* revoke vnodes and release memory */
236 pfs_disable(node);
237 FREE(node, M_PFSNODES);
238
239 return (0);
240 }
241
242 /*
243 * Mount a pseudofs instance
244 */
245 int
246 pfs_mount(struct pfs_info *pi, struct mount *mp, struct nameidata *ndp,
247 struct thread *td)
248 {
249 struct statfs *sbp;
250
251 if (mp->mnt_flag & MNT_UPDATE)
252 return (EOPNOTSUPP);
253
254 mp->mnt_flag |= MNT_LOCAL;
255 mp->mnt_data = (qaddr_t)pi;
256 vfs_getnewfsid(mp);
257
258 sbp = &mp->mnt_stat;
259 bcopy(pi->pi_name, sbp->f_mntfromname, sizeof pi->pi_name);
260 sbp->f_bsize = PAGE_SIZE;
261 sbp->f_iosize = PAGE_SIZE;
262 sbp->f_blocks = 1;
263 sbp->f_bfree = 0;
264 sbp->f_bavail = 0;
265 sbp->f_files = 1;
266 sbp->f_ffree = 0;
267
268 return (0);
269 }
270
271 /*
272 * Unmount a pseudofs instance
273 */
274 int
275 pfs_unmount(struct mount *mp, int mntflags, struct thread *td)
276 {
277 struct pfs_info *pi;
278 int error;
279
280 pi = (struct pfs_info *)mp->mnt_data;
281
282 /* XXX do stuff with pi... */
283
284 error = vflush(mp, 0, (mntflags & MNT_FORCE) ? FORCECLOSE : 0);
285 return (error);
286 }
287
288 /*
289 * Return a root vnode
290 */
291 int
292 pfs_root(struct mount *mp, struct vnode **vpp)
293 {
294 struct pfs_info *pi;
295
296 pi = (struct pfs_info *)mp->mnt_data;
297 return pfs_vncache_alloc(mp, vpp, pi->pi_root, NO_PID);
298 }
299
300 /*
301 * Return filesystem stats
302 */
303 int
304 pfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
305 {
306 bcopy(&mp->mnt_stat, sbp, sizeof *sbp);
307 return (0);
308 }
309
310 /*
311 * Initialize a pseudofs instance
312 */
313 int
314 pfs_init(struct pfs_info *pi, struct vfsconf *vfc)
315 {
316 struct pfs_node *root;
317 int error;
318
319 mtx_init(&pi->pi_mutex, "pseudofs", NULL, MTX_DEF);
320
321 /* set up the root diretory */
322 MALLOC(root, struct pfs_node *, sizeof *root,
323 M_PFSNODES, M_WAITOK|M_ZERO);
324 root->pn_type = pfstype_root;
325 root->pn_name[0] = '/';
326 root->pn_info = pi;
327 if (_pfs_fixup_dir(root) != 0) {
328 FREE(root, M_PFSNODES);
329 return (ENODEV); /* XXX not really the right errno */
330 }
331 pi->pi_root = root;
332
333 /* construct file hierarchy */
334 error = (pi->pi_init)(pi, vfc);
335 if (error) {
336 pfs_destroy(root);
337 pi->pi_root = NULL;
338 mtx_destroy(&pi->pi_mutex);
339 return (error);
340 }
341
342 pfs_fileno_init(pi);
343 if (bootverbose)
344 printf("%s registered\n", pi->pi_name);
345 return (0);
346 }
347
348 /*
349 * Destroy a pseudofs instance
350 */
351 int
352 pfs_uninit(struct pfs_info *pi, struct vfsconf *vfc)
353 {
354 int error;
355
356 pfs_fileno_uninit(pi);
357 pfs_destroy(pi->pi_root);
358 pi->pi_root = NULL;
359 mtx_destroy(&pi->pi_mutex);
360 if (bootverbose)
361 printf("%s unregistered\n", pi->pi_name);
362 error = (pi->pi_uninit)(pi, vfc);
363 return (error);
364 }
365
366 /*
367 * Handle load / unload events
368 */
369 static int
370 pfs_modevent(module_t mod, int evt, void *arg)
371 {
372 switch (evt) {
373 case MOD_LOAD:
374 pfs_fileno_load();
375 pfs_vncache_load();
376 break;
377 case MOD_UNLOAD:
378 case MOD_SHUTDOWN:
379 pfs_vncache_unload();
380 pfs_fileno_unload();
381 break;
382 default:
383 printf("pseudofs: unexpected event type %d\n", evt);
384 break;
385 }
386 return 0;
387 }
388
389 /*
390 * Module declaration
391 */
392 static moduledata_t pseudofs_data = {
393 "pseudofs",
394 pfs_modevent,
395 NULL
396 };
397 DECLARE_MODULE(pseudofs, pseudofs_data, SI_SUB_EXEC, SI_ORDER_FIRST);
398 MODULE_VERSION(pseudofs, 1);
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