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 * $FreeBSD$
29 */
30
31 #ifndef _PSEUDOFS_H_INCLUDED
32 #define _PSEUDOFS_H_INCLUDED
33
34 /*
35 * Opaque structures
36 */
37 struct mntarg;
38 struct mount;
39 struct nameidata;
40 struct proc;
41 struct sbuf;
42 struct statfs;
43 struct thread;
44 struct uio;
45 struct vfsconf;
46 struct vnode;
47
48 /*
49 * Limits and constants
50 */
51 #define PFS_NAMELEN 24
52 #define PFS_FSNAMELEN 16 /* equal to MFSNAMELEN */
53 #define PFS_DELEN (8 + PFS_NAMELEN)
54
55 typedef enum {
56 pfstype_none = 0,
57 pfstype_root,
58 pfstype_dir,
59 pfstype_this,
60 pfstype_parent,
61 pfstype_file,
62 pfstype_symlink,
63 pfstype_procdir
64 } pfs_type_t;
65
66 /*
67 * Flags
68 */
69 #define PFS_RD 0x0001 /* readable */
70 #define PFS_WR 0x0002 /* writeable */
71 #define PFS_RDWR (PFS_RD|PFS_WR)
72 #define PFS_RAWRD 0x0004 /* raw reader */
73 #define PFS_RAWWR 0x0008 /* raw writer */
74 #define PFS_RAW (PFS_RAWRD|PFS_RAWWR)
75 #define PFS_PROCDEP 0x0010 /* process-dependent */
76
77 /*
78 * Data structures
79 */
80 struct pfs_info;
81 struct pfs_node;
82 struct pfs_bitmap;
83
84 /*
85 * Init / uninit callback
86 */
87 #define PFS_INIT_ARGS \
88 struct pfs_info *pi, struct vfsconf *vfc
89 #define PFS_INIT_ARGNAMES \
90 pi, vfc
91 #define PFS_INIT_PROTO(name) \
92 int name(PFS_INIT_ARGS);
93 typedef int (*pfs_init_t)(PFS_INIT_ARGS);
94
95 /*
96 * Filler callback
97 * Called with proc held but unlocked
98 */
99 #define PFS_FILL_ARGS \
100 struct thread *td, struct proc *p, struct pfs_node *pn, \
101 struct sbuf *sb, struct uio *uio
102 #define PFS_FILL_ARGNAMES \
103 td, p, pn, sb, uio
104 #define PFS_FILL_PROTO(name) \
105 int name(PFS_FILL_ARGS);
106 typedef int (*pfs_fill_t)(PFS_FILL_ARGS);
107
108 /*
109 * Attribute callback
110 * Called with proc locked
111 */
112 struct vattr;
113 #define PFS_ATTR_ARGS \
114 struct thread *td, struct proc *p, struct pfs_node *pn, \
115 struct vattr *vap
116 #define PFS_ATTR_ARGNAMES \
117 td, p, pn, vap
118 #define PFS_ATTR_PROTO(name) \
119 int name(PFS_ATTR_ARGS);
120 typedef int (*pfs_attr_t)(PFS_ATTR_ARGS);
121
122 struct pfs_bitmap; /* opaque */
123
124 /*
125 * Visibility callback
126 * Called with proc locked
127 */
128 #define PFS_VIS_ARGS \
129 struct thread *td, struct proc *p, struct pfs_node *pn
130 #define PFS_VIS_ARGNAMES \
131 td, p, pn
132 #define PFS_VIS_PROTO(name) \
133 int name(PFS_VIS_ARGS);
134 typedef int (*pfs_vis_t)(PFS_VIS_ARGS);
135
136 /*
137 * Ioctl callback
138 * Called with proc locked
139 */
140 #define PFS_IOCTL_ARGS \
141 struct thread *td, struct proc *p, struct pfs_node *pn, \
142 unsigned long cmd, void *data
143 #define PFS_IOCTL_ARGNAMES \
144 td, p, pn, cmd, data
145 #define PFS_IOCTL_PROTO(name) \
146 int name(PFS_IOCTL_ARGS);
147 typedef int (*pfs_ioctl_t)(PFS_IOCTL_ARGS);
148
149 /*
150 * Getextattr callback
151 * Called with proc locked
152 */
153 #define PFS_GETEXTATTR_ARGS \
154 struct thread *td, struct proc *p, struct pfs_node *pn, \
155 int attrnamespace, const char *name, struct uio *uio, \
156 size_t *size, struct ucred *cred
157 #define PFS_GETEXTATTR_ARGNAMES \
158 td, p, pn, attrnamespace, name, uio, size, cred
159 #define PFS_GETEXTATTR_PROTO(name) \
160 int name(PFS_GETEXTATTR_ARGS);
161 struct ucred;
162 typedef int (*pfs_getextattr_t)(PFS_GETEXTATTR_ARGS);
163
164 /*
165 * Last-close callback
166 * Called with proc locked
167 */
168 #define PFS_CLOSE_ARGS \
169 struct thread *td, struct proc *p, struct pfs_node *pn
170 #define PFS_CLOSE_ARGNAMES \
171 td, p, pn
172 #define PFS_CLOSE_PROTO(name) \
173 int name(PFS_CLOSE_ARGS);
174 typedef int (*pfs_close_t)(PFS_CLOSE_ARGS);
175
176 /*
177 * Destroy callback
178 */
179 #define PFS_DESTROY_ARGS \
180 struct pfs_node *pn
181 #define PFS_DESTROY_ARGNAMES \
182 pn
183 #define PFS_DESTROY_PROTO(name) \
184 int name(PFS_DESTROY_ARGS);
185 typedef int (*pfs_destroy_t)(PFS_DESTROY_ARGS);
186
187 /*
188 * pfs_info: describes a pseudofs instance
189 *
190 * The pi_mutex is only used to avoid using the global subr_unit lock for
191 * unrhdr. The rest of struct pfs_info is only modified while Giant is
192 * held (during vfs_init() and vfs_uninit()).
193 */
194 struct pfs_info {
195 char pi_name[PFS_FSNAMELEN];
196 pfs_init_t pi_init;
197 pfs_init_t pi_uninit;
198
199 /* members below this line are initialized at run time*/
200 struct pfs_node *pi_root;
201 struct mtx pi_mutex;
202 struct unrhdr *pi_unrhdr;
203 };
204
205 /*
206 * pfs_node: describes a node (file or directory) within a pseudofs
207 *
208 * - Fields marked (o) are protected by the node's own mutex.
209 * - Fields marked (p) are protected by the node's parent's mutex.
210 * - Remaining fields are not protected by any lock and are assumed to be
211 * immutable once the node has been created.
212 *
213 * To prevent deadlocks, if a node's mutex is to be held at the same time
214 * as its parent's (e.g. when adding or removing nodes to a directory),
215 * the parent's mutex must always be acquired first. Unfortunately, this
216 * is not enforcable by WITNESS.
217 */
218 struct pfs_node {
219 char pn_name[PFS_NAMELEN];
220 pfs_type_t pn_type;
221 int pn_flags;
222 struct mtx pn_mutex;
223 void *pn_data; /* (o) */
224
225 pfs_fill_t pn_fill;
226 pfs_ioctl_t pn_ioctl;
227 pfs_close_t pn_close;
228 pfs_attr_t pn_attr;
229 pfs_vis_t pn_vis;
230 pfs_getextattr_t pn_getextattr;
231 pfs_destroy_t pn_destroy;
232
233 struct pfs_info *pn_info;
234 u_int32_t pn_fileno; /* (o) */
235
236 struct pfs_node *pn_parent; /* (o) */
237 struct pfs_node *pn_nodes; /* (o) */
238 struct pfs_node *pn_next; /* (p) */
239 };
240
241 /*
242 * VFS interface
243 */
244 int pfs_mount (struct pfs_info *pi, struct mount *mp,
245 struct thread *td);
246 int pfs_cmount (struct mntarg *ma, void *data, int flags,
247 struct thread *td);
248 int pfs_unmount (struct mount *mp, int mntflags,
249 struct thread *td);
250 int pfs_root (struct mount *mp, int flags,
251 struct vnode **vpp, struct thread *td);
252 int pfs_statfs (struct mount *mp, struct statfs *sbp,
253 struct thread *td);
254 int pfs_init (struct pfs_info *pi, struct vfsconf *vfc);
255 int pfs_uninit (struct pfs_info *pi, struct vfsconf *vfc);
256
257 /*
258 * Directory structure construction and manipulation
259 */
260 struct pfs_node *pfs_create_dir (struct pfs_node *parent, const char *name,
261 pfs_attr_t attr, pfs_vis_t vis,
262 pfs_destroy_t destroy, int flags);
263 struct pfs_node *pfs_create_file(struct pfs_node *parent, const char *name,
264 pfs_fill_t fill, pfs_attr_t attr,
265 pfs_vis_t vis, pfs_destroy_t destroy,
266 int flags);
267 struct pfs_node *pfs_create_link(struct pfs_node *parent, const char *name,
268 pfs_fill_t fill, pfs_attr_t attr,
269 pfs_vis_t vis, pfs_destroy_t destroy,
270 int flags);
271 struct pfs_node *pfs_find_node (struct pfs_node *parent, const char *name);
272 void pfs_purge (struct pfs_node *pn);
273 int pfs_destroy (struct pfs_node *pn);
274
275 /*
276 * Now for some initialization magic...
277 */
278 #define PSEUDOFS(name, version) \
279 \
280 static struct pfs_info name##_info = { \
281 #name, \
282 name##_init, \
283 name##_uninit, \
284 }; \
285 \
286 static int \
287 _##name##_mount(struct mount *mp, struct thread *td) { \
288 return pfs_mount(&name##_info, mp, td); \
289 } \
290 \
291 static int \
292 _##name##_init(struct vfsconf *vfc) { \
293 return pfs_init(&name##_info, vfc); \
294 } \
295 \
296 static int \
297 _##name##_uninit(struct vfsconf *vfc) { \
298 return pfs_uninit(&name##_info, vfc); \
299 } \
300 \
301 static struct vfsops name##_vfsops = { \
302 .vfs_cmount = pfs_cmount, \
303 .vfs_init = _##name##_init, \
304 .vfs_mount = _##name##_mount, \
305 .vfs_root = pfs_root, \
306 .vfs_statfs = pfs_statfs, \
307 .vfs_uninit = _##name##_uninit, \
308 .vfs_unmount = pfs_unmount, \
309 }; \
310 VFS_SET(name##_vfsops, name, VFCF_SYNTHETIC); \
311 MODULE_VERSION(name, version); \
312 MODULE_DEPEND(name, pseudofs, 1, 1, 1);
313
314 #endif
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