2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer
12 * in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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33 #ifndef _PSEUDOFS_H_INCLUDED
34 #define _PSEUDOFS_H_INCLUDED
53 * Limits and constants
55 #define PFS_NAMELEN 48
56 #define PFS_FSNAMELEN 16 /* equal to MFSNAMELEN */
57 #define PFS_DELEN (offsetof(struct dirent, d_name) + PFS_NAMELEN)
73 #define PFS_RD 0x0001 /* readable */
74 #define PFS_WR 0x0002 /* writeable */
75 #define PFS_RDWR (PFS_RD|PFS_WR)
76 #define PFS_RAWRD 0x0004 /* raw reader */
77 #define PFS_RAWWR 0x0008 /* raw writer */
78 #define PFS_RAW (PFS_RAWRD|PFS_RAWWR)
79 #define PFS_PROCDEP 0x0010 /* process-dependent */
88 * Init / uninit callback
90 #define PFS_INIT_ARGS \
91 struct pfs_info *pi, struct vfsconf *vfc
92 #define PFS_INIT_ARGNAMES \
94 #define PFS_INIT_PROTO(name) \
95 int name(PFS_INIT_ARGS);
96 typedef int (*pfs_init_t)(PFS_INIT_ARGS);
100 * Called with proc held but unlocked
102 #define PFS_FILL_ARGS \
103 struct thread *td, struct proc *p, struct pfs_node *pn, \
104 struct sbuf *sb, struct uio *uio
105 #define PFS_FILL_ARGNAMES \
107 #define PFS_FILL_PROTO(name) \
108 int name(PFS_FILL_ARGS);
109 typedef int (*pfs_fill_t)(PFS_FILL_ARGS);
113 * Called with proc locked
116 #define PFS_ATTR_ARGS \
117 struct thread *td, struct proc *p, struct pfs_node *pn, \
119 #define PFS_ATTR_ARGNAMES \
121 #define PFS_ATTR_PROTO(name) \
122 int name(PFS_ATTR_ARGS);
123 typedef int (*pfs_attr_t)(PFS_ATTR_ARGS);
126 * Visibility callback
127 * Called with proc locked
129 #define PFS_VIS_ARGS \
130 struct thread *td, struct proc *p, struct pfs_node *pn
131 #define PFS_VIS_ARGNAMES \
133 #define PFS_VIS_PROTO(name) \
134 int name(PFS_VIS_ARGS);
135 typedef int (*pfs_vis_t)(PFS_VIS_ARGS);
139 * Called with proc locked
141 #define PFS_IOCTL_ARGS \
142 struct thread *td, struct proc *p, struct pfs_node *pn, \
143 unsigned long cmd, void *data
144 #define PFS_IOCTL_ARGNAMES \
146 #define PFS_IOCTL_PROTO(name) \
147 int name(PFS_IOCTL_ARGS);
148 typedef int (*pfs_ioctl_t)(PFS_IOCTL_ARGS);
151 * Getextattr callback
152 * Called with proc locked
154 #define PFS_GETEXTATTR_ARGS \
155 struct thread *td, struct proc *p, struct pfs_node *pn, \
156 int attrnamespace, const char *name, struct uio *uio, \
157 size_t *size, struct ucred *cred
158 #define PFS_GETEXTATTR_ARGNAMES \
159 td, p, pn, attrnamespace, name, uio, size, cred
160 #define PFS_GETEXTATTR_PROTO(name) \
161 int name(PFS_GETEXTATTR_ARGS);
163 typedef int (*pfs_getextattr_t)(PFS_GETEXTATTR_ARGS);
166 * Last-close callback
167 * Called with proc locked
169 #define PFS_CLOSE_ARGS \
170 struct thread *td, struct proc *p, struct pfs_node *pn
171 #define PFS_CLOSE_ARGNAMES \
173 #define PFS_CLOSE_PROTO(name) \
174 int name(PFS_CLOSE_ARGS);
175 typedef int (*pfs_close_t)(PFS_CLOSE_ARGS);
180 #define PFS_DESTROY_ARGS \
182 #define PFS_DESTROY_ARGNAMES \
184 #define PFS_DESTROY_PROTO(name) \
185 int name(PFS_DESTROY_ARGS);
186 typedef int (*pfs_destroy_t)(PFS_DESTROY_ARGS);
189 * pfs_info: describes a pseudofs instance
191 * The pi_mutex is only used to avoid using the global subr_unit lock
192 * for unrhdr. The rest of struct pfs_info is only modified during
193 * vfs_init() and vfs_uninit() of the consumer filesystem.
196 char pi_name[PFS_FSNAMELEN];
198 pfs_init_t pi_uninit;
200 /* members below this line are initialized at run time */
201 struct pfs_node *pi_root;
203 struct unrhdr *pi_unrhdr;
207 * pfs_node: describes a node (file or directory) within a pseudofs
209 * - Fields marked (o) are protected by the node's own mutex.
210 * - Fields marked (p) are protected by the node's parent's mutex.
211 * - Remaining fields are not protected by any lock and are assumed to be
212 * immutable once the node has been created.
214 * To prevent deadlocks, if a node's mutex is to be held at the same time
215 * as its parent's (e.g. when adding or removing nodes to a directory),
216 * the parent's mutex must always be acquired first. Unfortunately, this
217 * is not enforcable by WITNESS.
220 char pn_name[PFS_NAMELEN];
224 void *pn_data; /* (o) */
227 pfs_ioctl_t pn_ioctl;
228 pfs_close_t pn_close;
231 pfs_getextattr_t pn_getextattr;
232 pfs_destroy_t pn_destroy;
234 struct pfs_info *pn_info;
235 u_int32_t pn_fileno; /* (o) */
237 struct pfs_node *pn_parent; /* (o) */
238 struct pfs_node *pn_nodes; /* (o) */
239 struct pfs_node *pn_next; /* (p) */
245 int pfs_mount (struct pfs_info *pi, struct mount *mp);
246 int pfs_cmount (struct mntarg *ma, void *data, uint64_t flags);
247 int pfs_unmount (struct mount *mp, int mntflags);
248 int pfs_root (struct mount *mp, int flags,
250 int pfs_statfs (struct mount *mp, struct statfs *sbp);
251 int pfs_init (struct pfs_info *pi, struct vfsconf *vfc);
252 int pfs_uninit (struct pfs_info *pi, struct vfsconf *vfc);
255 * Directory structure construction and manipulation
257 struct pfs_node *pfs_create_dir (struct pfs_node *parent, const char *name,
258 pfs_attr_t attr, pfs_vis_t vis,
259 pfs_destroy_t destroy, int flags);
260 struct pfs_node *pfs_create_file(struct pfs_node *parent, const char *name,
261 pfs_fill_t fill, pfs_attr_t attr,
262 pfs_vis_t vis, pfs_destroy_t destroy,
264 struct pfs_node *pfs_create_link(struct pfs_node *parent, const char *name,
265 pfs_fill_t fill, pfs_attr_t attr,
266 pfs_vis_t vis, pfs_destroy_t destroy,
268 struct pfs_node *pfs_find_node (struct pfs_node *parent, const char *name);
269 void pfs_purge (struct pfs_node *pn);
270 int pfs_destroy (struct pfs_node *pn);
273 * Now for some initialization magic...
275 #define PSEUDOFS(name, version, jflag) \
277 static struct pfs_info name##_info = { \
284 _##name##_mount(struct mount *mp) { \
285 if (jflag && !prison_allow(curthread->td_ucred, jflag)) \
287 return (pfs_mount(&name##_info, mp)); \
291 _##name##_init(struct vfsconf *vfc) { \
292 return (pfs_init(&name##_info, vfc)); \
296 _##name##_uninit(struct vfsconf *vfc) { \
297 return (pfs_uninit(&name##_info, vfc)); \
300 static struct vfsops name##_vfsops = { \
301 .vfs_cmount = pfs_cmount, \
302 .vfs_init = _##name##_init, \
303 .vfs_mount = _##name##_mount, \
304 .vfs_root = pfs_root, \
305 .vfs_statfs = pfs_statfs, \
306 .vfs_uninit = _##name##_uninit, \
307 .vfs_unmount = pfs_unmount, \
309 VFS_SET(name##_vfsops, name, VFCF_SYNTHETIC | (jflag ? VFCF_JAIL : 0)); \
310 MODULE_VERSION(name, version); \
311 MODULE_DEPEND(name, pseudofs, 1, 1, 1);