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,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include "opt_pseudofs.h"
36 #include <sys/param.h>
37 #include <sys/kernel.h>
38 #include <sys/systm.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 #include <sys/mount.h>
43 #include <sys/mutex.h>
46 #include <sys/sysctl.h>
47 #include <sys/vnode.h>
49 #include <fs/pseudofs/pseudofs.h>
50 #include <fs/pseudofs/pseudofs_internal.h>
52 static MALLOC_DEFINE(M_PFSNODES, "pfs_nodes", "pseudofs nodes");
54 SYSCTL_NODE(_vfs, OID_AUTO, pfs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
59 SYSCTL_INT(_vfs_pfs, OID_AUTO, trace, CTLFLAG_RW, &pfs_trace, 0,
60 "enable tracing of pseudofs vnode operations");
63 #if PFS_FSNAMELEN != MFSNAMELEN
64 #error "PFS_FSNAMELEN is not equal to MFSNAMELEN"
68 * Allocate and initialize a node
70 static struct pfs_node *
71 pfs_alloc_node_flags(struct pfs_info *pi, const char *name, pfs_type_t type, int flags)
76 KASSERT(strlen(name) < PFS_NAMELEN,
77 ("%s(): node name is too long", __func__));
78 if (flags & PFS_NOWAIT)
79 malloc_flags = M_NOWAIT | M_ZERO;
81 malloc_flags = M_WAITOK | M_ZERO;
82 pn = malloc(sizeof *pn, M_PFSNODES, malloc_flags);
85 mtx_init(&pn->pn_mutex, "pfs_node", NULL, MTX_DEF | MTX_DUPOK);
86 strlcpy(pn->pn_name, name, sizeof pn->pn_name);
92 static struct pfs_node *
93 pfs_alloc_node(struct pfs_info *pi, const char *name, pfs_type_t type)
95 return (pfs_alloc_node_flags(pi, name, type, 0));
99 * Add a node to a directory
102 pfs_add_node(struct pfs_node *parent, struct pfs_node *pn)
105 struct pfs_node *iter;
108 KASSERT(parent != NULL,
109 ("%s(): parent is NULL", __func__));
110 KASSERT(pn->pn_parent == NULL,
111 ("%s(): node already has a parent", __func__));
112 KASSERT(parent->pn_info != NULL,
113 ("%s(): parent has no pn_info", __func__));
114 KASSERT(parent->pn_type == pfstype_dir ||
115 parent->pn_type == pfstype_procdir ||
116 parent->pn_type == pfstype_root,
117 ("%s(): parent is not a directory", __func__));
120 /* XXX no locking! */
121 if (pn->pn_type == pfstype_procdir)
122 for (iter = parent; iter != NULL; iter = iter->pn_parent)
123 KASSERT(iter->pn_type != pfstype_procdir,
124 ("%s(): nested process directories", __func__));
125 for (iter = parent->pn_nodes; iter != NULL; iter = iter->pn_next) {
126 KASSERT(strcmp(pn->pn_name, iter->pn_name) != 0,
127 ("%s(): homonymous siblings", __func__));
128 if (pn->pn_type == pfstype_procdir)
129 KASSERT(iter->pn_type != pfstype_procdir,
130 ("%s(): sibling process directories", __func__));
134 pn->pn_parent = parent;
135 pfs_fileno_alloc(pn);
138 if ((parent->pn_flags & PFS_PROCDEP) != 0)
139 pn->pn_flags |= PFS_PROCDEP;
140 if (parent->pn_nodes == NULL) {
141 KASSERT(parent->pn_last_node == NULL,
142 ("%s(): pn_last_node not NULL", __func__));
143 parent->pn_nodes = pn;
144 parent->pn_last_node = pn;
146 KASSERT(parent->pn_last_node != NULL,
147 ("%s(): pn_last_node is NULL", __func__));
148 KASSERT(parent->pn_last_node->pn_next == NULL,
149 ("%s(): pn_last_node->pn_next not NULL", __func__));
150 parent->pn_last_node->pn_next = pn;
151 parent->pn_last_node = pn;
157 * Detach a node from its aprent
160 pfs_detach_node(struct pfs_node *pn)
162 struct pfs_node *node, *parent = pn->pn_parent;
163 struct pfs_node **iter;
165 KASSERT(parent != NULL, ("%s(): node has no parent", __func__));
166 KASSERT(parent->pn_info == pn->pn_info,
167 ("%s(): parent has different pn_info", __func__));
170 if (pn == parent->pn_last_node) {
171 if (pn == pn->pn_nodes) {
172 parent->pn_last_node = NULL;
174 for (node = parent->pn_nodes;
175 node->pn_next != pn; node = node->pn_next)
177 parent->pn_last_node = node;
180 iter = &parent->pn_nodes;
181 while (*iter != NULL) {
186 iter = &(*iter)->pn_next;
188 pn->pn_parent = NULL;
193 * Add . and .. to a directory
196 pfs_fixup_dir_flags(struct pfs_node *parent, int flags)
198 struct pfs_node *dot, *dotdot;
200 dot = pfs_alloc_node_flags(parent->pn_info, ".", pfstype_this, flags);
203 dotdot = pfs_alloc_node_flags(parent->pn_info, "..", pfstype_parent, flags);
204 if (dotdot == NULL) {
208 pfs_add_node(parent, dot);
209 pfs_add_node(parent, dotdot);
214 pfs_fixup_dir(struct pfs_node *parent)
217 pfs_fixup_dir_flags(parent, 0);
224 pfs_create_dir(struct pfs_node *parent, const char *name,
225 pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
231 pn = pfs_alloc_node_flags(parent->pn_info, name,
232 (flags & PFS_PROCDEP) ? pfstype_procdir : pfstype_dir, flags);
237 pn->pn_destroy = destroy;
238 pn->pn_flags = flags;
239 pfs_add_node(parent, pn);
240 rc = pfs_fixup_dir_flags(pn, flags);
252 pfs_create_file(struct pfs_node *parent, const char *name, pfs_fill_t fill,
253 pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
258 pn = pfs_alloc_node_flags(parent->pn_info, name, pfstype_file, flags);
264 pn->pn_destroy = destroy;
265 pn->pn_flags = flags;
266 pfs_add_node(parent, pn);
275 pfs_create_link(struct pfs_node *parent, const char *name, pfs_fill_t fill,
276 pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
281 pn = pfs_alloc_node_flags(parent->pn_info, name, pfstype_symlink, flags);
287 pn->pn_destroy = destroy;
288 pn->pn_flags = flags;
289 pfs_add_node(parent, pn);
295 * Locate a node by name
298 pfs_find_node(struct pfs_node *parent, const char *name)
303 for (pn = parent->pn_nodes; pn != NULL; pn = pn->pn_next)
304 if (strcmp(pn->pn_name, name) == 0)
311 * Destroy a node and all its descendants. If the node to be destroyed
312 * has a parent, the parent's mutex must be held.
315 pfs_destroy(struct pfs_node *pn)
317 struct pfs_node *iter;
320 ("%s(): node is NULL", __func__));
321 KASSERT(pn->pn_info != NULL,
322 ("%s(): node has no pn_info", __func__));
327 /* destroy children */
328 if (pn->pn_type == pfstype_dir ||
329 pn->pn_type == pfstype_procdir ||
330 pn->pn_type == pfstype_root) {
332 while (pn->pn_nodes != NULL) {
334 pn->pn_nodes = iter->pn_next;
335 iter->pn_parent = NULL;
343 /* revoke vnodes and fileno */
346 /* callback to free any private resources */
347 if (pn->pn_destroy != NULL)
350 /* destroy the node */
352 mtx_destroy(&pn->pn_mutex);
353 free(pn, M_PFSNODES);
359 * Mount a pseudofs instance
362 pfs_mount(struct pfs_info *pi, struct mount *mp)
366 if (mp->mnt_flag & MNT_UPDATE)
370 mp->mnt_flag |= MNT_LOCAL;
371 mp->mnt_kern_flag |= MNTK_NOMSYNC;
377 vfs_mountedfrom(mp, pi->pi_name);
378 sbp->f_bsize = PAGE_SIZE;
379 sbp->f_iosize = PAGE_SIZE;
390 * Compatibility shim for old mount(2) system call
393 pfs_cmount(struct mntarg *ma, void *data, uint64_t flags)
397 error = kernel_mount(ma, flags);
402 * Unmount a pseudofs instance
405 pfs_unmount(struct mount *mp, int mntflags)
409 error = vflush(mp, 0, (mntflags & MNT_FORCE) ? FORCECLOSE : 0,
415 * Return a root vnode
418 pfs_root(struct mount *mp, int flags, struct vnode **vpp)
422 pi = (struct pfs_info *)mp->mnt_data;
423 return (pfs_vncache_alloc(mp, vpp, pi->pi_root, NO_PID));
427 * Return filesystem stats
430 pfs_statfs(struct mount *mp, struct statfs *sbp)
432 /* no-op: always called with mp->mnt_stat */
437 * Initialize a pseudofs instance
440 pfs_init(struct pfs_info *pi, struct vfsconf *vfc)
442 struct pfs_node *root;
447 /* set up the root directory */
448 root = pfs_alloc_node(pi, "/", pfstype_root);
450 pfs_fileno_alloc(root);
453 /* construct file hierarchy */
454 error = (pi->pi_init)(pi, vfc);
462 printf("%s registered\n", pi->pi_name);
467 * Destroy a pseudofs instance
470 pfs_uninit(struct pfs_info *pi, struct vfsconf *vfc)
474 pfs_destroy(pi->pi_root);
476 pfs_fileno_uninit(pi);
478 printf("%s unregistered\n", pi->pi_name);
479 error = (pi->pi_uninit)(pi, vfc);
484 * Handle load / unload events
487 pfs_modevent(module_t mod, int evt, void *arg)
495 pfs_vncache_unload();
507 static moduledata_t pseudofs_data = {
512 DECLARE_MODULE(pseudofs, pseudofs_data, SI_SUB_EXEC, SI_ORDER_FIRST);
513 MODULE_VERSION(pseudofs, 1);