pseudofs_fileno.c revision 143841 
1/*-
2 * Copyright (c) 2001 Dag-Erling Co�dan Sm�rgrav
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
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: head/sys/fs/pseudofs/pseudofs_fileno.c 143841 2005-03-19 08:22:36Z phk $");
31
32#include "opt_pseudofs.h"
33
34#include <sys/param.h>
35#include <sys/kernel.h>
36#include <sys/systm.h>
37#include <sys/limits.h>
38#include <sys/lock.h>
39#include <sys/malloc.h>
40#include <sys/mutex.h>
41#include <sys/sysctl.h>
42
43#include <fs/pseudofs/pseudofs.h>
44#include <fs/pseudofs/pseudofs_internal.h>
45
46/*
47 * Initialize fileno bitmap
48 */
49void
50pfs_fileno_init(struct pfs_info *pi)
51{
52	struct unrhdr *up;
53
54	up = new_unrhdr(3, INT_MAX, &pi->pi_mutex);
55	mtx_lock(&pi->pi_mutex);
56	pi->pi_unrhdr = up;
57	pi->pi_root->pn_fileno = 2;
58	mtx_unlock(&pi->pi_mutex);
59}
60
61/*
62 * Tear down fileno bitmap
63 */
64void
65pfs_fileno_uninit(struct pfs_info *pi)
66{
67	struct unrhdr *up;
68
69	mtx_lock(&pi->pi_mutex);
70
71	up = pi->pi_unrhdr;
72	pi->pi_unrhdr = NULL;
73
74	mtx_unlock(&pi->pi_mutex);
75
76	delete_unrhdr(up);
77}
78
79/*
80 * Allocate a file number
81 */
82void
83pfs_fileno_alloc(struct pfs_info *pi, struct pfs_node *pn)
84{
85	/* make sure our parent has a file number */
86	if (pn->pn_parent && !pn->pn_parent->pn_fileno)
87		pfs_fileno_alloc(pi, pn->pn_parent);
88
89	switch (pn->pn_type) {
90	case pfstype_root:
91	case pfstype_dir:
92	case pfstype_file:
93	case pfstype_symlink:
94	case pfstype_procdir:
95		pn->pn_fileno = alloc_unr(pi->pi_unrhdr);
96		break;
97	case pfstype_this:
98		KASSERT(pn->pn_parent != NULL,
99		    ("pfstype_this node has no parent"));
100		pn->pn_fileno = pn->pn_parent->pn_fileno;
101		break;
102	case pfstype_parent:
103		KASSERT(pn->pn_parent != NULL,
104		    ("pfstype_parent node has no parent"));
105		if (pn->pn_parent == pi->pi_root) {
106			pn->pn_fileno = pn->pn_parent->pn_fileno;
107			break;
108		}
109		KASSERT(pn->pn_parent->pn_parent != NULL,
110		    ("pfstype_parent node has no grandparent"));
111		pn->pn_fileno = pn->pn_parent->pn_parent->pn_fileno;
112		break;
113	case pfstype_none:
114		KASSERT(0,
115		    ("pfs_fileno_alloc() called for pfstype_none node"));
116		break;
117	}
118
119#if 0
120	printf("pfs_fileno_alloc(): %s: ", pi->pi_name);
121	if (pn->pn_parent) {
122		if (pn->pn_parent->pn_parent) {
123			printf("%s/", pn->pn_parent->pn_parent->pn_name);
124		}
125		printf("%s/", pn->pn_parent->pn_name);
126	}
127	printf("%s -> %d\n", pn->pn_name, pn->pn_fileno);
128#endif
129}
130
131/*
132 * Release a file number
133 */
134void
135pfs_fileno_free(struct pfs_info *pi, struct pfs_node *pn)
136{
137	switch (pn->pn_type) {
138	case pfstype_root:
139	case pfstype_dir:
140	case pfstype_file:
141	case pfstype_symlink:
142	case pfstype_procdir:
143		free_unr(pi->pi_unrhdr, pn->pn_fileno);
144		break;
145	case pfstype_this:
146	case pfstype_parent:
147		/* ignore these, as they don't "own" their file number */
148		break;
149	case pfstype_none:
150		KASSERT(0,
151		    ("pfs_fileno_free() called for pfstype_none node"));
152		break;
153	}
154}
155