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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/6.0/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 */
49 void
50 pfs_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 */
64 void
65 pfs_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 */
82 void
83 pfs_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 */
134 void
135 pfs_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 }
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