xref: /freebsd/sys/fs/devfs/devfs_devs.c (revision db901281608f0c69c05dd9ab366155d3225f0fd2)
1 #define DEBUG 1
2 /*
3  * Copyright (c) 2000
4  *	Poul-Henning Kamp.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Neither the name of the University nor the names of its contributors
12  *    may be used to endorse or promote products derived from this software
13  *    without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
28  *
29  * $FreeBSD$
30  */
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/dirent.h>
35 #include <sys/conf.h>
36 #include <sys/vnode.h>
37 #include <sys/malloc.h>
38 #include <sys/eventhandler.h>
39 #include <sys/ctype.h>
40 
41 #define DEVFS_INTERN
42 #include <fs/devfs/devfs.h>
43 
44 struct devfs_dirent *
45 devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
46 {
47 	struct devfs_dirent *de;
48 
49 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
50 		if (namelen != de->de_dirent->d_namlen)
51 			continue;
52 		if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
53 			continue;
54 		break;
55 	}
56 	return (de);
57 }
58 
59 struct devfs_dirent *
60 devfs_newdirent(char *name, int namelen)
61 {
62 	int i;
63 	struct devfs_dirent *de;
64 	struct dirent d;
65 
66 	d.d_namlen = namelen;
67 	i = sizeof (*de) + GENERIC_DIRSIZ(&d);
68 	MALLOC(de, struct devfs_dirent *, i, M_DEVFS, M_WAITOK);
69 	bzero(de, i);
70 	de->de_dirent = (struct dirent *)(de + 1);
71 	de->de_dirent->d_namlen = namelen;
72 	de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
73 	bcopy(name, de->de_dirent->d_name, namelen + 1);
74 	nanotime(&de->de_ctime);
75 	de->de_mtime = de->de_atime = de->de_ctime;
76 	de->de_links = 1;
77 	return (de);
78 }
79 
80 struct devfs_dirent *
81 devfs_vmkdir(char *name, int namelen, struct devfs_dirent *dotdot)
82 {
83 	struct devfs_dirent *dd;
84 	struct devfs_dirent *de;
85 
86 	dd = devfs_newdirent(name, namelen);
87 
88 	TAILQ_INIT(&dd->de_dlist);
89 
90 	dd->de_dirent->d_type = DT_DIR;
91 	dd->de_mode = 0755;
92 	dd->de_links = 2;
93 	dd->de_dir = dd;
94 
95 	de = devfs_newdirent(".", 1);
96 	de->de_dirent->d_type = DT_DIR;
97 	de->de_dir = dd;
98 	de->de_flags |= DE_DOT;
99 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
100 
101 	de = devfs_newdirent("..", 2);
102 	de->de_dirent->d_type = DT_DIR;
103 	if (dotdot == NULL)
104 		de->de_dir = dd;
105 	else
106 		de->de_dir = dotdot;
107 	de->de_flags |= DE_DOTDOT;
108 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
109 
110 	return (dd);
111 }
112 
113 static void
114 devfs_delete(struct devfs_dirent *dd, struct devfs_dirent *de)
115 {
116 
117 	if (de->de_symlink) {
118 		FREE(de->de_symlink, M_DEVFS);
119 		de->de_symlink = NULL;
120 	}
121 	if (de->de_vnode) {
122 		de->de_vnode->v_data = NULL;
123 		vdrop(de->de_vnode);
124 	}
125 	TAILQ_REMOVE(&dd->de_dlist, de, de_list);
126 	FREE(de, M_DEVFS);
127 }
128 
129 void
130 devfs_purge(struct devfs_dirent *dd)
131 {
132 	struct devfs_dirent *de;
133 
134 	for (;;) {
135 		de = TAILQ_FIRST(&dd->de_dlist);
136 		if (de == NULL)
137 			break;
138 		devfs_delete(dd, de);
139 	}
140 	FREE(dd, M_DEVFS);
141 }
142 
143 
144 int
145 devfs_populate(struct devfs_mount *dm)
146 {
147 	int i, j;
148 	dev_t dev, pdev;
149 	struct devfs_dirent *dd;
150 	struct devfs_dirent *de;
151 	char *q, *s;
152 
153 	while (dm->dm_generation != devfs_generation) {
154 		dm->dm_generation = devfs_generation;
155 		for (i = 0; i < NDEVINO; i++) {
156 			dev = devfs_inot[i];
157 			de = dm->dm_dirent[i];
158 			if (dev == NULL && de == DE_DELETED) {
159 				dm->dm_dirent[i] = NULL;
160 				continue;
161 			}
162 			if (dev == NULL && de != NULL) {
163 				dd = de->de_dir;
164 				dm->dm_dirent[i] = NULL;
165 				TAILQ_REMOVE(&dd->de_dlist, de, de_list);
166 				if (de->de_vnode) {
167 					de->de_vnode->v_data = NULL;
168 					vdrop(de->de_vnode);
169 				}
170 				FREE(de, M_DEVFS);
171 				continue;
172 			}
173 			if (dev == NULL)
174 				continue;
175 			if (de != NULL)
176 				continue;
177 			dd = dm->dm_basedir;
178 			s = dev->si_name;
179 			for (;;) {
180 				for (q = s; *q != '/' && *q != '\0'; q++)
181 					continue;
182 				if (*q != '/')
183 					break;
184 				de = devfs_find(dd, s, q - s);
185 				if (de == NULL) {
186 					de = devfs_vmkdir(s, q - s, dd);
187 					de->de_inode = dm->dm_inode++;
188 					TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
189 					dd->de_links++;
190 				}
191 				s = q + 1;
192 				dd = de;
193 			}
194 			de = devfs_newdirent(s, q - s);
195 			if (dev->si_flags & SI_ALIAS) {
196 				de->de_inode = dm->dm_inode++;
197 				de->de_uid = 0;
198 				de->de_gid = 0;
199 				de->de_mode = 0666;
200 				de->de_dirent->d_type = DT_LNK;
201 				pdev = dev->si_drv1;
202 				j = strlen(pdev->si_name) + 1;
203 				MALLOC(de->de_symlink, char *, j, M_DEVFS, M_WAITOK);
204 				bcopy(pdev->si_name, de->de_symlink, j);
205 			} else {
206 				de->de_inode = i;
207 				de->de_uid = dev->si_uid;
208 				de->de_gid = dev->si_gid;
209 				de->de_mode = dev->si_mode;
210 				de->de_dirent->d_type = DT_CHR;
211 			}
212 			dm->dm_dirent[i] = de;
213 			de->de_dir = dd;
214 			TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
215 #if 0
216 			printf("Add ino%d %s\n", i, dev->si_name);
217 #endif
218 		}
219 	}
220 	return (0);
221 }
222 
223 dev_t devfs_inot[NDEVINO];
224 int devfs_nino = 3;
225 unsigned devfs_generation;
226 
227 static void
228 devfs_create(dev_t dev)
229 {
230 	if (dev->si_inode == 0 && devfs_nino < NDEVINO)
231 		dev->si_inode = devfs_nino++;
232 	if (dev->si_inode == 0) {
233 		printf("NDEVINO too small\n");
234 		return;
235 	}
236 	devfs_inot[dev->si_inode] = dev;
237 	devfs_generation++;
238 }
239 
240 static void
241 devfs_destroy(dev_t dev)
242 {
243 	devfs_inot[dev->si_inode] = NULL;
244 	devfs_generation++;
245 }
246 
247 devfs_create_t *devfs_create_hook = devfs_create;
248 devfs_destroy_t *devfs_destroy_hook = devfs_destroy;
249 int devfs_present = 1;
250