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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/devpts/inode.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/devpts/inode.c')
-rw-r--r--fs/devpts/inode.c242
1 files changed, 242 insertions, 0 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
new file mode 100644
index 000000000000..1571c8d6c232
--- /dev/null
+++ b/fs/devpts/inode.c
@@ -0,0 +1,242 @@
1/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/devpts/inode.c
4 *
5 * Copyright 1998-2004 H. Peter Anvin -- All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ------------------------------------------------------------------------- */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/fs.h>
16#include <linux/sched.h>
17#include <linux/namei.h>
18#include <linux/mount.h>
19#include <linux/tty.h>
20#include <linux/devpts_fs.h>
21#include <linux/xattr.h>
22
23#define DEVPTS_SUPER_MAGIC 0x1cd1
24
25extern struct xattr_handler devpts_xattr_security_handler;
26
27static struct xattr_handler *devpts_xattr_handlers[] = {
28#ifdef CONFIG_DEVPTS_FS_SECURITY
29 &devpts_xattr_security_handler,
30#endif
31 NULL
32};
33
34static struct inode_operations devpts_file_inode_operations = {
35#ifdef CONFIG_DEVPTS_FS_XATTR
36 .setxattr = generic_setxattr,
37 .getxattr = generic_getxattr,
38 .listxattr = generic_listxattr,
39 .removexattr = generic_removexattr,
40#endif
41};
42
43static struct vfsmount *devpts_mnt;
44static struct dentry *devpts_root;
45
46static struct {
47 int setuid;
48 int setgid;
49 uid_t uid;
50 gid_t gid;
51 umode_t mode;
52} config = {.mode = 0600};
53
54static int devpts_remount(struct super_block *sb, int *flags, char *data)
55{
56 int setuid = 0;
57 int setgid = 0;
58 uid_t uid = 0;
59 gid_t gid = 0;
60 umode_t mode = 0600;
61 char *this_char;
62
63 this_char = NULL;
64 while ((this_char = strsep(&data, ",")) != NULL) {
65 int n;
66 char dummy;
67 if (!*this_char)
68 continue;
69 if (sscanf(this_char, "uid=%i%c", &n, &dummy) == 1) {
70 setuid = 1;
71 uid = n;
72 } else if (sscanf(this_char, "gid=%i%c", &n, &dummy) == 1) {
73 setgid = 1;
74 gid = n;
75 } else if (sscanf(this_char, "mode=%o%c", &n, &dummy) == 1)
76 mode = n & ~S_IFMT;
77 else {
78 printk("devpts: called with bogus options\n");
79 return -EINVAL;
80 }
81 }
82 config.setuid = setuid;
83 config.setgid = setgid;
84 config.uid = uid;
85 config.gid = gid;
86 config.mode = mode;
87
88 return 0;
89}
90
91static struct super_operations devpts_sops = {
92 .statfs = simple_statfs,
93 .remount_fs = devpts_remount,
94};
95
96static int
97devpts_fill_super(struct super_block *s, void *data, int silent)
98{
99 struct inode * inode;
100
101 s->s_blocksize = 1024;
102 s->s_blocksize_bits = 10;
103 s->s_magic = DEVPTS_SUPER_MAGIC;
104 s->s_op = &devpts_sops;
105 s->s_xattr = devpts_xattr_handlers;
106 s->s_time_gran = 1;
107
108 inode = new_inode(s);
109 if (!inode)
110 goto fail;
111 inode->i_ino = 1;
112 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
113 inode->i_blocks = 0;
114 inode->i_blksize = 1024;
115 inode->i_uid = inode->i_gid = 0;
116 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
117 inode->i_op = &simple_dir_inode_operations;
118 inode->i_fop = &simple_dir_operations;
119 inode->i_nlink = 2;
120
121 devpts_root = s->s_root = d_alloc_root(inode);
122 if (s->s_root)
123 return 0;
124
125 printk("devpts: get root dentry failed\n");
126 iput(inode);
127fail:
128 return -ENOMEM;
129}
130
131static struct super_block *devpts_get_sb(struct file_system_type *fs_type,
132 int flags, const char *dev_name, void *data)
133{
134 return get_sb_single(fs_type, flags, data, devpts_fill_super);
135}
136
137static struct file_system_type devpts_fs_type = {
138 .owner = THIS_MODULE,
139 .name = "devpts",
140 .get_sb = devpts_get_sb,
141 .kill_sb = kill_anon_super,
142};
143
144/*
145 * The normal naming convention is simply /dev/pts/<number>; this conforms
146 * to the System V naming convention
147 */
148
149static struct dentry *get_node(int num)
150{
151 char s[12];
152 struct dentry *root = devpts_root;
153 down(&root->d_inode->i_sem);
154 return lookup_one_len(s, root, sprintf(s, "%d", num));
155}
156
157int devpts_pty_new(struct tty_struct *tty)
158{
159 int number = tty->index;
160 struct tty_driver *driver = tty->driver;
161 dev_t device = MKDEV(driver->major, driver->minor_start+number);
162 struct dentry *dentry;
163 struct inode *inode = new_inode(devpts_mnt->mnt_sb);
164
165 /* We're supposed to be given the slave end of a pty */
166 BUG_ON(driver->type != TTY_DRIVER_TYPE_PTY);
167 BUG_ON(driver->subtype != PTY_TYPE_SLAVE);
168
169 if (!inode)
170 return -ENOMEM;
171
172 inode->i_ino = number+2;
173 inode->i_blksize = 1024;
174 inode->i_uid = config.setuid ? config.uid : current->fsuid;
175 inode->i_gid = config.setgid ? config.gid : current->fsgid;
176 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
177 init_special_inode(inode, S_IFCHR|config.mode, device);
178 inode->i_op = &devpts_file_inode_operations;
179 inode->u.generic_ip = tty;
180
181 dentry = get_node(number);
182 if (!IS_ERR(dentry) && !dentry->d_inode)
183 d_instantiate(dentry, inode);
184
185 up(&devpts_root->d_inode->i_sem);
186
187 return 0;
188}
189
190struct tty_struct *devpts_get_tty(int number)
191{
192 struct dentry *dentry = get_node(number);
193 struct tty_struct *tty;
194
195 tty = NULL;
196 if (!IS_ERR(dentry)) {
197 if (dentry->d_inode)
198 tty = dentry->d_inode->u.generic_ip;
199 dput(dentry);
200 }
201
202 up(&devpts_root->d_inode->i_sem);
203
204 return tty;
205}
206
207void devpts_pty_kill(int number)
208{
209 struct dentry *dentry = get_node(number);
210
211 if (!IS_ERR(dentry)) {
212 struct inode *inode = dentry->d_inode;
213 if (inode) {
214 inode->i_nlink--;
215 d_delete(dentry);
216 dput(dentry);
217 }
218 dput(dentry);
219 }
220 up(&devpts_root->d_inode->i_sem);
221}
222
223static int __init init_devpts_fs(void)
224{
225 int err = register_filesystem(&devpts_fs_type);
226 if (!err) {
227 devpts_mnt = kern_mount(&devpts_fs_type);
228 if (IS_ERR(devpts_mnt))
229 err = PTR_ERR(devpts_mnt);
230 }
231 return err;
232}
233
234static void __exit exit_devpts_fs(void)
235{
236 unregister_filesystem(&devpts_fs_type);
237 mntput(devpts_mnt);
238}
239
240module_init(init_devpts_fs)
241module_exit(exit_devpts_fs)
242MODULE_LICENSE("GPL");