summaryrefslogtreecommitdiffstats
path: root/fs/autofs/inode.c
blob: 54c518c89e4cf86a8fec90124f21d7ca2e776169 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/* -*- linux-c -*- --------------------------------------------------------- *
 *
 * linux/fs/autofs/inode.c
 *
 *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
 *
 * This file is part of the Linux kernel and is made available under
 * the terms of the GNU General Public License, version 2, or at your
 * option, any later version, incorporated herein by reference.
 *
 * ------------------------------------------------------------------------- */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/parser.h>
#include <linux/bitops.h>
#include <linux/magic.h>
#include "autofs_i.h"
#include <linux/module.h>

void autofs_kill_sb(struct super_block *sb)
{
	struct autofs_sb_info *sbi = autofs_sbi(sb);
	unsigned int n;

	if ( !sbi->catatonic )
		autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */

	autofs_hash_nuke(sbi);
	for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
		if ( test_bit(n, sbi->symlink_bitmap) )
			kfree(sbi->symlink[n].data);
	}

	kfree(sb->s_fs_info);

	DPRINTK(("autofs: shutting down\n"));
	kill_anon_super(sb);
}

static void autofs_read_inode(struct inode *inode);

static struct super_operations autofs_sops = {
	.read_inode	= autofs_read_inode,
	.statfs		= simple_statfs,
};

enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};

static match_table_t autofs_tokens = {
	{Opt_fd, "fd=%u"},
	{Opt_uid, "uid=%u"},
	{Opt_gid, "gid=%u"},
	{Opt_pgrp, "pgrp=%u"},
	{Opt_minproto, "minproto=%u"},
	{Opt_maxproto, "maxproto=%u"},
	{Opt_err, NULL}
};

static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;

	*uid = current->uid;
	*gid = current->gid;
	*pgrp = process_group(current);

	*minproto = *maxproto = AUTOFS_PROTO_VERSION;

	*pipefd = -1;

	if (!options)
		return 1;

	while ((p = strsep(&options, ",")) != NULL) {
		int token;
		if (!*p)
			continue;

		token = match_token(p, autofs_tokens, args);
		switch (token) {
		case Opt_fd:
			if (match_int(&args[0], &option))
				return 1;
			*pipefd = option;
			break;
		case Opt_uid:
			if (match_int(&args[0], &option))
				return 1;
			*uid = option;
			break;
		case Opt_gid:
			if (match_int(&args[0], &option))
				return 1;
			*gid = option;
			break;
		case Opt_pgrp:
			if (match_int(&args[0], &option))
				return 1;
			*pgrp = option;
			break;
		case Opt_minproto:
			if (match_int(&args[0], &option))
				return 1;
			*minproto = option;
			break;
		case Opt_maxproto:
			if (match_int(&args[0], &option))
				return 1;
			*maxproto = option;
			break;
		default:
			return 1;
		}
	}
	return (*pipefd < 0);
}

int autofs_fill_super(struct super_block *s, void *data, int silent)
{
	struct inode * root_inode;
	struct dentry * root;
	struct file * pipe;
	int pipefd;
	struct autofs_sb_info *sbi;
	int minproto, maxproto;

	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
	if ( !sbi )
		goto fail_unlock;
	DPRINTK(("autofs: starting up, sbi = %p\n",sbi));

	s->s_fs_info = sbi;
	sbi->magic = AUTOFS_SBI_MAGIC;
	sbi->catatonic = 0;
	sbi->exp_timeout = 0;
	sbi->oz_pgrp = process_group(current);
	autofs_initialize_hash(&sbi->dirhash);
	sbi->queues = NULL;
	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
	sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
	s->s_blocksize = 1024;
	s->s_blocksize_bits = 10;
	s->s_magic = AUTOFS_SUPER_MAGIC;
	s->s_op = &autofs_sops;
	s->s_time_gran = 1;
	sbi->sb = s;

	root_inode = iget(s, AUTOFS_ROOT_INO);
	root = d_alloc_root(root_inode);
	pipe = NULL;

	if (!root)
		goto fail_iput;

	/* Can this call block?  - WTF cares? s is locked. */
	if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) {
		printk("autofs: called with bogus options\n");
		goto fail_dput;
	}

	/* Couldn't this be tested earlier? */
	if ( minproto > AUTOFS_PROTO_VERSION || 
	     maxproto < AUTOFS_PROTO_VERSION ) {
		printk("autofs: kernel does not match daemon version\n");
		goto fail_dput;
	}

	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
	pipe = fget(pipefd);
	
	if ( !pipe ) {
		printk("autofs: could not open pipe file descriptor\n");
		goto fail_dput;
	}
	if ( !pipe->f_op || !pipe->f_op->write )
		goto fail_fput;
	sbi->pipe = pipe;

	/*
	 * Success! Install the root dentry now to indicate completion.
	 */
	s->s_root = root;
	return 0;

fail_fput:
	printk("autofs: pipe file descriptor does not contain proper ops\n");
	fput(pipe);
fail_dput:
	dput(root);
	goto fail_free;
fail_iput:
	printk("autofs: get root dentry failed\n");
	iput(root_inode);
fail_free:
	kfree(sbi);
fail_unlock:
	return -EINVAL;
}

static void autofs_read_inode(struct inode *inode)
{
	ino_t ino = inode->i_ino;
	unsigned int n;
	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);

	/* Initialize to the default case (stub directory) */

	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
	inode->i_nlink = 2;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_blocks = 0;

	if ( ino == AUTOFS_ROOT_INO ) {
		inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
		inode->i_op = &autofs_root_inode_operations;
		inode->i_fop = &autofs_root_operations;
		inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
		return;
	} 
	
	inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
	inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
	
	if ( ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO ) {
		/* Symlink inode - should be in symlink list */
		struct autofs_symlink *sl;

		n = ino - AUTOFS_FIRST_SYMLINK;
		if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
			printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
			return;
		}
		
		inode->i_op = &autofs_symlink_inode_operations;
		sl = &sbi->symlink[n];
		inode->i_private = sl;
		inode->i_mode = S_IFLNK | S_IRWXUGO;
		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
		inode->i_size = sl->len;
		inode->i_nlink = 1;
	}
}
OpenPOWER on IntegriCloud