blob: 4888c1fabbf714b32fad246d03ee7bb8db231e6a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/autofs/inode.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- 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/kernel.h>
14#include <linux/mm.h>
15#include <linux/slab.h>
16#include <linux/file.h>
17#include <linux/parser.h>
18#include <linux/bitops.h>
19#include "autofs_i.h"
20#include <linux/module.h>
21
22static void autofs_put_super(struct super_block *sb)
23{
24 struct autofs_sb_info *sbi = autofs_sbi(sb);
25 unsigned int n;
26
27 if ( !sbi->catatonic )
28 autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
29
30 autofs_hash_nuke(&sbi->dirhash);
31 for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
32 if ( test_bit(n, sbi->symlink_bitmap) )
33 kfree(sbi->symlink[n].data);
34 }
35
36 kfree(sb->s_fs_info);
37
38 DPRINTK(("autofs: shutting down\n"));
39}
40
41static void autofs_read_inode(struct inode *inode);
42
43static struct super_operations autofs_sops = {
44 .read_inode = autofs_read_inode,
45 .put_super = autofs_put_super,
46 .statfs = simple_statfs,
47};
48
49enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
50
51static match_table_t autofs_tokens = {
52 {Opt_fd, "fd=%u"},
53 {Opt_uid, "uid=%u"},
54 {Opt_gid, "gid=%u"},
55 {Opt_pgrp, "pgrp=%u"},
56 {Opt_minproto, "minproto=%u"},
57 {Opt_maxproto, "maxproto=%u"},
58 {Opt_err, NULL}
59};
60
61static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto)
62{
63 char *p;
64 substring_t args[MAX_OPT_ARGS];
65 int option;
66
67 *uid = current->uid;
68 *gid = current->gid;
69 *pgrp = process_group(current);
70
71 *minproto = *maxproto = AUTOFS_PROTO_VERSION;
72
73 *pipefd = -1;
74
75 if (!options)
76 return 1;
77
78 while ((p = strsep(&options, ",")) != NULL) {
79 int token;
80 if (!*p)
81 continue;
82
83 token = match_token(p, autofs_tokens, args);
84 switch (token) {
85 case Opt_fd:
86 if (match_int(&args[0], &option))
87 return 1;
88 *pipefd = option;
89 break;
90 case Opt_uid:
91 if (match_int(&args[0], &option))
92 return 1;
93 *uid = option;
94 break;
95 case Opt_gid:
96 if (match_int(&args[0], &option))
97 return 1;
98 *gid = option;
99 break;
100 case Opt_pgrp:
101 if (match_int(&args[0], &option))
102 return 1;
103 *pgrp = option;
104 break;
105 case Opt_minproto:
106 if (match_int(&args[0], &option))
107 return 1;
108 *minproto = option;
109 break;
110 case Opt_maxproto:
111 if (match_int(&args[0], &option))
112 return 1;
113 *maxproto = option;
114 break;
115 default:
116 return 1;
117 }
118 }
119 return (*pipefd < 0);
120}
121
122int autofs_fill_super(struct super_block *s, void *data, int silent)
123{
124 struct inode * root_inode;
125 struct dentry * root;
126 struct file * pipe;
127 int pipefd;
128 struct autofs_sb_info *sbi;
129 int minproto, maxproto;
130
131 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
132 if ( !sbi )
133 goto fail_unlock;
134 memset(sbi, 0, sizeof(*sbi));
135 DPRINTK(("autofs: starting up, sbi = %p\n",sbi));
136
137 s->s_fs_info = sbi;
138 sbi->magic = AUTOFS_SBI_MAGIC;
139 sbi->catatonic = 0;
140 sbi->exp_timeout = 0;
141 sbi->oz_pgrp = process_group(current);
142 autofs_initialize_hash(&sbi->dirhash);
143 sbi->queues = NULL;
144 memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
145 sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
146 s->s_blocksize = 1024;
147 s->s_blocksize_bits = 10;
148 s->s_magic = AUTOFS_SUPER_MAGIC;
149 s->s_op = &autofs_sops;
150 s->s_time_gran = 1;
151
152 root_inode = iget(s, AUTOFS_ROOT_INO);
153 root = d_alloc_root(root_inode);
154 pipe = NULL;
155
156 if (!root)
157 goto fail_iput;
158
159 /* Can this call block? - WTF cares? s is locked. */
160 if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) {
161 printk("autofs: called with bogus options\n");
162 goto fail_dput;
163 }
164
165 /* Couldn't this be tested earlier? */
166 if ( minproto > AUTOFS_PROTO_VERSION ||
167 maxproto < AUTOFS_PROTO_VERSION ) {
168 printk("autofs: kernel does not match daemon version\n");
169 goto fail_dput;
170 }
171
172 DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
173 pipe = fget(pipefd);
174
175 if ( !pipe ) {
176 printk("autofs: could not open pipe file descriptor\n");
177 goto fail_dput;
178 }
179 if ( !pipe->f_op || !pipe->f_op->write )
180 goto fail_fput;
181 sbi->pipe = pipe;
182
183 /*
184 * Success! Install the root dentry now to indicate completion.
185 */
186 s->s_root = root;
187 return 0;
188
189fail_fput:
190 printk("autofs: pipe file descriptor does not contain proper ops\n");
191 fput(pipe);
192fail_dput:
193 dput(root);
194 goto fail_free;
195fail_iput:
196 printk("autofs: get root dentry failed\n");
197 iput(root_inode);
198fail_free:
199 kfree(sbi);
200fail_unlock:
201 return -EINVAL;
202}
203
204static void autofs_read_inode(struct inode *inode)
205{
206 ino_t ino = inode->i_ino;
207 unsigned int n;
208 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
209
210 /* Initialize to the default case (stub directory) */
211
212 inode->i_op = &simple_dir_inode_operations;
213 inode->i_fop = &simple_dir_operations;
214 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
215 inode->i_nlink = 2;
216 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
217 inode->i_blocks = 0;
218 inode->i_blksize = 1024;
219
220 if ( ino == AUTOFS_ROOT_INO ) {
221 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
222 inode->i_op = &autofs_root_inode_operations;
223 inode->i_fop = &autofs_root_operations;
224 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
225 return;
226 }
227
228 inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
229 inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
230
231 if ( ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO ) {
232 /* Symlink inode - should be in symlink list */
233 struct autofs_symlink *sl;
234
235 n = ino - AUTOFS_FIRST_SYMLINK;
236 if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
237 printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
238 return;
239 }
240
241 inode->i_op = &autofs_symlink_inode_operations;
242 sl = &sbi->symlink[n];
243 inode->u.generic_ip = sl;
244 inode->i_mode = S_IFLNK | S_IRWXUGO;
245 inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
246 inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
247 inode->i_size = sl->len;
248 inode->i_nlink = 1;
249 }
250}