1 /* -*- c -*- --------------------------------------------------------------- *
2 *
3 * linux/fs/autofs/inode.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
7 *
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
11 *
12 * ------------------------------------------------------------------------- */
13
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/file.h>
17 #include <linux/seq_file.h>
18 #include <linux/pagemap.h>
19 #include <linux/parser.h>
20 #include <linux/bitops.h>
21 #include <linux/magic.h>
22 #include <linux/compat.h>
23 #include "autofs_i.h"
24 #include <linux/module.h>
25
autofs4_new_ino(struct autofs_sb_info * sbi)26 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *sbi)
27 {
28 struct autofs_info *ino = kzalloc(sizeof(*ino), GFP_KERNEL);
29 if (ino) {
30 INIT_LIST_HEAD(&ino->active);
31 INIT_LIST_HEAD(&ino->expiring);
32 ino->last_used = jiffies;
33 ino->sbi = sbi;
34 }
35 return ino;
36 }
37
autofs4_clean_ino(struct autofs_info * ino)38 void autofs4_clean_ino(struct autofs_info *ino)
39 {
40 ino->uid = 0;
41 ino->gid = 0;
42 ino->last_used = jiffies;
43 }
44
autofs4_free_ino(struct autofs_info * ino)45 void autofs4_free_ino(struct autofs_info *ino)
46 {
47 kfree(ino);
48 }
49
autofs4_kill_sb(struct super_block * sb)50 void autofs4_kill_sb(struct super_block *sb)
51 {
52 struct autofs_sb_info *sbi = autofs4_sbi(sb);
53
54 /*
55 * In the event of a failure in get_sb_nodev the superblock
56 * info is not present so nothing else has been setup, so
57 * just call kill_anon_super when we are called from
58 * deactivate_super.
59 */
60 if (!sbi)
61 goto out_kill_sb;
62
63 /* Free wait queues, close pipe */
64 autofs4_catatonic_mode(sbi);
65
66 sb->s_fs_info = NULL;
67 kfree(sbi);
68
69 out_kill_sb:
70 DPRINTK("shutting down");
71 kill_litter_super(sb);
72 }
73
autofs4_show_options(struct seq_file * m,struct dentry * root)74 static int autofs4_show_options(struct seq_file *m, struct dentry *root)
75 {
76 struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
77 struct inode *root_inode = root->d_sb->s_root->d_inode;
78
79 if (!sbi)
80 return 0;
81
82 seq_printf(m, ",fd=%d", sbi->pipefd);
83 if (root_inode->i_uid != 0)
84 seq_printf(m, ",uid=%u", root_inode->i_uid);
85 if (root_inode->i_gid != 0)
86 seq_printf(m, ",gid=%u", root_inode->i_gid);
87 seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
88 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
89 seq_printf(m, ",minproto=%d", sbi->min_proto);
90 seq_printf(m, ",maxproto=%d", sbi->max_proto);
91
92 if (autofs_type_offset(sbi->type))
93 seq_printf(m, ",offset");
94 else if (autofs_type_direct(sbi->type))
95 seq_printf(m, ",direct");
96 else
97 seq_printf(m, ",indirect");
98
99 return 0;
100 }
101
autofs4_evict_inode(struct inode * inode)102 static void autofs4_evict_inode(struct inode *inode)
103 {
104 end_writeback(inode);
105 kfree(inode->i_private);
106 }
107
108 static const struct super_operations autofs4_sops = {
109 .statfs = simple_statfs,
110 .show_options = autofs4_show_options,
111 .evict_inode = autofs4_evict_inode,
112 };
113
114 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
115 Opt_indirect, Opt_direct, Opt_offset};
116
117 static const match_table_t tokens = {
118 {Opt_fd, "fd=%u"},
119 {Opt_uid, "uid=%u"},
120 {Opt_gid, "gid=%u"},
121 {Opt_pgrp, "pgrp=%u"},
122 {Opt_minproto, "minproto=%u"},
123 {Opt_maxproto, "maxproto=%u"},
124 {Opt_indirect, "indirect"},
125 {Opt_direct, "direct"},
126 {Opt_offset, "offset"},
127 {Opt_err, NULL}
128 };
129
parse_options(char * options,int * pipefd,uid_t * uid,gid_t * gid,pid_t * pgrp,unsigned int * type,int * minproto,int * maxproto)130 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
131 pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto)
132 {
133 char *p;
134 substring_t args[MAX_OPT_ARGS];
135 int option;
136
137 *uid = current_uid();
138 *gid = current_gid();
139 *pgrp = task_pgrp_nr(current);
140
141 *minproto = AUTOFS_MIN_PROTO_VERSION;
142 *maxproto = AUTOFS_MAX_PROTO_VERSION;
143
144 *pipefd = -1;
145
146 if (!options)
147 return 1;
148
149 while ((p = strsep(&options, ",")) != NULL) {
150 int token;
151 if (!*p)
152 continue;
153
154 token = match_token(p, tokens, args);
155 switch (token) {
156 case Opt_fd:
157 if (match_int(args, pipefd))
158 return 1;
159 break;
160 case Opt_uid:
161 if (match_int(args, &option))
162 return 1;
163 *uid = option;
164 break;
165 case Opt_gid:
166 if (match_int(args, &option))
167 return 1;
168 *gid = option;
169 break;
170 case Opt_pgrp:
171 if (match_int(args, &option))
172 return 1;
173 *pgrp = option;
174 break;
175 case Opt_minproto:
176 if (match_int(args, &option))
177 return 1;
178 *minproto = option;
179 break;
180 case Opt_maxproto:
181 if (match_int(args, &option))
182 return 1;
183 *maxproto = option;
184 break;
185 case Opt_indirect:
186 set_autofs_type_indirect(type);
187 break;
188 case Opt_direct:
189 set_autofs_type_direct(type);
190 break;
191 case Opt_offset:
192 set_autofs_type_offset(type);
193 break;
194 default:
195 return 1;
196 }
197 }
198 return (*pipefd < 0);
199 }
200
autofs4_fill_super(struct super_block * s,void * data,int silent)201 int autofs4_fill_super(struct super_block *s, void *data, int silent)
202 {
203 struct inode * root_inode;
204 struct dentry * root;
205 struct file * pipe;
206 int pipefd;
207 struct autofs_sb_info *sbi;
208 struct autofs_info *ino;
209
210 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
211 if (!sbi)
212 goto fail_unlock;
213 DPRINTK("starting up, sbi = %p",sbi);
214
215 s->s_fs_info = sbi;
216 sbi->magic = AUTOFS_SBI_MAGIC;
217 sbi->pipefd = -1;
218 sbi->pipe = NULL;
219 sbi->catatonic = 1;
220 sbi->exp_timeout = 0;
221 sbi->oz_pgrp = task_pgrp_nr(current);
222 sbi->sb = s;
223 sbi->version = 0;
224 sbi->sub_version = 0;
225 set_autofs_type_indirect(&sbi->type);
226 sbi->min_proto = 0;
227 sbi->max_proto = 0;
228 sbi->compat_daemon = is_compat_task();
229 mutex_init(&sbi->wq_mutex);
230 mutex_init(&sbi->pipe_mutex);
231 spin_lock_init(&sbi->fs_lock);
232 sbi->queues = NULL;
233 spin_lock_init(&sbi->lookup_lock);
234 INIT_LIST_HEAD(&sbi->active_list);
235 INIT_LIST_HEAD(&sbi->expiring_list);
236 s->s_blocksize = 1024;
237 s->s_blocksize_bits = 10;
238 s->s_magic = AUTOFS_SUPER_MAGIC;
239 s->s_op = &autofs4_sops;
240 s->s_d_op = &autofs4_dentry_operations;
241 s->s_time_gran = 1;
242
243 /*
244 * Get the root inode and dentry, but defer checking for errors.
245 */
246 ino = autofs4_new_ino(sbi);
247 if (!ino)
248 goto fail_free;
249 root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
250 if (!root_inode)
251 goto fail_ino;
252
253 root = d_alloc_root(root_inode);
254 if (!root)
255 goto fail_iput;
256 pipe = NULL;
257
258 root->d_fsdata = ino;
259
260 /* Can this call block? */
261 if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
262 &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
263 &sbi->max_proto)) {
264 printk("autofs: called with bogus options\n");
265 goto fail_dput;
266 }
267
268 if (autofs_type_trigger(sbi->type))
269 __managed_dentry_set_managed(root);
270
271 root_inode->i_fop = &autofs4_root_operations;
272 root_inode->i_op = &autofs4_dir_inode_operations;
273
274 /* Couldn't this be tested earlier? */
275 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
276 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
277 printk("autofs: kernel does not match daemon version "
278 "daemon (%d, %d) kernel (%d, %d)\n",
279 sbi->min_proto, sbi->max_proto,
280 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
281 goto fail_dput;
282 }
283
284 /* Establish highest kernel protocol version */
285 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
286 sbi->version = AUTOFS_MAX_PROTO_VERSION;
287 else
288 sbi->version = sbi->max_proto;
289 sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
290
291 DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
292 pipe = fget(pipefd);
293
294 if (!pipe) {
295 printk("autofs: could not open pipe file descriptor\n");
296 goto fail_dput;
297 }
298 if (!pipe->f_op || !pipe->f_op->write)
299 goto fail_fput;
300 sbi->pipe = pipe;
301 sbi->pipefd = pipefd;
302 sbi->catatonic = 0;
303
304 /*
305 * Success! Install the root dentry now to indicate completion.
306 */
307 s->s_root = root;
308 return 0;
309
310 /*
311 * Failure ... clean up.
312 */
313 fail_fput:
314 printk("autofs: pipe file descriptor does not contain proper ops\n");
315 fput(pipe);
316 /* fall through */
317 fail_dput:
318 dput(root);
319 goto fail_free;
320 fail_iput:
321 printk("autofs: get root dentry failed\n");
322 iput(root_inode);
323 fail_ino:
324 kfree(ino);
325 fail_free:
326 kfree(sbi);
327 s->s_fs_info = NULL;
328 fail_unlock:
329 return -EINVAL;
330 }
331
autofs4_get_inode(struct super_block * sb,umode_t mode)332 struct inode *autofs4_get_inode(struct super_block *sb, umode_t mode)
333 {
334 struct inode *inode = new_inode(sb);
335
336 if (inode == NULL)
337 return NULL;
338
339 inode->i_mode = mode;
340 if (sb->s_root) {
341 inode->i_uid = sb->s_root->d_inode->i_uid;
342 inode->i_gid = sb->s_root->d_inode->i_gid;
343 }
344 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
345 inode->i_ino = get_next_ino();
346
347 if (S_ISDIR(mode)) {
348 set_nlink(inode, 2);
349 inode->i_op = &autofs4_dir_inode_operations;
350 inode->i_fop = &autofs4_dir_operations;
351 } else if (S_ISLNK(mode)) {
352 inode->i_op = &autofs4_symlink_inode_operations;
353 }
354
355 return inode;
356 }
357