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