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 = 0;
40 ino->gid = 0;
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 vfsmount * mnt)73 static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
74 {
75 struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);
76 struct inode *root_inode = mnt->mnt_sb->s_root->d_inode;
77
78 if (!sbi)
79 return 0;
80
81 seq_printf(m, ",fd=%d", sbi->pipefd);
82 if (root_inode->i_uid != 0)
83 seq_printf(m, ",uid=%u", root_inode->i_uid);
84 if (root_inode->i_gid != 0)
85 seq_printf(m, ",gid=%u", root_inode->i_gid);
86 seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
87 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
88 seq_printf(m, ",minproto=%d", sbi->min_proto);
89 seq_printf(m, ",maxproto=%d", sbi->max_proto);
90
91 if (autofs_type_offset(sbi->type))
92 seq_printf(m, ",offset");
93 else if (autofs_type_direct(sbi->type))
94 seq_printf(m, ",direct");
95 else
96 seq_printf(m, ",indirect");
97
98 return 0;
99 }
100
autofs4_evict_inode(struct inode * inode)101 static void autofs4_evict_inode(struct inode *inode)
102 {
103 end_writeback(inode);
104 kfree(inode->i_private);
105 }
106
107 static const struct super_operations autofs4_sops = {
108 .statfs = simple_statfs,
109 .show_options = autofs4_show_options,
110 .evict_inode = autofs4_evict_inode,
111 };
112
113 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
114 Opt_indirect, Opt_direct, Opt_offset};
115
116 static const match_table_t tokens = {
117 {Opt_fd, "fd=%u"},
118 {Opt_uid, "uid=%u"},
119 {Opt_gid, "gid=%u"},
120 {Opt_pgrp, "pgrp=%u"},
121 {Opt_minproto, "minproto=%u"},
122 {Opt_maxproto, "maxproto=%u"},
123 {Opt_indirect, "indirect"},
124 {Opt_direct, "direct"},
125 {Opt_offset, "offset"},
126 {Opt_err, NULL}
127 };
128
parse_options(char * options,int * pipefd,uid_t * uid,gid_t * gid,pid_t * pgrp,unsigned int * type,int * minproto,int * maxproto)129 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
130 pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto)
131 {
132 char *p;
133 substring_t args[MAX_OPT_ARGS];
134 int option;
135
136 *uid = current_uid();
137 *gid = current_gid();
138 *pgrp = task_pgrp_nr(current);
139
140 *minproto = AUTOFS_MIN_PROTO_VERSION;
141 *maxproto = AUTOFS_MAX_PROTO_VERSION;
142
143 *pipefd = -1;
144
145 if (!options)
146 return 1;
147
148 while ((p = strsep(&options, ",")) != NULL) {
149 int token;
150 if (!*p)
151 continue;
152
153 token = match_token(p, tokens, args);
154 switch (token) {
155 case Opt_fd:
156 if (match_int(args, pipefd))
157 return 1;
158 break;
159 case Opt_uid:
160 if (match_int(args, &option))
161 return 1;
162 *uid = option;
163 break;
164 case Opt_gid:
165 if (match_int(args, &option))
166 return 1;
167 *gid = option;
168 break;
169 case Opt_pgrp:
170 if (match_int(args, &option))
171 return 1;
172 *pgrp = option;
173 break;
174 case Opt_minproto:
175 if (match_int(args, &option))
176 return 1;
177 *minproto = option;
178 break;
179 case Opt_maxproto:
180 if (match_int(args, &option))
181 return 1;
182 *maxproto = option;
183 break;
184 case Opt_indirect:
185 set_autofs_type_indirect(type);
186 break;
187 case Opt_direct:
188 set_autofs_type_direct(type);
189 break;
190 case Opt_offset:
191 set_autofs_type_offset(type);
192 break;
193 default:
194 return 1;
195 }
196 }
197 return (*pipefd < 0);
198 }
199
autofs4_fill_super(struct super_block * s,void * data,int silent)200 int autofs4_fill_super(struct super_block *s, void *data, int silent)
201 {
202 struct inode * root_inode;
203 struct dentry * root;
204 struct file * pipe;
205 int pipefd;
206 struct autofs_sb_info *sbi;
207 struct autofs_info *ino;
208
209 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
210 if (!sbi)
211 goto fail_unlock;
212 DPRINTK("starting up, sbi = %p",sbi);
213
214 s->s_fs_info = sbi;
215 sbi->magic = AUTOFS_SBI_MAGIC;
216 sbi->pipefd = -1;
217 sbi->pipe = NULL;
218 sbi->catatonic = 1;
219 sbi->exp_timeout = 0;
220 sbi->oz_pgrp = task_pgrp_nr(current);
221 sbi->sb = s;
222 sbi->version = 0;
223 sbi->sub_version = 0;
224 set_autofs_type_indirect(&sbi->type);
225 sbi->min_proto = 0;
226 sbi->max_proto = 0;
227 mutex_init(&sbi->wq_mutex);
228 spin_lock_init(&sbi->fs_lock);
229 sbi->queues = NULL;
230 spin_lock_init(&sbi->lookup_lock);
231 INIT_LIST_HEAD(&sbi->active_list);
232 INIT_LIST_HEAD(&sbi->expiring_list);
233 s->s_blocksize = 1024;
234 s->s_blocksize_bits = 10;
235 s->s_magic = AUTOFS_SUPER_MAGIC;
236 s->s_op = &autofs4_sops;
237 s->s_d_op = &autofs4_dentry_operations;
238 s->s_time_gran = 1;
239
240 /*
241 * Get the root inode and dentry, but defer checking for errors.
242 */
243 ino = autofs4_new_ino(sbi);
244 if (!ino)
245 goto fail_free;
246 root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
247 if (!root_inode)
248 goto fail_ino;
249
250 root = d_alloc_root(root_inode);
251 if (!root)
252 goto fail_iput;
253 pipe = NULL;
254
255 root->d_fsdata = ino;
256
257 /* Can this call block? */
258 if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
259 &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
260 &sbi->max_proto)) {
261 printk("autofs: called with bogus options\n");
262 goto fail_dput;
263 }
264
265 if (autofs_type_trigger(sbi->type))
266 __managed_dentry_set_managed(root);
267
268 root_inode->i_fop = &autofs4_root_operations;
269 root_inode->i_op = &autofs4_dir_inode_operations;
270
271 /* Couldn't this be tested earlier? */
272 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
273 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
274 printk("autofs: kernel does not match daemon version "
275 "daemon (%d, %d) kernel (%d, %d)\n",
276 sbi->min_proto, sbi->max_proto,
277 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
278 goto fail_dput;
279 }
280
281 /* Establish highest kernel protocol version */
282 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
283 sbi->version = AUTOFS_MAX_PROTO_VERSION;
284 else
285 sbi->version = sbi->max_proto;
286 sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
287
288 DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
289 pipe = fget(pipefd);
290
291 if (!pipe) {
292 printk("autofs: could not open pipe file descriptor\n");
293 goto fail_dput;
294 }
295 if (!pipe->f_op || !pipe->f_op->write)
296 goto fail_fput;
297 sbi->pipe = pipe;
298 sbi->pipefd = pipefd;
299 sbi->catatonic = 0;
300
301 /*
302 * Success! Install the root dentry now to indicate completion.
303 */
304 s->s_root = root;
305 return 0;
306
307 /*
308 * Failure ... clean up.
309 */
310 fail_fput:
311 printk("autofs: pipe file descriptor does not contain proper ops\n");
312 fput(pipe);
313 /* fall through */
314 fail_dput:
315 dput(root);
316 goto fail_free;
317 fail_iput:
318 printk("autofs: get root dentry failed\n");
319 iput(root_inode);
320 fail_ino:
321 kfree(ino);
322 fail_free:
323 kfree(sbi);
324 s->s_fs_info = NULL;
325 fail_unlock:
326 return -EINVAL;
327 }
328
autofs4_get_inode(struct super_block * sb,mode_t mode)329 struct inode *autofs4_get_inode(struct super_block *sb, mode_t mode)
330 {
331 struct inode *inode = new_inode(sb);
332
333 if (inode == NULL)
334 return NULL;
335
336 inode->i_mode = mode;
337 if (sb->s_root) {
338 inode->i_uid = sb->s_root->d_inode->i_uid;
339 inode->i_gid = sb->s_root->d_inode->i_gid;
340 }
341 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
342 inode->i_ino = get_next_ino();
343
344 if (S_ISDIR(mode)) {
345 inode->i_nlink = 2;
346 inode->i_op = &autofs4_dir_inode_operations;
347 inode->i_fop = &autofs4_dir_operations;
348 } else if (S_ISLNK(mode)) {
349 inode->i_op = &autofs4_symlink_inode_operations;
350 }
351
352 return inode;
353 }
354