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 /* Free wait queues, close pipe */
61 autofs4_catatonic_mode(sbi);
62 put_pid(sbi->oz_pgrp);
63 }
64
65 DPRINTK("shutting down");
66 kill_litter_super(sb);
67 if (sbi)
68 kfree_rcu(sbi, rcu);
69 }
70
autofs4_show_options(struct seq_file * m,struct dentry * root)71 static int autofs4_show_options(struct seq_file *m, struct dentry *root)
72 {
73 struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
74 struct inode *root_inode = d_inode(root->d_sb->s_root);
75
76 if (!sbi)
77 return 0;
78
79 seq_printf(m, ",fd=%d", sbi->pipefd);
80 if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
81 seq_printf(m, ",uid=%u",
82 from_kuid_munged(&init_user_ns, root_inode->i_uid));
83 if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
84 seq_printf(m, ",gid=%u",
85 from_kgid_munged(&init_user_ns, root_inode->i_gid));
86 seq_printf(m, ",pgrp=%d", pid_vnr(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 clear_inode(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,kuid_t * uid,kgid_t * gid,int * pgrp,bool * pgrp_set,unsigned int * type,int * minproto,int * maxproto)129 static int parse_options(char *options, int *pipefd, kuid_t *uid, kgid_t *gid,
130 int *pgrp, bool *pgrp_set, unsigned int *type,
131 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
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 = make_kuid(current_user_ns(), option);
163 if (!uid_valid(*uid))
164 return 1;
165 break;
166 case Opt_gid:
167 if (match_int(args, &option))
168 return 1;
169 *gid = make_kgid(current_user_ns(), option);
170 if (!gid_valid(*gid))
171 return 1;
172 break;
173 case Opt_pgrp:
174 if (match_int(args, &option))
175 return 1;
176 *pgrp = option;
177 *pgrp_set = true;
178 break;
179 case Opt_minproto:
180 if (match_int(args, &option))
181 return 1;
182 *minproto = option;
183 break;
184 case Opt_maxproto:
185 if (match_int(args, &option))
186 return 1;
187 *maxproto = option;
188 break;
189 case Opt_indirect:
190 set_autofs_type_indirect(type);
191 break;
192 case Opt_direct:
193 set_autofs_type_direct(type);
194 break;
195 case Opt_offset:
196 set_autofs_type_offset(type);
197 break;
198 default:
199 return 1;
200 }
201 }
202 return (*pipefd < 0);
203 }
204
autofs4_fill_super(struct super_block * s,void * data,int silent)205 int autofs4_fill_super(struct super_block *s, void *data, int silent)
206 {
207 struct inode * root_inode;
208 struct dentry * root;
209 struct file * pipe;
210 int pipefd;
211 struct autofs_sb_info *sbi;
212 struct autofs_info *ino;
213 int pgrp = 0;
214 bool pgrp_set = false;
215 int ret = -EINVAL;
216
217 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
218 if (!sbi)
219 return -ENOMEM;
220 DPRINTK("starting up, sbi = %p",sbi);
221
222 s->s_fs_info = sbi;
223 sbi->magic = AUTOFS_SBI_MAGIC;
224 sbi->pipefd = -1;
225 sbi->pipe = NULL;
226 sbi->catatonic = 1;
227 sbi->exp_timeout = 0;
228 sbi->oz_pgrp = NULL;
229 sbi->sb = s;
230 sbi->version = 0;
231 sbi->sub_version = 0;
232 set_autofs_type_indirect(&sbi->type);
233 sbi->min_proto = 0;
234 sbi->max_proto = 0;
235 mutex_init(&sbi->wq_mutex);
236 mutex_init(&sbi->pipe_mutex);
237 spin_lock_init(&sbi->fs_lock);
238 sbi->queues = NULL;
239 spin_lock_init(&sbi->lookup_lock);
240 INIT_LIST_HEAD(&sbi->active_list);
241 INIT_LIST_HEAD(&sbi->expiring_list);
242 s->s_blocksize = 1024;
243 s->s_blocksize_bits = 10;
244 s->s_magic = AUTOFS_SUPER_MAGIC;
245 s->s_op = &autofs4_sops;
246 s->s_d_op = &autofs4_dentry_operations;
247 s->s_time_gran = 1;
248
249 /*
250 * Get the root inode and dentry, but defer checking for errors.
251 */
252 ino = autofs4_new_ino(sbi);
253 if (!ino) {
254 ret = -ENOMEM;
255 goto fail_free;
256 }
257 root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
258 root = d_make_root(root_inode);
259 if (!root)
260 goto fail_ino;
261 pipe = NULL;
262
263 root->d_fsdata = ino;
264
265 /* Can this call block? */
266 if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
267 &pgrp, &pgrp_set, &sbi->type, &sbi->min_proto,
268 &sbi->max_proto)) {
269 printk("autofs: called with bogus options\n");
270 goto fail_dput;
271 }
272
273 if (pgrp_set) {
274 sbi->oz_pgrp = find_get_pid(pgrp);
275 if (!sbi->oz_pgrp) {
276 pr_warn("autofs: could not find process group %d\n",
277 pgrp);
278 goto fail_dput;
279 }
280 } else {
281 sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
282 }
283
284 if (autofs_type_trigger(sbi->type))
285 __managed_dentry_set_managed(root);
286
287 root_inode->i_fop = &autofs4_root_operations;
288 root_inode->i_op = &autofs4_dir_inode_operations;
289
290 /* Couldn't this be tested earlier? */
291 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
292 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
293 printk("autofs: kernel does not match daemon version "
294 "daemon (%d, %d) kernel (%d, %d)\n",
295 sbi->min_proto, sbi->max_proto,
296 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
297 goto fail_dput;
298 }
299
300 /* Establish highest kernel protocol version */
301 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
302 sbi->version = AUTOFS_MAX_PROTO_VERSION;
303 else
304 sbi->version = sbi->max_proto;
305 sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
306
307 DPRINTK("pipe fd = %d, pgrp = %u", pipefd, pid_nr(sbi->oz_pgrp));
308 pipe = fget(pipefd);
309
310 if (!pipe) {
311 printk("autofs: could not open pipe file descriptor\n");
312 goto fail_dput;
313 }
314 ret = autofs_prepare_pipe(pipe);
315 if (ret < 0)
316 goto fail_fput;
317 sbi->pipe = pipe;
318 sbi->pipefd = pipefd;
319 sbi->catatonic = 0;
320
321 /*
322 * Success! Install the root dentry now to indicate completion.
323 */
324 s->s_root = root;
325 return 0;
326
327 /*
328 * Failure ... clean up.
329 */
330 fail_fput:
331 printk("autofs: pipe file descriptor does not contain proper ops\n");
332 fput(pipe);
333 /* fall through */
334 fail_dput:
335 dput(root);
336 goto fail_free;
337 fail_ino:
338 kfree(ino);
339 fail_free:
340 put_pid(sbi->oz_pgrp);
341 kfree(sbi);
342 s->s_fs_info = NULL;
343 return ret;
344 }
345
autofs4_get_inode(struct super_block * sb,umode_t mode)346 struct inode *autofs4_get_inode(struct super_block *sb, umode_t mode)
347 {
348 struct inode *inode = new_inode(sb);
349
350 if (inode == NULL)
351 return NULL;
352
353 inode->i_mode = mode;
354 if (sb->s_root) {
355 inode->i_uid = d_inode(sb->s_root)->i_uid;
356 inode->i_gid = d_inode(sb->s_root)->i_gid;
357 }
358 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
359 inode->i_ino = get_next_ino();
360
361 if (S_ISDIR(mode)) {
362 set_nlink(inode, 2);
363 inode->i_op = &autofs4_dir_inode_operations;
364 inode->i_fop = &autofs4_dir_operations;
365 } else if (S_ISLNK(mode)) {
366 inode->i_op = &autofs4_symlink_inode_operations;
367 }
368
369 return inode;
370 }
371