1 /*
2 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
3 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
4 *
5 * This file is part of the Linux kernel and is made available under
6 * the terms of the GNU General Public License, version 2, or at your
7 * option, any later version, incorporated herein by reference.
8 */
9
10 #include <linux/seq_file.h>
11 #include <linux/pagemap.h>
12 #include <linux/parser.h>
13
14 #include "autofs_i.h"
15
autofs_new_ino(struct autofs_sb_info * sbi)16 struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi)
17 {
18 struct autofs_info *ino;
19
20 ino = kzalloc(sizeof(*ino), GFP_KERNEL);
21 if (ino) {
22 INIT_LIST_HEAD(&ino->active);
23 INIT_LIST_HEAD(&ino->expiring);
24 ino->last_used = jiffies;
25 ino->sbi = sbi;
26 }
27 return ino;
28 }
29
autofs_clean_ino(struct autofs_info * ino)30 void autofs_clean_ino(struct autofs_info *ino)
31 {
32 ino->uid = GLOBAL_ROOT_UID;
33 ino->gid = GLOBAL_ROOT_GID;
34 ino->last_used = jiffies;
35 }
36
autofs_free_ino(struct autofs_info * ino)37 void autofs_free_ino(struct autofs_info *ino)
38 {
39 kfree(ino);
40 }
41
autofs_kill_sb(struct super_block * sb)42 void autofs_kill_sb(struct super_block *sb)
43 {
44 struct autofs_sb_info *sbi = autofs_sbi(sb);
45
46 /*
47 * In the event of a failure in get_sb_nodev the superblock
48 * info is not present so nothing else has been setup, so
49 * just call kill_anon_super when we are called from
50 * deactivate_super.
51 */
52 if (sbi) {
53 /* Free wait queues, close pipe */
54 autofs_catatonic_mode(sbi);
55 put_pid(sbi->oz_pgrp);
56 }
57
58 pr_debug("shutting down\n");
59 kill_litter_super(sb);
60 if (sbi)
61 kfree_rcu(sbi, rcu);
62 }
63
autofs_show_options(struct seq_file * m,struct dentry * root)64 static int autofs_show_options(struct seq_file *m, struct dentry *root)
65 {
66 struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
67 struct inode *root_inode = d_inode(root->d_sb->s_root);
68
69 if (!sbi)
70 return 0;
71
72 seq_printf(m, ",fd=%d", sbi->pipefd);
73 if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
74 seq_printf(m, ",uid=%u",
75 from_kuid_munged(&init_user_ns, root_inode->i_uid));
76 if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
77 seq_printf(m, ",gid=%u",
78 from_kgid_munged(&init_user_ns, root_inode->i_gid));
79 seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp));
80 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
81 seq_printf(m, ",minproto=%d", sbi->min_proto);
82 seq_printf(m, ",maxproto=%d", sbi->max_proto);
83
84 if (autofs_type_offset(sbi->type))
85 seq_printf(m, ",offset");
86 else if (autofs_type_direct(sbi->type))
87 seq_printf(m, ",direct");
88 else
89 seq_printf(m, ",indirect");
90 #ifdef CONFIG_CHECKPOINT_RESTORE
91 if (sbi->pipe)
92 seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
93 else
94 seq_printf(m, ",pipe_ino=-1");
95 #endif
96 return 0;
97 }
98
autofs_evict_inode(struct inode * inode)99 static void autofs_evict_inode(struct inode *inode)
100 {
101 clear_inode(inode);
102 kfree(inode->i_private);
103 }
104
105 static const struct super_operations autofs_sops = {
106 .statfs = simple_statfs,
107 .show_options = autofs_show_options,
108 .evict_inode = autofs_evict_inode,
109 };
110
111 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
112 Opt_indirect, Opt_direct, Opt_offset};
113
114 static const match_table_t tokens = {
115 {Opt_fd, "fd=%u"},
116 {Opt_uid, "uid=%u"},
117 {Opt_gid, "gid=%u"},
118 {Opt_pgrp, "pgrp=%u"},
119 {Opt_minproto, "minproto=%u"},
120 {Opt_maxproto, "maxproto=%u"},
121 {Opt_indirect, "indirect"},
122 {Opt_direct, "direct"},
123 {Opt_offset, "offset"},
124 {Opt_err, NULL}
125 };
126
parse_options(char * options,int * pipefd,kuid_t * uid,kgid_t * gid,int * pgrp,bool * pgrp_set,unsigned int * type,int * minproto,int * maxproto)127 static int parse_options(char *options, int *pipefd, kuid_t *uid, kgid_t *gid,
128 int *pgrp, bool *pgrp_set, unsigned int *type,
129 int *minproto, int *maxproto)
130 {
131 char *p;
132 substring_t args[MAX_OPT_ARGS];
133 int option;
134
135 *uid = current_uid();
136 *gid = current_gid();
137
138 *minproto = AUTOFS_MIN_PROTO_VERSION;
139 *maxproto = AUTOFS_MAX_PROTO_VERSION;
140
141 *pipefd = -1;
142
143 if (!options)
144 return 1;
145
146 while ((p = strsep(&options, ",")) != NULL) {
147 int token;
148
149 if (!*p)
150 continue;
151
152 token = match_token(p, tokens, args);
153 switch (token) {
154 case Opt_fd:
155 if (match_int(args, pipefd))
156 return 1;
157 break;
158 case Opt_uid:
159 if (match_int(args, &option))
160 return 1;
161 *uid = make_kuid(current_user_ns(), option);
162 if (!uid_valid(*uid))
163 return 1;
164 break;
165 case Opt_gid:
166 if (match_int(args, &option))
167 return 1;
168 *gid = make_kgid(current_user_ns(), option);
169 if (!gid_valid(*gid))
170 return 1;
171 break;
172 case Opt_pgrp:
173 if (match_int(args, &option))
174 return 1;
175 *pgrp = option;
176 *pgrp_set = true;
177 break;
178 case Opt_minproto:
179 if (match_int(args, &option))
180 return 1;
181 *minproto = option;
182 break;
183 case Opt_maxproto:
184 if (match_int(args, &option))
185 return 1;
186 *maxproto = option;
187 break;
188 case Opt_indirect:
189 set_autofs_type_indirect(type);
190 break;
191 case Opt_direct:
192 set_autofs_type_direct(type);
193 break;
194 case Opt_offset:
195 set_autofs_type_offset(type);
196 break;
197 default:
198 return 1;
199 }
200 }
201 return (*pipefd < 0);
202 }
203
autofs_fill_super(struct super_block * s,void * data,int silent)204 int autofs_fill_super(struct super_block *s, void *data, int silent)
205 {
206 struct inode *root_inode;
207 struct dentry *root;
208 struct file *pipe;
209 int pipefd;
210 struct autofs_sb_info *sbi;
211 struct autofs_info *ino;
212 int pgrp = 0;
213 bool pgrp_set = false;
214 int ret = -EINVAL;
215
216 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
217 if (!sbi)
218 return -ENOMEM;
219 pr_debug("starting up, sbi = %p\n", sbi);
220
221 s->s_fs_info = sbi;
222 sbi->magic = AUTOFS_SBI_MAGIC;
223 sbi->pipefd = -1;
224 sbi->pipe = NULL;
225 sbi->catatonic = 1;
226 sbi->exp_timeout = 0;
227 sbi->oz_pgrp = NULL;
228 sbi->sb = s;
229 sbi->version = 0;
230 sbi->sub_version = 0;
231 set_autofs_type_indirect(&sbi->type);
232 sbi->min_proto = 0;
233 sbi->max_proto = 0;
234 mutex_init(&sbi->wq_mutex);
235 mutex_init(&sbi->pipe_mutex);
236 spin_lock_init(&sbi->fs_lock);
237 sbi->queues = NULL;
238 spin_lock_init(&sbi->lookup_lock);
239 INIT_LIST_HEAD(&sbi->active_list);
240 INIT_LIST_HEAD(&sbi->expiring_list);
241 s->s_blocksize = 1024;
242 s->s_blocksize_bits = 10;
243 s->s_magic = AUTOFS_SUPER_MAGIC;
244 s->s_op = &autofs_sops;
245 s->s_d_op = &autofs_dentry_operations;
246 s->s_time_gran = 1;
247
248 /*
249 * Get the root inode and dentry, but defer checking for errors.
250 */
251 ino = autofs_new_ino(sbi);
252 if (!ino) {
253 ret = -ENOMEM;
254 goto fail_free;
255 }
256 root_inode = autofs_get_inode(s, S_IFDIR | 0755);
257 root = d_make_root(root_inode);
258 if (!root) {
259 ret = -ENOMEM;
260 goto fail_ino;
261 }
262 pipe = NULL;
263
264 root->d_fsdata = ino;
265
266 /* Can this call block? */
267 if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
268 &pgrp, &pgrp_set, &sbi->type, &sbi->min_proto,
269 &sbi->max_proto)) {
270 pr_err("called with bogus options\n");
271 goto fail_dput;
272 }
273
274 /* Test versions first */
275 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
276 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
277 pr_err("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 if (pgrp_set) {
292 sbi->oz_pgrp = find_get_pid(pgrp);
293 if (!sbi->oz_pgrp) {
294 pr_err("could not find process group %d\n",
295 pgrp);
296 goto fail_dput;
297 }
298 } else {
299 sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
300 }
301
302 if (autofs_type_trigger(sbi->type))
303 __managed_dentry_set_managed(root);
304
305 root_inode->i_fop = &autofs_root_operations;
306 root_inode->i_op = &autofs_dir_inode_operations;
307
308 pr_debug("pipe fd = %d, pgrp = %u\n", pipefd, pid_nr(sbi->oz_pgrp));
309 pipe = fget(pipefd);
310
311 if (!pipe) {
312 pr_err("could not open pipe file descriptor\n");
313 goto fail_put_pid;
314 }
315 ret = autofs_prepare_pipe(pipe);
316 if (ret < 0)
317 goto fail_fput;
318 sbi->pipe = pipe;
319 sbi->pipefd = pipefd;
320 sbi->catatonic = 0;
321
322 /*
323 * Success! Install the root dentry now to indicate completion.
324 */
325 s->s_root = root;
326 return 0;
327
328 /*
329 * Failure ... clean up.
330 */
331 fail_fput:
332 pr_err("pipe file descriptor does not contain proper ops\n");
333 fput(pipe);
334 fail_put_pid:
335 put_pid(sbi->oz_pgrp);
336 fail_dput:
337 dput(root);
338 goto fail_free;
339 fail_ino:
340 autofs_free_ino(ino);
341 fail_free:
342 kfree(sbi);
343 s->s_fs_info = NULL;
344 return ret;
345 }
346
autofs_get_inode(struct super_block * sb,umode_t mode)347 struct inode *autofs_get_inode(struct super_block *sb, umode_t mode)
348 {
349 struct inode *inode = new_inode(sb);
350
351 if (inode == NULL)
352 return NULL;
353
354 inode->i_mode = mode;
355 if (sb->s_root) {
356 inode->i_uid = d_inode(sb->s_root)->i_uid;
357 inode->i_gid = d_inode(sb->s_root)->i_gid;
358 }
359 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
360 inode->i_ino = get_next_ino();
361
362 if (S_ISDIR(mode)) {
363 set_nlink(inode, 2);
364 inode->i_op = &autofs_dir_inode_operations;
365 inode->i_fop = &autofs_dir_operations;
366 } else if (S_ISLNK(mode)) {
367 inode->i_op = &autofs_symlink_inode_operations;
368 } else
369 WARN_ON(1);
370
371 return inode;
372 }
373