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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
4 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
5 */
6
7#include <linux/seq_file.h>
8#include <linux/pagemap.h>
9#include <linux/parser.h>
10
11#include "autofs_i.h"
12
13struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi)
14{
15 struct autofs_info *ino;
16
17 ino = kzalloc(sizeof(*ino), GFP_KERNEL);
18 if (ino) {
19 INIT_LIST_HEAD(&ino->active);
20 INIT_LIST_HEAD(&ino->expiring);
21 ino->last_used = jiffies;
22 ino->sbi = sbi;
23 ino->count = 1;
24 }
25 return ino;
26}
27
28void autofs_clean_ino(struct autofs_info *ino)
29{
30 ino->uid = GLOBAL_ROOT_UID;
31 ino->gid = GLOBAL_ROOT_GID;
32 ino->last_used = jiffies;
33}
34
35void autofs_free_ino(struct autofs_info *ino)
36{
37 kfree_rcu(ino, rcu);
38}
39
40void autofs_kill_sb(struct super_block *sb)
41{
42 struct autofs_sb_info *sbi = autofs_sbi(sb);
43
44 /*
45 * In the event of a failure in get_sb_nodev the superblock
46 * info is not present so nothing else has been setup, so
47 * just call kill_anon_super when we are called from
48 * deactivate_super.
49 */
50 if (sbi) {
51 /* Free wait queues, close pipe */
52 autofs_catatonic_mode(sbi);
53 put_pid(sbi->oz_pgrp);
54 }
55
56 pr_debug("shutting down\n");
57 kill_litter_super(sb);
58 if (sbi)
59 kfree_rcu(sbi, rcu);
60}
61
62static int autofs_show_options(struct seq_file *m, struct dentry *root)
63{
64 struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
65 struct inode *root_inode = d_inode(root->d_sb->s_root);
66
67 if (!sbi)
68 return 0;
69
70 seq_printf(m, ",fd=%d", sbi->pipefd);
71 if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
72 seq_printf(m, ",uid=%u",
73 from_kuid_munged(&init_user_ns, root_inode->i_uid));
74 if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
75 seq_printf(m, ",gid=%u",
76 from_kgid_munged(&init_user_ns, root_inode->i_gid));
77 seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp));
78 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
79 seq_printf(m, ",minproto=%d", sbi->min_proto);
80 seq_printf(m, ",maxproto=%d", sbi->max_proto);
81
82 if (autofs_type_offset(sbi->type))
83 seq_puts(m, ",offset");
84 else if (autofs_type_direct(sbi->type))
85 seq_puts(m, ",direct");
86 else
87 seq_puts(m, ",indirect");
88 if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE)
89 seq_puts(m, ",strictexpire");
90 if (sbi->flags & AUTOFS_SBI_IGNORE)
91 seq_puts(m, ",ignore");
92#ifdef CONFIG_CHECKPOINT_RESTORE
93 if (sbi->pipe)
94 seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
95 else
96 seq_puts(m, ",pipe_ino=-1");
97#endif
98 return 0;
99}
100
101static void autofs_evict_inode(struct inode *inode)
102{
103 clear_inode(inode);
104 kfree(inode->i_private);
105}
106
107static const struct super_operations autofs_sops = {
108 .statfs = simple_statfs,
109 .show_options = autofs_show_options,
110 .evict_inode = autofs_evict_inode,
111};
112
113enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
114 Opt_indirect, Opt_direct, Opt_offset, Opt_strictexpire,
115 Opt_ignore};
116
117static 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_strictexpire, "strictexpire"},
128 {Opt_ignore, "ignore"},
129 {Opt_err, NULL}
130};
131
132static int parse_options(char *options,
133 struct inode *root, int *pgrp, bool *pgrp_set,
134 struct autofs_sb_info *sbi)
135{
136 char *p;
137 substring_t args[MAX_OPT_ARGS];
138 int option;
139 int pipefd = -1;
140 kuid_t uid;
141 kgid_t gid;
142
143 root->i_uid = current_uid();
144 root->i_gid = current_gid();
145
146 sbi->min_proto = AUTOFS_MIN_PROTO_VERSION;
147 sbi->max_proto = AUTOFS_MAX_PROTO_VERSION;
148
149 sbi->pipefd = -1;
150
151 if (!options)
152 return 1;
153
154 while ((p = strsep(&options, ",")) != NULL) {
155 int token;
156
157 if (!*p)
158 continue;
159
160 token = match_token(p, tokens, args);
161 switch (token) {
162 case Opt_fd:
163 if (match_int(args, &pipefd))
164 return 1;
165 sbi->pipefd = pipefd;
166 break;
167 case Opt_uid:
168 if (match_int(args, &option))
169 return 1;
170 uid = make_kuid(current_user_ns(), option);
171 if (!uid_valid(uid))
172 return 1;
173 root->i_uid = uid;
174 break;
175 case Opt_gid:
176 if (match_int(args, &option))
177 return 1;
178 gid = make_kgid(current_user_ns(), option);
179 if (!gid_valid(gid))
180 return 1;
181 root->i_gid = gid;
182 break;
183 case Opt_pgrp:
184 if (match_int(args, &option))
185 return 1;
186 *pgrp = option;
187 *pgrp_set = true;
188 break;
189 case Opt_minproto:
190 if (match_int(args, &option))
191 return 1;
192 sbi->min_proto = option;
193 break;
194 case Opt_maxproto:
195 if (match_int(args, &option))
196 return 1;
197 sbi->max_proto = option;
198 break;
199 case Opt_indirect:
200 set_autofs_type_indirect(&sbi->type);
201 break;
202 case Opt_direct:
203 set_autofs_type_direct(&sbi->type);
204 break;
205 case Opt_offset:
206 set_autofs_type_offset(&sbi->type);
207 break;
208 case Opt_strictexpire:
209 sbi->flags |= AUTOFS_SBI_STRICTEXPIRE;
210 break;
211 case Opt_ignore:
212 sbi->flags |= AUTOFS_SBI_IGNORE;
213 break;
214 default:
215 return 1;
216 }
217 }
218 return (sbi->pipefd < 0);
219}
220
221int autofs_fill_super(struct super_block *s, void *data, int silent)
222{
223 struct inode *root_inode;
224 struct dentry *root;
225 struct file *pipe;
226 struct autofs_sb_info *sbi;
227 struct autofs_info *ino;
228 int pgrp = 0;
229 bool pgrp_set = false;
230 int ret = -EINVAL;
231
232 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
233 if (!sbi)
234 return -ENOMEM;
235 pr_debug("starting up, sbi = %p\n", sbi);
236
237 s->s_fs_info = sbi;
238 sbi->magic = AUTOFS_SBI_MAGIC;
239 sbi->pipefd = -1;
240 sbi->pipe = NULL;
241 sbi->exp_timeout = 0;
242 sbi->oz_pgrp = NULL;
243 sbi->sb = s;
244 sbi->version = 0;
245 sbi->sub_version = 0;
246 sbi->flags = AUTOFS_SBI_CATATONIC;
247 set_autofs_type_indirect(&sbi->type);
248 sbi->min_proto = 0;
249 sbi->max_proto = 0;
250 mutex_init(&sbi->wq_mutex);
251 mutex_init(&sbi->pipe_mutex);
252 spin_lock_init(&sbi->fs_lock);
253 sbi->queues = NULL;
254 spin_lock_init(&sbi->lookup_lock);
255 INIT_LIST_HEAD(&sbi->active_list);
256 INIT_LIST_HEAD(&sbi->expiring_list);
257 s->s_blocksize = 1024;
258 s->s_blocksize_bits = 10;
259 s->s_magic = AUTOFS_SUPER_MAGIC;
260 s->s_op = &autofs_sops;
261 s->s_d_op = &autofs_dentry_operations;
262 s->s_time_gran = 1;
263
264 /*
265 * Get the root inode and dentry, but defer checking for errors.
266 */
267 ino = autofs_new_ino(sbi);
268 if (!ino) {
269 ret = -ENOMEM;
270 goto fail_free;
271 }
272 root_inode = autofs_get_inode(s, S_IFDIR | 0755);
273 root = d_make_root(root_inode);
274 if (!root) {
275 ret = -ENOMEM;
276 goto fail_ino;
277 }
278 pipe = NULL;
279
280 root->d_fsdata = ino;
281
282 /* Can this call block? */
283 if (parse_options(data, root_inode, &pgrp, &pgrp_set, sbi)) {
284 pr_err("called with bogus options\n");
285 goto fail_dput;
286 }
287
288 /* Test versions first */
289 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
290 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
291 pr_err("kernel does not match daemon version "
292 "daemon (%d, %d) kernel (%d, %d)\n",
293 sbi->min_proto, sbi->max_proto,
294 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
295 goto fail_dput;
296 }
297
298 /* Establish highest kernel protocol version */
299 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
300 sbi->version = AUTOFS_MAX_PROTO_VERSION;
301 else
302 sbi->version = sbi->max_proto;
303 sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
304
305 if (pgrp_set) {
306 sbi->oz_pgrp = find_get_pid(pgrp);
307 if (!sbi->oz_pgrp) {
308 pr_err("could not find process group %d\n",
309 pgrp);
310 goto fail_dput;
311 }
312 } else {
313 sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
314 }
315
316 if (autofs_type_trigger(sbi->type))
317 __managed_dentry_set_managed(root);
318
319 root_inode->i_fop = &autofs_root_operations;
320 root_inode->i_op = &autofs_dir_inode_operations;
321
322 pr_debug("pipe fd = %d, pgrp = %u\n",
323 sbi->pipefd, pid_nr(sbi->oz_pgrp));
324 pipe = fget(sbi->pipefd);
325
326 if (!pipe) {
327 pr_err("could not open pipe file descriptor\n");
328 goto fail_put_pid;
329 }
330 ret = autofs_prepare_pipe(pipe);
331 if (ret < 0)
332 goto fail_fput;
333 sbi->pipe = pipe;
334 sbi->flags &= ~AUTOFS_SBI_CATATONIC;
335
336 /*
337 * Success! Install the root dentry now to indicate completion.
338 */
339 s->s_root = root;
340 return 0;
341
342 /*
343 * Failure ... clean up.
344 */
345fail_fput:
346 pr_err("pipe file descriptor does not contain proper ops\n");
347 fput(pipe);
348fail_put_pid:
349 put_pid(sbi->oz_pgrp);
350fail_dput:
351 dput(root);
352 goto fail_free;
353fail_ino:
354 autofs_free_ino(ino);
355fail_free:
356 kfree(sbi);
357 s->s_fs_info = NULL;
358 return ret;
359}
360
361struct inode *autofs_get_inode(struct super_block *sb, umode_t mode)
362{
363 struct inode *inode = new_inode(sb);
364
365 if (inode == NULL)
366 return NULL;
367
368 inode->i_mode = mode;
369 if (sb->s_root) {
370 inode->i_uid = d_inode(sb->s_root)->i_uid;
371 inode->i_gid = d_inode(sb->s_root)->i_gid;
372 }
373 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
374 inode->i_ino = get_next_ino();
375
376 if (S_ISDIR(mode)) {
377 set_nlink(inode, 2);
378 inode->i_op = &autofs_dir_inode_operations;
379 inode->i_fop = &autofs_dir_operations;
380 } else if (S_ISLNK(mode)) {
381 inode->i_op = &autofs_symlink_inode_operations;
382 } else
383 WARN_ON(1);
384
385 return inode;
386}