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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[karo-tx-linux.git] / fs / autofs4 / inode.c
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/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/file.h>
13 #include <linux/seq_file.h>
14 #include <linux/pagemap.h>
15 #include <linux/parser.h>
16 #include <linux/bitops.h>
17 #include <linux/magic.h>
18 #include "autofs_i.h"
19 #include <linux/module.h>
20
21 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *sbi)
22 {
23         struct autofs_info *ino;
24
25         ino = kzalloc(sizeof(*ino), GFP_KERNEL);
26         if (ino) {
27                 INIT_LIST_HEAD(&ino->active);
28                 INIT_LIST_HEAD(&ino->expiring);
29                 ino->last_used = jiffies;
30                 ino->sbi = sbi;
31         }
32         return ino;
33 }
34
35 void autofs4_clean_ino(struct autofs_info *ino)
36 {
37         ino->uid = GLOBAL_ROOT_UID;
38         ino->gid = GLOBAL_ROOT_GID;
39         ino->last_used = jiffies;
40 }
41
42 void autofs4_free_ino(struct autofs_info *ino)
43 {
44         kfree(ino);
45 }
46
47 void autofs4_kill_sb(struct super_block *sb)
48 {
49         struct autofs_sb_info *sbi = autofs4_sbi(sb);
50
51         /*
52          * In the event of a failure in get_sb_nodev the superblock
53          * info is not present so nothing else has been setup, so
54          * just call kill_anon_super when we are called from
55          * deactivate_super.
56          */
57         if (sbi) {
58                 /* Free wait queues, close pipe */
59                 autofs4_catatonic_mode(sbi);
60                 put_pid(sbi->oz_pgrp);
61         }
62
63         pr_debug("shutting down\n");
64         kill_litter_super(sb);
65         if (sbi)
66                 kfree_rcu(sbi, rcu);
67 }
68
69 static int autofs4_show_options(struct seq_file *m, struct dentry *root)
70 {
71         struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
72         struct inode *root_inode = d_inode(root->d_sb->s_root);
73
74         if (!sbi)
75                 return 0;
76
77         seq_printf(m, ",fd=%d", sbi->pipefd);
78         if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
79                 seq_printf(m, ",uid=%u",
80                         from_kuid_munged(&init_user_ns, root_inode->i_uid));
81         if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
82                 seq_printf(m, ",gid=%u",
83                         from_kgid_munged(&init_user_ns, root_inode->i_gid));
84         seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp));
85         seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
86         seq_printf(m, ",minproto=%d", sbi->min_proto);
87         seq_printf(m, ",maxproto=%d", sbi->max_proto);
88
89         if (autofs_type_offset(sbi->type))
90                 seq_printf(m, ",offset");
91         else if (autofs_type_direct(sbi->type))
92                 seq_printf(m, ",direct");
93         else
94                 seq_printf(m, ",indirect");
95 #ifdef CONFIG_CHECKPOINT_RESTORE
96         if (sbi->pipe)
97                 seq_printf(m, ",pipe_ino=%ld", sbi->pipe->f_inode->i_ino);
98         else
99                 seq_printf(m, ",pipe_ino=-1");
100 #endif
101         return 0;
102 }
103
104 static void autofs4_evict_inode(struct inode *inode)
105 {
106         clear_inode(inode);
107         kfree(inode->i_private);
108 }
109
110 static const struct super_operations autofs4_sops = {
111         .statfs         = simple_statfs,
112         .show_options   = autofs4_show_options,
113         .evict_inode    = autofs4_evict_inode,
114 };
115
116 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
117         Opt_indirect, Opt_direct, Opt_offset};
118
119 static const match_table_t tokens = {
120         {Opt_fd, "fd=%u"},
121         {Opt_uid, "uid=%u"},
122         {Opt_gid, "gid=%u"},
123         {Opt_pgrp, "pgrp=%u"},
124         {Opt_minproto, "minproto=%u"},
125         {Opt_maxproto, "maxproto=%u"},
126         {Opt_indirect, "indirect"},
127         {Opt_direct, "direct"},
128         {Opt_offset, "offset"},
129         {Opt_err, NULL}
130 };
131
132 static int parse_options(char *options, int *pipefd, kuid_t *uid, kgid_t *gid,
133                          int *pgrp, bool *pgrp_set, unsigned int *type,
134                          int *minproto, int *maxproto)
135 {
136         char *p;
137         substring_t args[MAX_OPT_ARGS];
138         int option;
139
140         *uid = current_uid();
141         *gid = current_gid();
142
143         *minproto = AUTOFS_MIN_PROTO_VERSION;
144         *maxproto = AUTOFS_MAX_PROTO_VERSION;
145
146         *pipefd = -1;
147
148         if (!options)
149                 return 1;
150
151         while ((p = strsep(&options, ",")) != NULL) {
152                 int token;
153
154                 if (!*p)
155                         continue;
156
157                 token = match_token(p, tokens, args);
158                 switch (token) {
159                 case Opt_fd:
160                         if (match_int(args, pipefd))
161                                 return 1;
162                         break;
163                 case Opt_uid:
164                         if (match_int(args, &option))
165                                 return 1;
166                         *uid = make_kuid(current_user_ns(), option);
167                         if (!uid_valid(*uid))
168                                 return 1;
169                         break;
170                 case Opt_gid:
171                         if (match_int(args, &option))
172                                 return 1;
173                         *gid = make_kgid(current_user_ns(), option);
174                         if (!gid_valid(*gid))
175                                 return 1;
176                         break;
177                 case Opt_pgrp:
178                         if (match_int(args, &option))
179                                 return 1;
180                         *pgrp = option;
181                         *pgrp_set = true;
182                         break;
183                 case Opt_minproto:
184                         if (match_int(args, &option))
185                                 return 1;
186                         *minproto = option;
187                         break;
188                 case Opt_maxproto:
189                         if (match_int(args, &option))
190                                 return 1;
191                         *maxproto = option;
192                         break;
193                 case Opt_indirect:
194                         set_autofs_type_indirect(type);
195                         break;
196                 case Opt_direct:
197                         set_autofs_type_direct(type);
198                         break;
199                 case Opt_offset:
200                         set_autofs_type_offset(type);
201                         break;
202                 default:
203                         return 1;
204                 }
205         }
206         return (*pipefd < 0);
207 }
208
209 int autofs4_fill_super(struct super_block *s, void *data, int silent)
210 {
211         struct inode *root_inode;
212         struct dentry *root;
213         struct file *pipe;
214         int pipefd;
215         struct autofs_sb_info *sbi;
216         struct autofs_info *ino;
217         int pgrp = 0;
218         bool pgrp_set = false;
219         int ret = -EINVAL;
220
221         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
222         if (!sbi)
223                 return -ENOMEM;
224         pr_debug("starting up, sbi = %p\n", sbi);
225
226         s->s_fs_info = sbi;
227         sbi->magic = AUTOFS_SBI_MAGIC;
228         sbi->pipefd = -1;
229         sbi->pipe = NULL;
230         sbi->catatonic = 1;
231         sbi->exp_timeout = 0;
232         sbi->oz_pgrp = NULL;
233         sbi->sb = s;
234         sbi->version = 0;
235         sbi->sub_version = 0;
236         set_autofs_type_indirect(&sbi->type);
237         sbi->min_proto = 0;
238         sbi->max_proto = 0;
239         mutex_init(&sbi->wq_mutex);
240         mutex_init(&sbi->pipe_mutex);
241         spin_lock_init(&sbi->fs_lock);
242         sbi->queues = NULL;
243         spin_lock_init(&sbi->lookup_lock);
244         INIT_LIST_HEAD(&sbi->active_list);
245         INIT_LIST_HEAD(&sbi->expiring_list);
246         s->s_blocksize = 1024;
247         s->s_blocksize_bits = 10;
248         s->s_magic = AUTOFS_SUPER_MAGIC;
249         s->s_op = &autofs4_sops;
250         s->s_d_op = &autofs4_dentry_operations;
251         s->s_time_gran = 1;
252
253         /*
254          * Get the root inode and dentry, but defer checking for errors.
255          */
256         ino = autofs4_new_ino(sbi);
257         if (!ino) {
258                 ret = -ENOMEM;
259                 goto fail_free;
260         }
261         root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
262         root = d_make_root(root_inode);
263         if (!root)
264                 goto fail_ino;
265         pipe = NULL;
266
267         root->d_fsdata = ino;
268
269         /* Can this call block? */
270         if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
271                           &pgrp, &pgrp_set, &sbi->type, &sbi->min_proto,
272                           &sbi->max_proto)) {
273                 pr_err("called with bogus options\n");
274                 goto fail_dput;
275         }
276
277         if (pgrp_set) {
278                 sbi->oz_pgrp = find_get_pid(pgrp);
279                 if (!sbi->oz_pgrp) {
280                         pr_err("could not find process group %d\n",
281                                 pgrp);
282                         goto fail_dput;
283                 }
284         } else {
285                 sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
286         }
287
288         if (autofs_type_trigger(sbi->type))
289                 __managed_dentry_set_managed(root);
290
291         root_inode->i_fop = &autofs4_root_operations;
292         root_inode->i_op = &autofs4_dir_inode_operations;
293
294         /* Couldn't this be tested earlier? */
295         if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
296             sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
297                 pr_err("kernel does not match daemon version "
298                        "daemon (%d, %d) kernel (%d, %d)\n",
299                        sbi->min_proto, sbi->max_proto,
300                        AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
301                 goto fail_dput;
302         }
303
304         /* Establish highest kernel protocol version */
305         if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
306                 sbi->version = AUTOFS_MAX_PROTO_VERSION;
307         else
308                 sbi->version = sbi->max_proto;
309         sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
310
311         pr_debug("pipe fd = %d, pgrp = %u\n", pipefd, pid_nr(sbi->oz_pgrp));
312         pipe = fget(pipefd);
313
314         if (!pipe) {
315                 pr_err("could not open pipe file descriptor\n");
316                 goto fail_dput;
317         }
318         ret = autofs_prepare_pipe(pipe);
319         if (ret < 0)
320                 goto fail_fput;
321         sbi->pipe = pipe;
322         sbi->pipefd = pipefd;
323         sbi->catatonic = 0;
324
325         /*
326          * Success! Install the root dentry now to indicate completion.
327          */
328         s->s_root = root;
329         return 0;
330
331         /*
332          * Failure ... clean up.
333          */
334 fail_fput:
335         pr_err("pipe file descriptor does not contain proper ops\n");
336         fput(pipe);
337         /* fall through */
338 fail_dput:
339         dput(root);
340         goto fail_free;
341 fail_ino:
342         kfree(ino);
343 fail_free:
344         put_pid(sbi->oz_pgrp);
345         kfree(sbi);
346         s->s_fs_info = NULL;
347         return ret;
348 }
349
350 struct inode *autofs4_get_inode(struct super_block *sb, umode_t mode)
351 {
352         struct inode *inode = new_inode(sb);
353
354         if (inode == NULL)
355                 return NULL;
356
357         inode->i_mode = mode;
358         if (sb->s_root) {
359                 inode->i_uid = d_inode(sb->s_root)->i_uid;
360                 inode->i_gid = d_inode(sb->s_root)->i_gid;
361         }
362         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
363         inode->i_ino = get_next_ino();
364
365         if (S_ISDIR(mode)) {
366                 set_nlink(inode, 2);
367                 inode->i_op = &autofs4_dir_inode_operations;
368                 inode->i_fop = &autofs4_dir_operations;
369         } else if (S_ISLNK(mode)) {
370                 inode->i_op = &autofs4_symlink_inode_operations;
371         }
372
373         return inode;
374 }