06858d955120ed43fab44309f1bc978f11c24124
[linux-2.6.git] / fs / autofs4 / inode.c
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 <linux/compat.h>
23 #include "autofs_i.h"
24 #include <linux/module.h>
25
26 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *sbi)
27 {
28         struct autofs_info *ino = kzalloc(sizeof(*ino), GFP_KERNEL);
29         if (ino) {
30                 INIT_LIST_HEAD(&ino->active);
31                 INIT_LIST_HEAD(&ino->expiring);
32                 ino->last_used = jiffies;
33                 ino->sbi = sbi;
34         }
35         return ino;
36 }
37
38 void autofs4_clean_ino(struct autofs_info *ino)
39 {
40         ino->uid = 0;
41         ino->gid = 0;
42         ino->last_used = jiffies;
43 }
44
45 void autofs4_free_ino(struct autofs_info *ino)
46 {
47         kfree(ino);
48 }
49
50 void autofs4_kill_sb(struct super_block *sb)
51 {
52         struct autofs_sb_info *sbi = autofs4_sbi(sb);
53
54         /*
55          * In the event of a failure in get_sb_nodev the superblock
56          * info is not present so nothing else has been setup, so
57          * just call kill_anon_super when we are called from
58          * deactivate_super.
59          */
60         if (!sbi)
61                 goto out_kill_sb;
62
63         /* Free wait queues, close pipe */
64         autofs4_catatonic_mode(sbi);
65
66         sb->s_fs_info = NULL;
67         kfree(sbi);
68
69 out_kill_sb:
70         DPRINTK("shutting down");
71         kill_litter_super(sb);
72 }
73
74 static int autofs4_show_options(struct seq_file *m, struct dentry *root)
75 {
76         struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
77         struct inode *root_inode = root->d_sb->s_root->d_inode;
78
79         if (!sbi)
80                 return 0;
81
82         seq_printf(m, ",fd=%d", sbi->pipefd);
83         if (root_inode->i_uid != 0)
84                 seq_printf(m, ",uid=%u", root_inode->i_uid);
85         if (root_inode->i_gid != 0)
86                 seq_printf(m, ",gid=%u", root_inode->i_gid);
87         seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
88         seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
89         seq_printf(m, ",minproto=%d", sbi->min_proto);
90         seq_printf(m, ",maxproto=%d", sbi->max_proto);
91
92         if (autofs_type_offset(sbi->type))
93                 seq_printf(m, ",offset");
94         else if (autofs_type_direct(sbi->type))
95                 seq_printf(m, ",direct");
96         else
97                 seq_printf(m, ",indirect");
98
99         return 0;
100 }
101
102 static void autofs4_evict_inode(struct inode *inode)
103 {
104         end_writeback(inode);
105         kfree(inode->i_private);
106 }
107
108 static const struct super_operations autofs4_sops = {
109         .statfs         = simple_statfs,
110         .show_options   = autofs4_show_options,
111         .evict_inode    = autofs4_evict_inode,
112 };
113
114 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
115         Opt_indirect, Opt_direct, Opt_offset};
116
117 static 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_err, NULL}
128 };
129
130 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
131                 pid_t *pgrp, unsigned int *type, 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         *pgrp = task_pgrp_nr(current);
140
141         *minproto = AUTOFS_MIN_PROTO_VERSION;
142         *maxproto = AUTOFS_MAX_PROTO_VERSION;
143
144         *pipefd = -1;
145
146         if (!options)
147                 return 1;
148
149         while ((p = strsep(&options, ",")) != NULL) {
150                 int token;
151                 if (!*p)
152                         continue;
153
154                 token = match_token(p, tokens, args);
155                 switch (token) {
156                 case Opt_fd:
157                         if (match_int(args, pipefd))
158                                 return 1;
159                         break;
160                 case Opt_uid:
161                         if (match_int(args, &option))
162                                 return 1;
163                         *uid = option;
164                         break;
165                 case Opt_gid:
166                         if (match_int(args, &option))
167                                 return 1;
168                         *gid = option;
169                         break;
170                 case Opt_pgrp:
171                         if (match_int(args, &option))
172                                 return 1;
173                         *pgrp = option;
174                         break;
175                 case Opt_minproto:
176                         if (match_int(args, &option))
177                                 return 1;
178                         *minproto = option;
179                         break;
180                 case Opt_maxproto:
181                         if (match_int(args, &option))
182                                 return 1;
183                         *maxproto = option;
184                         break;
185                 case Opt_indirect:
186                         set_autofs_type_indirect(type);
187                         break;
188                 case Opt_direct:
189                         set_autofs_type_direct(type);
190                         break;
191                 case Opt_offset:
192                         set_autofs_type_offset(type);
193                         break;
194                 default:
195                         return 1;
196                 }
197         }
198         return (*pipefd < 0);
199 }
200
201 int autofs4_fill_super(struct super_block *s, void *data, int silent)
202 {
203         struct inode * root_inode;
204         struct dentry * root;
205         struct file * pipe;
206         int pipefd;
207         struct autofs_sb_info *sbi;
208         struct autofs_info *ino;
209
210         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
211         if (!sbi)
212                 goto fail_unlock;
213         DPRINTK("starting up, sbi = %p",sbi);
214
215         s->s_fs_info = sbi;
216         sbi->magic = AUTOFS_SBI_MAGIC;
217         sbi->pipefd = -1;
218         sbi->pipe = NULL;
219         sbi->catatonic = 1;
220         sbi->exp_timeout = 0;
221         sbi->oz_pgrp = task_pgrp_nr(current);
222         sbi->sb = s;
223         sbi->version = 0;
224         sbi->sub_version = 0;
225         set_autofs_type_indirect(&sbi->type);
226         sbi->min_proto = 0;
227         sbi->max_proto = 0;
228         sbi->compat_daemon = is_compat_task();
229         mutex_init(&sbi->wq_mutex);
230         mutex_init(&sbi->pipe_mutex);
231         spin_lock_init(&sbi->fs_lock);
232         sbi->queues = NULL;
233         spin_lock_init(&sbi->lookup_lock);
234         INIT_LIST_HEAD(&sbi->active_list);
235         INIT_LIST_HEAD(&sbi->expiring_list);
236         s->s_blocksize = 1024;
237         s->s_blocksize_bits = 10;
238         s->s_magic = AUTOFS_SUPER_MAGIC;
239         s->s_op = &autofs4_sops;
240         s->s_d_op = &autofs4_dentry_operations;
241         s->s_time_gran = 1;
242
243         /*
244          * Get the root inode and dentry, but defer checking for errors.
245          */
246         ino = autofs4_new_ino(sbi);
247         if (!ino)
248                 goto fail_free;
249         root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
250         if (!root_inode)
251                 goto fail_ino;
252
253         root = d_alloc_root(root_inode);
254         if (!root)
255                 goto fail_iput;
256         pipe = NULL;
257
258         root->d_fsdata = ino;
259
260         /* Can this call block? */
261         if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
262                                 &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
263                                 &sbi->max_proto)) {
264                 printk("autofs: called with bogus options\n");
265                 goto fail_dput;
266         }
267
268         if (autofs_type_trigger(sbi->type))
269                 __managed_dentry_set_managed(root);
270
271         root_inode->i_fop = &autofs4_root_operations;
272         root_inode->i_op = &autofs4_dir_inode_operations;
273
274         /* Couldn't this be tested earlier? */
275         if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
276             sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
277                 printk("autofs: 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         DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
292         pipe = fget(pipefd);
293         
294         if (!pipe) {
295                 printk("autofs: could not open pipe file descriptor\n");
296                 goto fail_dput;
297         }
298         if (!pipe->f_op || !pipe->f_op->write)
299                 goto fail_fput;
300         sbi->pipe = pipe;
301         sbi->pipefd = pipefd;
302         sbi->catatonic = 0;
303
304         /*
305          * Success! Install the root dentry now to indicate completion.
306          */
307         s->s_root = root;
308         return 0;
309         
310         /*
311          * Failure ... clean up.
312          */
313 fail_fput:
314         printk("autofs: pipe file descriptor does not contain proper ops\n");
315         fput(pipe);
316         /* fall through */
317 fail_dput:
318         dput(root);
319         goto fail_free;
320 fail_iput:
321         printk("autofs: get root dentry failed\n");
322         iput(root_inode);
323 fail_ino:
324         kfree(ino);
325 fail_free:
326         kfree(sbi);
327         s->s_fs_info = NULL;
328 fail_unlock:
329         return -EINVAL;
330 }
331
332 struct inode *autofs4_get_inode(struct super_block *sb, umode_t mode)
333 {
334         struct inode *inode = new_inode(sb);
335
336         if (inode == NULL)
337                 return NULL;
338
339         inode->i_mode = mode;
340         if (sb->s_root) {
341                 inode->i_uid = sb->s_root->d_inode->i_uid;
342                 inode->i_gid = sb->s_root->d_inode->i_gid;
343         }
344         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
345         inode->i_ino = get_next_ino();
346
347         if (S_ISDIR(mode)) {
348                 set_nlink(inode, 2);
349                 inode->i_op = &autofs4_dir_inode_operations;
350                 inode->i_fop = &autofs4_dir_operations;
351         } else if (S_ISLNK(mode)) {
352                 inode->i_op = &autofs4_symlink_inode_operations;
353         }
354
355         return inode;
356 }