Merge git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / 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/smp_lock.h>
22 #include <linux/magic.h>
23 #include "autofs_i.h"
24 #include <linux/module.h>
25
26 static void ino_lnkfree(struct autofs_info *ino)
27 {
28         kfree(ino->u.symlink);
29         ino->u.symlink = NULL;
30 }
31
32 struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
33                                      struct autofs_sb_info *sbi, mode_t mode)
34 {
35         int reinit = 1;
36
37         if (ino == NULL) {
38                 reinit = 0;
39                 ino = kmalloc(sizeof(*ino), GFP_KERNEL);
40         }
41
42         if (ino == NULL)
43                 return NULL;
44
45         ino->flags = 0;
46         ino->mode = mode;
47         ino->inode = NULL;
48         ino->dentry = NULL;
49         ino->size = 0;
50
51         ino->last_used = jiffies;
52         atomic_set(&ino->count, 0);
53
54         ino->sbi = sbi;
55
56         if (reinit && ino->free)
57                 (ino->free)(ino);
58
59         memset(&ino->u, 0, sizeof(ino->u));
60
61         ino->free = NULL;
62
63         if (S_ISLNK(mode))
64                 ino->free = ino_lnkfree;
65
66         return ino;
67 }
68
69 void autofs4_free_ino(struct autofs_info *ino)
70 {
71         struct autofs_info *p_ino;
72
73         if (ino->dentry) {
74                 ino->dentry->d_fsdata = NULL;
75                 if (ino->dentry->d_inode) {
76                         struct dentry *parent = ino->dentry->d_parent;
77                         if (atomic_dec_and_test(&ino->count)) {
78                                 p_ino = autofs4_dentry_ino(parent);
79                                 if (p_ino && parent != ino->dentry)
80                                         atomic_dec(&p_ino->count);
81                         }
82                         dput(ino->dentry);
83                 }
84                 ino->dentry = NULL;
85         }
86         if (ino->free)
87                 (ino->free)(ino);
88         kfree(ino);
89 }
90
91 /*
92  * Deal with the infamous "Busy inodes after umount ..." message.
93  *
94  * Clean up the dentry tree. This happens with autofs if the user
95  * space program goes away due to a SIGKILL, SIGSEGV etc.
96  */
97 static void autofs4_force_release(struct autofs_sb_info *sbi)
98 {
99         struct dentry *this_parent = sbi->sb->s_root;
100         struct list_head *next;
101
102         spin_lock(&dcache_lock);
103 repeat:
104         next = this_parent->d_subdirs.next;
105 resume:
106         while (next != &this_parent->d_subdirs) {
107                 struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
108
109                 /* Negative dentry - don`t care */
110                 if (!simple_positive(dentry)) {
111                         next = next->next;
112                         continue;
113                 }
114
115                 if (!list_empty(&dentry->d_subdirs)) {
116                         this_parent = dentry;
117                         goto repeat;
118                 }
119
120                 next = next->next;
121                 spin_unlock(&dcache_lock);
122
123                 DPRINTK("dentry %p %.*s",
124                         dentry, (int)dentry->d_name.len, dentry->d_name.name);
125
126                 dput(dentry);
127                 spin_lock(&dcache_lock);
128         }
129
130         if (this_parent != sbi->sb->s_root) {
131                 struct dentry *dentry = this_parent;
132
133                 next = this_parent->d_u.d_child.next;
134                 this_parent = this_parent->d_parent;
135                 spin_unlock(&dcache_lock);
136                 DPRINTK("parent dentry %p %.*s",
137                         dentry, (int)dentry->d_name.len, dentry->d_name.name);
138                 dput(dentry);
139                 spin_lock(&dcache_lock);
140                 goto resume;
141         }
142         spin_unlock(&dcache_lock);
143 }
144
145 void autofs4_kill_sb(struct super_block *sb)
146 {
147         struct autofs_sb_info *sbi = autofs4_sbi(sb);
148
149         sb->s_fs_info = NULL;
150
151         if ( !sbi->catatonic )
152                 autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */
153
154         /* Clean up and release dangling references */
155         autofs4_force_release(sbi);
156
157         kfree(sbi);
158
159         DPRINTK("shutting down");
160         kill_anon_super(sb);
161 }
162
163 static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
164 {
165         struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);
166
167         if (!sbi)
168                 return 0;
169
170         seq_printf(m, ",fd=%d", sbi->pipefd);
171         seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
172         seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
173         seq_printf(m, ",minproto=%d", sbi->min_proto);
174         seq_printf(m, ",maxproto=%d", sbi->max_proto);
175
176         if (sbi->type & AUTOFS_TYPE_OFFSET)
177                 seq_printf(m, ",offset");
178         else if (sbi->type & AUTOFS_TYPE_DIRECT)
179                 seq_printf(m, ",direct");
180         else
181                 seq_printf(m, ",indirect");
182
183         return 0;
184 }
185
186 static struct super_operations autofs4_sops = {
187         .statfs         = simple_statfs,
188         .show_options   = autofs4_show_options,
189 };
190
191 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
192         Opt_indirect, Opt_direct, Opt_offset};
193
194 static match_table_t tokens = {
195         {Opt_fd, "fd=%u"},
196         {Opt_uid, "uid=%u"},
197         {Opt_gid, "gid=%u"},
198         {Opt_pgrp, "pgrp=%u"},
199         {Opt_minproto, "minproto=%u"},
200         {Opt_maxproto, "maxproto=%u"},
201         {Opt_indirect, "indirect"},
202         {Opt_direct, "direct"},
203         {Opt_offset, "offset"},
204         {Opt_err, NULL}
205 };
206
207 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
208                          pid_t *pgrp, unsigned int *type,
209                          int *minproto, int *maxproto)
210 {
211         char *p;
212         substring_t args[MAX_OPT_ARGS];
213         int option;
214
215         *uid = current->uid;
216         *gid = current->gid;
217         *pgrp = process_group(current);
218
219         *minproto = AUTOFS_MIN_PROTO_VERSION;
220         *maxproto = AUTOFS_MAX_PROTO_VERSION;
221
222         *pipefd = -1;
223
224         if (!options)
225                 return 1;
226
227         while ((p = strsep(&options, ",")) != NULL) {
228                 int token;
229                 if (!*p)
230                         continue;
231
232                 token = match_token(p, tokens, args);
233                 switch (token) {
234                 case Opt_fd:
235                         if (match_int(args, pipefd))
236                                 return 1;
237                         break;
238                 case Opt_uid:
239                         if (match_int(args, &option))
240                                 return 1;
241                         *uid = option;
242                         break;
243                 case Opt_gid:
244                         if (match_int(args, &option))
245                                 return 1;
246                         *gid = option;
247                         break;
248                 case Opt_pgrp:
249                         if (match_int(args, &option))
250                                 return 1;
251                         *pgrp = option;
252                         break;
253                 case Opt_minproto:
254                         if (match_int(args, &option))
255                                 return 1;
256                         *minproto = option;
257                         break;
258                 case Opt_maxproto:
259                         if (match_int(args, &option))
260                                 return 1;
261                         *maxproto = option;
262                         break;
263                 case Opt_indirect:
264                         *type = AUTOFS_TYPE_INDIRECT;
265                         break;
266                 case Opt_direct:
267                         *type = AUTOFS_TYPE_DIRECT;
268                         break;
269                 case Opt_offset:
270                         *type = AUTOFS_TYPE_DIRECT | AUTOFS_TYPE_OFFSET;
271                         break;
272                 default:
273                         return 1;
274                 }
275         }
276         return (*pipefd < 0);
277 }
278
279 static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
280 {
281         struct autofs_info *ino;
282
283         ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
284         if (!ino)
285                 return NULL;
286
287         return ino;
288 }
289
290 static struct dentry_operations autofs4_sb_dentry_operations = {
291         .d_release      = autofs4_dentry_release,
292 };
293
294 int autofs4_fill_super(struct super_block *s, void *data, int silent)
295 {
296         struct inode * root_inode;
297         struct dentry * root;
298         struct file * pipe;
299         int pipefd;
300         struct autofs_sb_info *sbi;
301         struct autofs_info *ino;
302
303         sbi = (struct autofs_sb_info *) kmalloc(sizeof(*sbi), GFP_KERNEL);
304         if ( !sbi )
305                 goto fail_unlock;
306         DPRINTK("starting up, sbi = %p",sbi);
307
308         memset(sbi, 0, sizeof(*sbi));
309
310         s->s_fs_info = sbi;
311         sbi->magic = AUTOFS_SBI_MAGIC;
312         sbi->pipefd = -1;
313         sbi->catatonic = 0;
314         sbi->exp_timeout = 0;
315         sbi->oz_pgrp = process_group(current);
316         sbi->sb = s;
317         sbi->version = 0;
318         sbi->sub_version = 0;
319         sbi->type = 0;
320         sbi->min_proto = 0;
321         sbi->max_proto = 0;
322         mutex_init(&sbi->wq_mutex);
323         spin_lock_init(&sbi->fs_lock);
324         sbi->queues = NULL;
325         s->s_blocksize = 1024;
326         s->s_blocksize_bits = 10;
327         s->s_magic = AUTOFS_SUPER_MAGIC;
328         s->s_op = &autofs4_sops;
329         s->s_time_gran = 1;
330
331         /*
332          * Get the root inode and dentry, but defer checking for errors.
333          */
334         ino = autofs4_mkroot(sbi);
335         if (!ino)
336                 goto fail_free;
337         root_inode = autofs4_get_inode(s, ino);
338         if (!root_inode)
339                 goto fail_ino;
340
341         root = d_alloc_root(root_inode);
342         if (!root)
343                 goto fail_iput;
344         pipe = NULL;
345
346         root->d_op = &autofs4_sb_dentry_operations;
347         root->d_fsdata = ino;
348
349         /* Can this call block? */
350         if (parse_options(data, &pipefd,
351                           &root_inode->i_uid, &root_inode->i_gid,
352                           &sbi->oz_pgrp, &sbi->type,
353                           &sbi->min_proto, &sbi->max_proto)) {
354                 printk("autofs: called with bogus options\n");
355                 goto fail_dput;
356         }
357
358         root_inode->i_fop = &autofs4_root_operations;
359         root_inode->i_op = sbi->type & AUTOFS_TYPE_DIRECT ?
360                         &autofs4_direct_root_inode_operations :
361                         &autofs4_indirect_root_inode_operations;
362
363         /* Couldn't this be tested earlier? */
364         if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
365             sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
366                 printk("autofs: kernel does not match daemon version "
367                        "daemon (%d, %d) kernel (%d, %d)\n",
368                         sbi->min_proto, sbi->max_proto,
369                         AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
370                 goto fail_dput;
371         }
372
373         /* Establish highest kernel protocol version */
374         if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
375                 sbi->version = AUTOFS_MAX_PROTO_VERSION;
376         else
377                 sbi->version = sbi->max_proto;
378         sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
379
380         DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
381         pipe = fget(pipefd);
382         
383         if ( !pipe ) {
384                 printk("autofs: could not open pipe file descriptor\n");
385                 goto fail_dput;
386         }
387         if ( !pipe->f_op || !pipe->f_op->write )
388                 goto fail_fput;
389         sbi->pipe = pipe;
390         sbi->pipefd = pipefd;
391
392         /*
393          * Success! Install the root dentry now to indicate completion.
394          */
395         s->s_root = root;
396         return 0;
397         
398         /*
399          * Failure ... clean up.
400          */
401 fail_fput:
402         printk("autofs: pipe file descriptor does not contain proper ops\n");
403         fput(pipe);
404         /* fall through */
405 fail_dput:
406         dput(root);
407         goto fail_free;
408 fail_iput:
409         printk("autofs: get root dentry failed\n");
410         iput(root_inode);
411 fail_ino:
412         kfree(ino);
413 fail_free:
414         kfree(sbi);
415 fail_unlock:
416         return -EINVAL;
417 }
418
419 struct inode *autofs4_get_inode(struct super_block *sb,
420                                 struct autofs_info *inf)
421 {
422         struct inode *inode = new_inode(sb);
423
424         if (inode == NULL)
425                 return NULL;
426
427         inf->inode = inode;
428         inode->i_mode = inf->mode;
429         if (sb->s_root) {
430                 inode->i_uid = sb->s_root->d_inode->i_uid;
431                 inode->i_gid = sb->s_root->d_inode->i_gid;
432         } else {
433                 inode->i_uid = 0;
434                 inode->i_gid = 0;
435         }
436         inode->i_blocks = 0;
437         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
438
439         if (S_ISDIR(inf->mode)) {
440                 inode->i_nlink = 2;
441                 inode->i_op = &autofs4_dir_inode_operations;
442                 inode->i_fop = &autofs4_dir_operations;
443         } else if (S_ISLNK(inf->mode)) {
444                 inode->i_size = inf->size;
445                 inode->i_op = &autofs4_symlink_inode_operations;
446         }
447
448         return inode;
449 }