ocfs2: bump version number
[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/magic.h>
22 #include "autofs_i.h"
23 #include <linux/module.h>
24
25 static void ino_lnkfree(struct autofs_info *ino)
26 {
27         kfree(ino->u.symlink);
28         ino->u.symlink = NULL;
29 }
30
31 struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
32                                      struct autofs_sb_info *sbi, mode_t mode)
33 {
34         int reinit = 1;
35
36         if (ino == NULL) {
37                 reinit = 0;
38                 ino = kmalloc(sizeof(*ino), GFP_KERNEL);
39         }
40
41         if (ino == NULL)
42                 return NULL;
43
44         ino->flags = 0;
45         ino->mode = mode;
46         ino->inode = NULL;
47         ino->dentry = NULL;
48         ino->size = 0;
49
50         INIT_LIST_HEAD(&ino->rehash);
51
52         ino->last_used = jiffies;
53         atomic_set(&ino->count, 0);
54
55         ino->sbi = sbi;
56
57         if (reinit && ino->free)
58                 (ino->free)(ino);
59
60         memset(&ino->u, 0, sizeof(ino->u));
61
62         ino->free = NULL;
63
64         if (S_ISLNK(mode))
65                 ino->free = ino_lnkfree;
66
67         return ino;
68 }
69
70 void autofs4_free_ino(struct autofs_info *ino)
71 {
72         struct autofs_info *p_ino;
73
74         if (ino->dentry) {
75                 ino->dentry->d_fsdata = NULL;
76                 if (ino->dentry->d_inode) {
77                         struct dentry *parent = ino->dentry->d_parent;
78                         if (atomic_dec_and_test(&ino->count)) {
79                                 p_ino = autofs4_dentry_ino(parent);
80                                 if (p_ino && parent != ino->dentry)
81                                         atomic_dec(&p_ino->count);
82                         }
83                         dput(ino->dentry);
84                 }
85                 ino->dentry = NULL;
86         }
87         if (ino->free)
88                 (ino->free)(ino);
89         kfree(ino);
90 }
91
92 /*
93  * Deal with the infamous "Busy inodes after umount ..." message.
94  *
95  * Clean up the dentry tree. This happens with autofs if the user
96  * space program goes away due to a SIGKILL, SIGSEGV etc.
97  */
98 static void autofs4_force_release(struct autofs_sb_info *sbi)
99 {
100         struct dentry *this_parent = sbi->sb->s_root;
101         struct list_head *next;
102
103         if (!sbi->sb->s_root)
104                 return;
105
106         spin_lock(&dcache_lock);
107 repeat:
108         next = this_parent->d_subdirs.next;
109 resume:
110         while (next != &this_parent->d_subdirs) {
111                 struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
112
113                 /* Negative dentry - don`t care */
114                 if (!simple_positive(dentry)) {
115                         next = next->next;
116                         continue;
117                 }
118
119                 if (!list_empty(&dentry->d_subdirs)) {
120                         this_parent = dentry;
121                         goto repeat;
122                 }
123
124                 next = next->next;
125                 spin_unlock(&dcache_lock);
126
127                 DPRINTK("dentry %p %.*s",
128                         dentry, (int)dentry->d_name.len, dentry->d_name.name);
129
130                 dput(dentry);
131                 spin_lock(&dcache_lock);
132         }
133
134         if (this_parent != sbi->sb->s_root) {
135                 struct dentry *dentry = this_parent;
136
137                 next = this_parent->d_u.d_child.next;
138                 this_parent = this_parent->d_parent;
139                 spin_unlock(&dcache_lock);
140                 DPRINTK("parent dentry %p %.*s",
141                         dentry, (int)dentry->d_name.len, dentry->d_name.name);
142                 dput(dentry);
143                 spin_lock(&dcache_lock);
144                 goto resume;
145         }
146         spin_unlock(&dcache_lock);
147 }
148
149 void autofs4_kill_sb(struct super_block *sb)
150 {
151         struct autofs_sb_info *sbi = autofs4_sbi(sb);
152
153         /*
154          * In the event of a failure in get_sb_nodev the superblock
155          * info is not present so nothing else has been setup, so
156          * just call kill_anon_super when we are called from
157          * deactivate_super.
158          */
159         if (!sbi)
160                 goto out_kill_sb;
161
162         if (!sbi->catatonic)
163                 autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */
164
165         /* Clean up and release dangling references */
166         autofs4_force_release(sbi);
167
168         sb->s_fs_info = NULL;
169         kfree(sbi);
170
171 out_kill_sb:
172         DPRINTK("shutting down");
173         kill_anon_super(sb);
174 }
175
176 static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
177 {
178         struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);
179
180         if (!sbi)
181                 return 0;
182
183         seq_printf(m, ",fd=%d", sbi->pipefd);
184         seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
185         seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
186         seq_printf(m, ",minproto=%d", sbi->min_proto);
187         seq_printf(m, ",maxproto=%d", sbi->max_proto);
188
189         if (sbi->type & AUTOFS_TYPE_OFFSET)
190                 seq_printf(m, ",offset");
191         else if (sbi->type & AUTOFS_TYPE_DIRECT)
192                 seq_printf(m, ",direct");
193         else
194                 seq_printf(m, ",indirect");
195
196         return 0;
197 }
198
199 static const struct super_operations autofs4_sops = {
200         .statfs         = simple_statfs,
201         .show_options   = autofs4_show_options,
202 };
203
204 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
205         Opt_indirect, Opt_direct, Opt_offset};
206
207 static match_table_t tokens = {
208         {Opt_fd, "fd=%u"},
209         {Opt_uid, "uid=%u"},
210         {Opt_gid, "gid=%u"},
211         {Opt_pgrp, "pgrp=%u"},
212         {Opt_minproto, "minproto=%u"},
213         {Opt_maxproto, "maxproto=%u"},
214         {Opt_indirect, "indirect"},
215         {Opt_direct, "direct"},
216         {Opt_offset, "offset"},
217         {Opt_err, NULL}
218 };
219
220 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
221                 pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto)
222 {
223         char *p;
224         substring_t args[MAX_OPT_ARGS];
225         int option;
226
227         *uid = current->uid;
228         *gid = current->gid;
229         *pgrp = task_pgrp_nr(current);
230
231         *minproto = AUTOFS_MIN_PROTO_VERSION;
232         *maxproto = AUTOFS_MAX_PROTO_VERSION;
233
234         *pipefd = -1;
235
236         if (!options)
237                 return 1;
238
239         while ((p = strsep(&options, ",")) != NULL) {
240                 int token;
241                 if (!*p)
242                         continue;
243
244                 token = match_token(p, tokens, args);
245                 switch (token) {
246                 case Opt_fd:
247                         if (match_int(args, pipefd))
248                                 return 1;
249                         break;
250                 case Opt_uid:
251                         if (match_int(args, &option))
252                                 return 1;
253                         *uid = option;
254                         break;
255                 case Opt_gid:
256                         if (match_int(args, &option))
257                                 return 1;
258                         *gid = option;
259                         break;
260                 case Opt_pgrp:
261                         if (match_int(args, &option))
262                                 return 1;
263                         *pgrp = option;
264                         break;
265                 case Opt_minproto:
266                         if (match_int(args, &option))
267                                 return 1;
268                         *minproto = option;
269                         break;
270                 case Opt_maxproto:
271                         if (match_int(args, &option))
272                                 return 1;
273                         *maxproto = option;
274                         break;
275                 case Opt_indirect:
276                         *type = AUTOFS_TYPE_INDIRECT;
277                         break;
278                 case Opt_direct:
279                         *type = AUTOFS_TYPE_DIRECT;
280                         break;
281                 case Opt_offset:
282                         *type = AUTOFS_TYPE_DIRECT | AUTOFS_TYPE_OFFSET;
283                         break;
284                 default:
285                         return 1;
286                 }
287         }
288         return (*pipefd < 0);
289 }
290
291 static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
292 {
293         struct autofs_info *ino;
294
295         ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
296         if (!ino)
297                 return NULL;
298
299         return ino;
300 }
301
302 static struct dentry_operations autofs4_sb_dentry_operations = {
303         .d_release      = autofs4_dentry_release,
304 };
305
306 int autofs4_fill_super(struct super_block *s, void *data, int silent)
307 {
308         struct inode * root_inode;
309         struct dentry * root;
310         struct file * pipe;
311         int pipefd;
312         struct autofs_sb_info *sbi;
313         struct autofs_info *ino;
314
315         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
316         if (!sbi)
317                 goto fail_unlock;
318         DPRINTK("starting up, sbi = %p",sbi);
319
320         s->s_fs_info = sbi;
321         sbi->magic = AUTOFS_SBI_MAGIC;
322         sbi->pipefd = -1;
323         sbi->pipe = NULL;
324         sbi->catatonic = 1;
325         sbi->exp_timeout = 0;
326         sbi->oz_pgrp = task_pgrp_nr(current);
327         sbi->sb = s;
328         sbi->version = 0;
329         sbi->sub_version = 0;
330         sbi->type = 0;
331         sbi->min_proto = 0;
332         sbi->max_proto = 0;
333         mutex_init(&sbi->wq_mutex);
334         spin_lock_init(&sbi->fs_lock);
335         sbi->queues = NULL;
336         spin_lock_init(&sbi->rehash_lock);
337         INIT_LIST_HEAD(&sbi->rehash_list);
338         s->s_blocksize = 1024;
339         s->s_blocksize_bits = 10;
340         s->s_magic = AUTOFS_SUPER_MAGIC;
341         s->s_op = &autofs4_sops;
342         s->s_time_gran = 1;
343
344         /*
345          * Get the root inode and dentry, but defer checking for errors.
346          */
347         ino = autofs4_mkroot(sbi);
348         if (!ino)
349                 goto fail_free;
350         root_inode = autofs4_get_inode(s, ino);
351         if (!root_inode)
352                 goto fail_ino;
353
354         root = d_alloc_root(root_inode);
355         if (!root)
356                 goto fail_iput;
357         pipe = NULL;
358
359         root->d_op = &autofs4_sb_dentry_operations;
360         root->d_fsdata = ino;
361
362         /* Can this call block? */
363         if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
364                                 &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
365                                 &sbi->max_proto)) {
366                 printk("autofs: called with bogus options\n");
367                 goto fail_dput;
368         }
369
370         root_inode->i_fop = &autofs4_root_operations;
371         root_inode->i_op = sbi->type & AUTOFS_TYPE_DIRECT ?
372                         &autofs4_direct_root_inode_operations :
373                         &autofs4_indirect_root_inode_operations;
374
375         /* Couldn't this be tested earlier? */
376         if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
377             sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
378                 printk("autofs: kernel does not match daemon version "
379                        "daemon (%d, %d) kernel (%d, %d)\n",
380                         sbi->min_proto, sbi->max_proto,
381                         AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
382                 goto fail_dput;
383         }
384
385         /* Establish highest kernel protocol version */
386         if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
387                 sbi->version = AUTOFS_MAX_PROTO_VERSION;
388         else
389                 sbi->version = sbi->max_proto;
390         sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
391
392         DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
393         pipe = fget(pipefd);
394         
395         if (!pipe) {
396                 printk("autofs: could not open pipe file descriptor\n");
397                 goto fail_dput;
398         }
399         if (!pipe->f_op || !pipe->f_op->write)
400                 goto fail_fput;
401         sbi->pipe = pipe;
402         sbi->pipefd = pipefd;
403         sbi->catatonic = 0;
404
405         /*
406          * Success! Install the root dentry now to indicate completion.
407          */
408         s->s_root = root;
409         return 0;
410         
411         /*
412          * Failure ... clean up.
413          */
414 fail_fput:
415         printk("autofs: pipe file descriptor does not contain proper ops\n");
416         fput(pipe);
417         /* fall through */
418 fail_dput:
419         dput(root);
420         goto fail_free;
421 fail_iput:
422         printk("autofs: get root dentry failed\n");
423         iput(root_inode);
424 fail_ino:
425         kfree(ino);
426 fail_free:
427         kfree(sbi);
428         s->s_fs_info = NULL;
429 fail_unlock:
430         return -EINVAL;
431 }
432
433 struct inode *autofs4_get_inode(struct super_block *sb,
434                                 struct autofs_info *inf)
435 {
436         struct inode *inode = new_inode(sb);
437
438         if (inode == NULL)
439                 return NULL;
440
441         inf->inode = inode;
442         inode->i_mode = inf->mode;
443         if (sb->s_root) {
444                 inode->i_uid = sb->s_root->d_inode->i_uid;
445                 inode->i_gid = sb->s_root->d_inode->i_gid;
446         } else {
447                 inode->i_uid = 0;
448                 inode->i_gid = 0;
449         }
450         inode->i_blocks = 0;
451         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
452
453         if (S_ISDIR(inf->mode)) {
454                 inode->i_nlink = 2;
455                 inode->i_op = &autofs4_dir_inode_operations;
456                 inode->i_fop = &autofs4_dir_operations;
457         } else if (S_ISLNK(inf->mode)) {
458                 inode->i_size = inf->size;
459                 inode->i_op = &autofs4_symlink_inode_operations;
460         }
461
462         return inode;
463 }