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Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[karo-tx-linux.git] / fs / autofs / inode.c
1 /* -*- linux-c -*- --------------------------------------------------------- *
2  *
3  * linux/fs/autofs/inode.c
4  *
5  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6  *
7  * This file is part of the Linux kernel and is made available under
8  * the terms of the GNU General Public License, version 2, or at your
9  * option, any later version, incorporated herein by reference.
10  *
11  * ------------------------------------------------------------------------- */
12
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/slab.h>
16 #include <linux/file.h>
17 #include <linux/parser.h>
18 #include <linux/bitops.h>
19 #include <linux/magic.h>
20 #include "autofs_i.h"
21 #include <linux/module.h>
22
23 void autofs_kill_sb(struct super_block *sb)
24 {
25         struct autofs_sb_info *sbi = autofs_sbi(sb);
26         unsigned int n;
27
28         /*
29          * In the event of a failure in get_sb_nodev the superblock
30          * info is not present so nothing else has been setup, so
31          * just call kill_anon_super when we are called from
32          * deactivate_super.
33          */
34         if (!sbi)
35                 goto out_kill_sb;
36
37         if (!sbi->catatonic)
38                 autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
39
40         put_pid(sbi->oz_pgrp);
41
42         autofs_hash_nuke(sbi);
43         for (n = 0; n < AUTOFS_MAX_SYMLINKS; n++) {
44                 if (test_bit(n, sbi->symlink_bitmap))
45                         kfree(sbi->symlink[n].data);
46         }
47
48         kfree(sb->s_fs_info);
49
50 out_kill_sb:
51         DPRINTK(("autofs: shutting down\n"));
52         kill_anon_super(sb);
53 }
54
55 static const struct super_operations autofs_sops = {
56         .statfs         = simple_statfs,
57         .show_options   = generic_show_options,
58 };
59
60 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
61
62 static match_table_t autofs_tokens = {
63         {Opt_fd, "fd=%u"},
64         {Opt_uid, "uid=%u"},
65         {Opt_gid, "gid=%u"},
66         {Opt_pgrp, "pgrp=%u"},
67         {Opt_minproto, "minproto=%u"},
68         {Opt_maxproto, "maxproto=%u"},
69         {Opt_err, NULL}
70 };
71
72 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
73                 pid_t *pgrp, int *minproto, int *maxproto)
74 {
75         char *p;
76         substring_t args[MAX_OPT_ARGS];
77         int option;
78
79         *uid = current->uid;
80         *gid = current->gid;
81         *pgrp = task_pgrp_nr(current);
82
83         *minproto = *maxproto = AUTOFS_PROTO_VERSION;
84
85         *pipefd = -1;
86
87         if (!options)
88                 return 1;
89
90         while ((p = strsep(&options, ",")) != NULL) {
91                 int token;
92                 if (!*p)
93                         continue;
94
95                 token = match_token(p, autofs_tokens, args);
96                 switch (token) {
97                 case Opt_fd:
98                         if (match_int(&args[0], &option))
99                                 return 1;
100                         *pipefd = option;
101                         break;
102                 case Opt_uid:
103                         if (match_int(&args[0], &option))
104                                 return 1;
105                         *uid = option;
106                         break;
107                 case Opt_gid:
108                         if (match_int(&args[0], &option))
109                                 return 1;
110                         *gid = option;
111                         break;
112                 case Opt_pgrp:
113                         if (match_int(&args[0], &option))
114                                 return 1;
115                         *pgrp = option;
116                         break;
117                 case Opt_minproto:
118                         if (match_int(&args[0], &option))
119                                 return 1;
120                         *minproto = option;
121                         break;
122                 case Opt_maxproto:
123                         if (match_int(&args[0], &option))
124                                 return 1;
125                         *maxproto = option;
126                         break;
127                 default:
128                         return 1;
129                 }
130         }
131         return (*pipefd < 0);
132 }
133
134 int autofs_fill_super(struct super_block *s, void *data, int silent)
135 {
136         struct inode * root_inode;
137         struct dentry * root;
138         struct file * pipe;
139         int pipefd;
140         struct autofs_sb_info *sbi;
141         int minproto, maxproto;
142         pid_t pgid;
143
144         save_mount_options(s, data);
145
146         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
147         if (!sbi)
148                 goto fail_unlock;
149         DPRINTK(("autofs: starting up, sbi = %p\n",sbi));
150
151         s->s_fs_info = sbi;
152         sbi->magic = AUTOFS_SBI_MAGIC;
153         sbi->pipe = NULL;
154         sbi->catatonic = 1;
155         sbi->exp_timeout = 0;
156         autofs_initialize_hash(&sbi->dirhash);
157         sbi->queues = NULL;
158         memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
159         sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
160         s->s_blocksize = 1024;
161         s->s_blocksize_bits = 10;
162         s->s_magic = AUTOFS_SUPER_MAGIC;
163         s->s_op = &autofs_sops;
164         s->s_time_gran = 1;
165         sbi->sb = s;
166
167         root_inode = autofs_iget(s, AUTOFS_ROOT_INO);
168         if (IS_ERR(root_inode))
169                 goto fail_free;
170         root = d_alloc_root(root_inode);
171         pipe = NULL;
172
173         if (!root)
174                 goto fail_iput;
175
176         /* Can this call block?  - WTF cares? s is locked. */
177         if (parse_options(data, &pipefd, &root_inode->i_uid,
178                                 &root_inode->i_gid, &pgid, &minproto,
179                                 &maxproto)) {
180                 printk("autofs: called with bogus options\n");
181                 goto fail_dput;
182         }
183
184         /* Couldn't this be tested earlier? */
185         if (minproto > AUTOFS_PROTO_VERSION ||
186              maxproto < AUTOFS_PROTO_VERSION) {
187                 printk("autofs: kernel does not match daemon version\n");
188                 goto fail_dput;
189         }
190
191         DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, pgid));
192         sbi->oz_pgrp = find_get_pid(pgid);
193
194         if (!sbi->oz_pgrp) {
195                 printk("autofs: could not find process group %d\n", pgid);
196                 goto fail_dput;
197         }
198
199         pipe = fget(pipefd);
200         
201         if (!pipe) {
202                 printk("autofs: could not open pipe file descriptor\n");
203                 goto fail_put_pid;
204         }
205
206         if (!pipe->f_op || !pipe->f_op->write)
207                 goto fail_fput;
208         sbi->pipe = pipe;
209         sbi->catatonic = 0;
210
211         /*
212          * Success! Install the root dentry now to indicate completion.
213          */
214         s->s_root = root;
215         return 0;
216
217 fail_fput:
218         printk("autofs: pipe file descriptor does not contain proper ops\n");
219         fput(pipe);
220 fail_put_pid:
221         put_pid(sbi->oz_pgrp);
222 fail_dput:
223         dput(root);
224         goto fail_free;
225 fail_iput:
226         printk("autofs: get root dentry failed\n");
227         iput(root_inode);
228 fail_free:
229         kfree(sbi);
230         s->s_fs_info = NULL;
231 fail_unlock:
232         return -EINVAL;
233 }
234
235 struct inode *autofs_iget(struct super_block *sb, unsigned long ino)
236 {
237         unsigned int n;
238         struct autofs_sb_info *sbi = autofs_sbi(sb);
239         struct inode *inode;
240
241         inode = iget_locked(sb, ino);
242         if (!inode)
243                 return ERR_PTR(-ENOMEM);
244         if (!(inode->i_state & I_NEW))
245                 return inode;
246
247         /* Initialize to the default case (stub directory) */
248
249         inode->i_op = &simple_dir_inode_operations;
250         inode->i_fop = &simple_dir_operations;
251         inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
252         inode->i_nlink = 2;
253         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
254         inode->i_blocks = 0;
255
256         if (ino == AUTOFS_ROOT_INO) {
257                 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
258                 inode->i_op = &autofs_root_inode_operations;
259                 inode->i_fop = &autofs_root_operations;
260                 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
261                 goto done;
262         } 
263         
264         inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
265         inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
266         
267         if (ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO) {
268                 /* Symlink inode - should be in symlink list */
269                 struct autofs_symlink *sl;
270
271                 n = ino - AUTOFS_FIRST_SYMLINK;
272                 if (n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
273                         printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
274                         goto done;
275                 }
276                 
277                 inode->i_op = &autofs_symlink_inode_operations;
278                 sl = &sbi->symlink[n];
279                 inode->i_private = sl;
280                 inode->i_mode = S_IFLNK | S_IRWXUGO;
281                 inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
282                 inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
283                 inode->i_size = sl->len;
284                 inode->i_nlink = 1;
285         }
286
287 done:
288         unlock_new_inode(inode);
289         return inode;
290 }