Merge branch 'master' into gfs2
[linux-2.6] / 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 static void autofs_put_super(struct super_block *sb)
24 {
25         struct autofs_sb_info *sbi = autofs_sbi(sb);
26         unsigned int n;
27
28         if ( !sbi->catatonic )
29                 autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
30
31         autofs_hash_nuke(sbi);
32         for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
33                 if ( test_bit(n, sbi->symlink_bitmap) )
34                         kfree(sbi->symlink[n].data);
35         }
36
37         kfree(sb->s_fs_info);
38
39         DPRINTK(("autofs: shutting down\n"));
40 }
41
42 static void autofs_read_inode(struct inode *inode);
43
44 static struct super_operations autofs_sops = {
45         .read_inode     = autofs_read_inode,
46         .put_super      = autofs_put_super,
47         .statfs         = simple_statfs,
48 };
49
50 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
51
52 static match_table_t autofs_tokens = {
53         {Opt_fd, "fd=%u"},
54         {Opt_uid, "uid=%u"},
55         {Opt_gid, "gid=%u"},
56         {Opt_pgrp, "pgrp=%u"},
57         {Opt_minproto, "minproto=%u"},
58         {Opt_maxproto, "maxproto=%u"},
59         {Opt_err, NULL}
60 };
61
62 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto)
63 {
64         char *p;
65         substring_t args[MAX_OPT_ARGS];
66         int option;
67
68         *uid = current->uid;
69         *gid = current->gid;
70         *pgrp = process_group(current);
71
72         *minproto = *maxproto = AUTOFS_PROTO_VERSION;
73
74         *pipefd = -1;
75
76         if (!options)
77                 return 1;
78
79         while ((p = strsep(&options, ",")) != NULL) {
80                 int token;
81                 if (!*p)
82                         continue;
83
84                 token = match_token(p, autofs_tokens, args);
85                 switch (token) {
86                 case Opt_fd:
87                         if (match_int(&args[0], &option))
88                                 return 1;
89                         *pipefd = option;
90                         break;
91                 case Opt_uid:
92                         if (match_int(&args[0], &option))
93                                 return 1;
94                         *uid = option;
95                         break;
96                 case Opt_gid:
97                         if (match_int(&args[0], &option))
98                                 return 1;
99                         *gid = option;
100                         break;
101                 case Opt_pgrp:
102                         if (match_int(&args[0], &option))
103                                 return 1;
104                         *pgrp = option;
105                         break;
106                 case Opt_minproto:
107                         if (match_int(&args[0], &option))
108                                 return 1;
109                         *minproto = option;
110                         break;
111                 case Opt_maxproto:
112                         if (match_int(&args[0], &option))
113                                 return 1;
114                         *maxproto = option;
115                         break;
116                 default:
117                         return 1;
118                 }
119         }
120         return (*pipefd < 0);
121 }
122
123 int autofs_fill_super(struct super_block *s, void *data, int silent)
124 {
125         struct inode * root_inode;
126         struct dentry * root;
127         struct file * pipe;
128         int pipefd;
129         struct autofs_sb_info *sbi;
130         int minproto, maxproto;
131
132         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
133         if ( !sbi )
134                 goto fail_unlock;
135         DPRINTK(("autofs: starting up, sbi = %p\n",sbi));
136
137         s->s_fs_info = sbi;
138         sbi->magic = AUTOFS_SBI_MAGIC;
139         sbi->catatonic = 0;
140         sbi->exp_timeout = 0;
141         sbi->oz_pgrp = process_group(current);
142         autofs_initialize_hash(&sbi->dirhash);
143         sbi->queues = NULL;
144         memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
145         sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
146         s->s_blocksize = 1024;
147         s->s_blocksize_bits = 10;
148         s->s_magic = AUTOFS_SUPER_MAGIC;
149         s->s_op = &autofs_sops;
150         s->s_time_gran = 1;
151         sbi->sb = s;
152
153         root_inode = iget(s, AUTOFS_ROOT_INO);
154         root = d_alloc_root(root_inode);
155         pipe = NULL;
156
157         if (!root)
158                 goto fail_iput;
159
160         /* Can this call block?  - WTF cares? s is locked. */
161         if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) {
162                 printk("autofs: called with bogus options\n");
163                 goto fail_dput;
164         }
165
166         /* Couldn't this be tested earlier? */
167         if ( minproto > AUTOFS_PROTO_VERSION || 
168              maxproto < AUTOFS_PROTO_VERSION ) {
169                 printk("autofs: kernel does not match daemon version\n");
170                 goto fail_dput;
171         }
172
173         DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
174         pipe = fget(pipefd);
175         
176         if ( !pipe ) {
177                 printk("autofs: could not open pipe file descriptor\n");
178                 goto fail_dput;
179         }
180         if ( !pipe->f_op || !pipe->f_op->write )
181                 goto fail_fput;
182         sbi->pipe = pipe;
183
184         /*
185          * Success! Install the root dentry now to indicate completion.
186          */
187         s->s_root = root;
188         return 0;
189
190 fail_fput:
191         printk("autofs: pipe file descriptor does not contain proper ops\n");
192         fput(pipe);
193 fail_dput:
194         dput(root);
195         goto fail_free;
196 fail_iput:
197         printk("autofs: get root dentry failed\n");
198         iput(root_inode);
199 fail_free:
200         kfree(sbi);
201 fail_unlock:
202         return -EINVAL;
203 }
204
205 static void autofs_read_inode(struct inode *inode)
206 {
207         ino_t ino = inode->i_ino;
208         unsigned int n;
209         struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
210
211         /* Initialize to the default case (stub directory) */
212
213         inode->i_op = &simple_dir_inode_operations;
214         inode->i_fop = &simple_dir_operations;
215         inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
216         inode->i_nlink = 2;
217         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
218         inode->i_blocks = 0;
219
220         if ( ino == AUTOFS_ROOT_INO ) {
221                 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
222                 inode->i_op = &autofs_root_inode_operations;
223                 inode->i_fop = &autofs_root_operations;
224                 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
225                 return;
226         } 
227         
228         inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
229         inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
230         
231         if ( ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO ) {
232                 /* Symlink inode - should be in symlink list */
233                 struct autofs_symlink *sl;
234
235                 n = ino - AUTOFS_FIRST_SYMLINK;
236                 if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
237                         printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
238                         return;
239                 }
240                 
241                 inode->i_op = &autofs_symlink_inode_operations;
242                 sl = &sbi->symlink[n];
243                 inode->i_private = sl;
244                 inode->i_mode = S_IFLNK | S_IRWXUGO;
245                 inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
246                 inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
247                 inode->i_size = sl->len;
248                 inode->i_nlink = 1;
249         }
250 }