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/slab.h>
15 #include <linux/file.h>
16 #include <linux/locks.h>
17 #include <asm/bitops.h>
18 #include "autofs_i.h"
19 #define __NO_VERSION__
20 #include <linux/module.h>
21
autofs_put_super(struct super_block * sb)22 static void autofs_put_super(struct super_block *sb)
23 {
24 struct autofs_sb_info *sbi = autofs_sbi(sb);
25 unsigned int n;
26
27 if ( !sbi->catatonic )
28 autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
29
30 autofs_hash_nuke(&sbi->dirhash);
31 for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
32 if ( test_bit(n, sbi->symlink_bitmap) )
33 kfree(sbi->symlink[n].data);
34 }
35
36 kfree(sb->u.generic_sbp);
37
38 DPRINTK(("autofs: shutting down\n"));
39 }
40
41 static int autofs_statfs(struct super_block *sb, struct statfs *buf);
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: autofs_statfs,
48 };
49
parse_options(char * options,int * pipefd,uid_t * uid,gid_t * gid,pid_t * pgrp,int * minproto,int * maxproto)50 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto)
51 {
52 char *this_char, *value;
53
54 *uid = current->uid;
55 *gid = current->gid;
56 *pgrp = current->pgrp;
57
58 *minproto = *maxproto = AUTOFS_PROTO_VERSION;
59
60 *pipefd = -1;
61
62 if ( !options ) return 1;
63 for (this_char = strtok(options,","); this_char; this_char = strtok(NULL,",")) {
64 if ((value = strchr(this_char,'=')) != NULL)
65 *value++ = 0;
66 if (!strcmp(this_char,"fd")) {
67 if (!value || !*value)
68 return 1;
69 *pipefd = simple_strtoul(value,&value,0);
70 if (*value)
71 return 1;
72 }
73 else if (!strcmp(this_char,"uid")) {
74 if (!value || !*value)
75 return 1;
76 *uid = simple_strtoul(value,&value,0);
77 if (*value)
78 return 1;
79 }
80 else if (!strcmp(this_char,"gid")) {
81 if (!value || !*value)
82 return 1;
83 *gid = simple_strtoul(value,&value,0);
84 if (*value)
85 return 1;
86 }
87 else if (!strcmp(this_char,"pgrp")) {
88 if (!value || !*value)
89 return 1;
90 *pgrp = simple_strtoul(value,&value,0);
91 if (*value)
92 return 1;
93 }
94 else if (!strcmp(this_char,"minproto")) {
95 if (!value || !*value)
96 return 1;
97 *minproto = simple_strtoul(value,&value,0);
98 if (*value)
99 return 1;
100 }
101 else if (!strcmp(this_char,"maxproto")) {
102 if (!value || !*value)
103 return 1;
104 *maxproto = simple_strtoul(value,&value,0);
105 if (*value)
106 return 1;
107 }
108 else break;
109 }
110 return (*pipefd < 0);
111 }
112
autofs_read_super(struct super_block * s,void * data,int silent)113 struct super_block *autofs_read_super(struct super_block *s, void *data,
114 int silent)
115 {
116 struct inode * root_inode;
117 struct dentry * root;
118 struct file * pipe;
119 int pipefd;
120 struct autofs_sb_info *sbi;
121 int minproto, maxproto;
122
123 sbi = (struct autofs_sb_info *) kmalloc(sizeof(struct autofs_sb_info), GFP_KERNEL);
124 if ( !sbi )
125 goto fail_unlock;
126 DPRINTK(("autofs: starting up, sbi = %p\n",sbi));
127
128 s->u.generic_sbp = sbi;
129 sbi->magic = AUTOFS_SBI_MAGIC;
130 sbi->catatonic = 0;
131 sbi->exp_timeout = 0;
132 sbi->oz_pgrp = current->pgrp;
133 autofs_initialize_hash(&sbi->dirhash);
134 sbi->queues = NULL;
135 memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
136 sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
137 s->s_blocksize = 1024;
138 s->s_blocksize_bits = 10;
139 s->s_magic = AUTOFS_SUPER_MAGIC;
140 s->s_op = &autofs_sops;
141
142 root_inode = iget(s, AUTOFS_ROOT_INO);
143 root = d_alloc_root(root_inode);
144 pipe = NULL;
145
146 if (!root)
147 goto fail_iput;
148
149 /* Can this call block? - WTF cares? s is locked. */
150 if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) {
151 printk("autofs: called with bogus options\n");
152 goto fail_dput;
153 }
154
155 /* Couldn't this be tested earlier? */
156 if ( minproto > AUTOFS_PROTO_VERSION ||
157 maxproto < AUTOFS_PROTO_VERSION ) {
158 printk("autofs: kernel does not match daemon version\n");
159 goto fail_dput;
160 }
161
162 DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
163 pipe = fget(pipefd);
164
165 if ( !pipe ) {
166 printk("autofs: could not open pipe file descriptor\n");
167 goto fail_dput;
168 }
169 if ( !pipe->f_op || !pipe->f_op->write )
170 goto fail_fput;
171 sbi->pipe = pipe;
172
173 /*
174 * Success! Install the root dentry now to indicate completion.
175 */
176 s->s_root = root;
177 return s;
178
179 fail_fput:
180 printk("autofs: pipe file descriptor does not contain proper ops\n");
181 fput(pipe);
182 fail_dput:
183 dput(root);
184 goto fail_free;
185 fail_iput:
186 printk("autofs: get root dentry failed\n");
187 iput(root_inode);
188 fail_free:
189 kfree(sbi);
190 fail_unlock:
191 return NULL;
192 }
193
autofs_statfs(struct super_block * sb,struct statfs * buf)194 static int autofs_statfs(struct super_block *sb, struct statfs *buf)
195 {
196 buf->f_type = AUTOFS_SUPER_MAGIC;
197 buf->f_bsize = 1024;
198 buf->f_namelen = NAME_MAX;
199 return 0;
200 }
201
autofs_read_inode(struct inode * inode)202 static void autofs_read_inode(struct inode *inode)
203 {
204 ino_t ino = inode->i_ino;
205 unsigned int n;
206 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
207
208 /* Initialize to the default case (stub directory) */
209
210 inode->i_op = &autofs_dir_inode_operations;
211 inode->i_fop = &dcache_dir_ops;
212 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
213 inode->i_nlink = 2;
214 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
215 inode->i_blocks = 0;
216 inode->i_blksize = 1024;
217
218 if ( ino == AUTOFS_ROOT_INO ) {
219 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
220 inode->i_op = &autofs_root_inode_operations;
221 inode->i_fop = &autofs_root_operations;
222 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
223 return;
224 }
225
226 inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
227 inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
228
229 if ( ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO ) {
230 /* Symlink inode - should be in symlink list */
231 struct autofs_symlink *sl;
232
233 n = ino - AUTOFS_FIRST_SYMLINK;
234 if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
235 printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
236 return;
237 }
238
239 inode->i_op = &autofs_symlink_inode_operations;
240 sl = &sbi->symlink[n];
241 inode->u.generic_ip = sl;
242 inode->i_mode = S_IFLNK | S_IRWXUGO;
243 inode->i_mtime = inode->i_ctime = sl->mtime;
244 inode->i_size = sl->len;
245 inode->i_nlink = 1;
246 }
247 }
248