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 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 kill_anon_super(sb); 41 } 42 43 static void autofs_read_inode(struct inode *inode); 44 45 static struct super_operations autofs_sops = { 46 .read_inode = autofs_read_inode, 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 } 251