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 autofs_hash_nuke(sbi); 41 for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) { 42 if ( test_bit(n, sbi->symlink_bitmap) ) 43 kfree(sbi->symlink[n].data); 44 } 45 46 kfree(sb->s_fs_info); 47 48 out_kill_sb: 49 DPRINTK(("autofs: shutting down\n")); 50 kill_anon_super(sb); 51 } 52 53 static void autofs_read_inode(struct inode *inode); 54 55 static const struct super_operations autofs_sops = { 56 .read_inode = autofs_read_inode, 57 .statfs = simple_statfs, 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, pid_t *pgrp, int *minproto, int *maxproto) 73 { 74 char *p; 75 substring_t args[MAX_OPT_ARGS]; 76 int option; 77 78 *uid = current->uid; 79 *gid = current->gid; 80 *pgrp = process_group(current); 81 82 *minproto = *maxproto = AUTOFS_PROTO_VERSION; 83 84 *pipefd = -1; 85 86 if (!options) 87 return 1; 88 89 while ((p = strsep(&options, ",")) != NULL) { 90 int token; 91 if (!*p) 92 continue; 93 94 token = match_token(p, autofs_tokens, args); 95 switch (token) { 96 case Opt_fd: 97 if (match_int(&args[0], &option)) 98 return 1; 99 *pipefd = option; 100 break; 101 case Opt_uid: 102 if (match_int(&args[0], &option)) 103 return 1; 104 *uid = option; 105 break; 106 case Opt_gid: 107 if (match_int(&args[0], &option)) 108 return 1; 109 *gid = option; 110 break; 111 case Opt_pgrp: 112 if (match_int(&args[0], &option)) 113 return 1; 114 *pgrp = option; 115 break; 116 case Opt_minproto: 117 if (match_int(&args[0], &option)) 118 return 1; 119 *minproto = option; 120 break; 121 case Opt_maxproto: 122 if (match_int(&args[0], &option)) 123 return 1; 124 *maxproto = option; 125 break; 126 default: 127 return 1; 128 } 129 } 130 return (*pipefd < 0); 131 } 132 133 int autofs_fill_super(struct super_block *s, void *data, int silent) 134 { 135 struct inode * root_inode; 136 struct dentry * root; 137 struct file * pipe; 138 int pipefd; 139 struct autofs_sb_info *sbi; 140 int minproto, maxproto; 141 142 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 143 if ( !sbi ) 144 goto fail_unlock; 145 DPRINTK(("autofs: starting up, sbi = %p\n",sbi)); 146 147 s->s_fs_info = sbi; 148 sbi->magic = AUTOFS_SBI_MAGIC; 149 sbi->pipe = NULL; 150 sbi->catatonic = 1; 151 sbi->exp_timeout = 0; 152 sbi->oz_pgrp = process_group(current); 153 autofs_initialize_hash(&sbi->dirhash); 154 sbi->queues = NULL; 155 memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN); 156 sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO; 157 s->s_blocksize = 1024; 158 s->s_blocksize_bits = 10; 159 s->s_magic = AUTOFS_SUPER_MAGIC; 160 s->s_op = &autofs_sops; 161 s->s_time_gran = 1; 162 sbi->sb = s; 163 164 root_inode = iget(s, AUTOFS_ROOT_INO); 165 root = d_alloc_root(root_inode); 166 pipe = NULL; 167 168 if (!root) 169 goto fail_iput; 170 171 /* Can this call block? - WTF cares? s is locked. */ 172 if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) { 173 printk("autofs: called with bogus options\n"); 174 goto fail_dput; 175 } 176 177 /* Couldn't this be tested earlier? */ 178 if ( minproto > AUTOFS_PROTO_VERSION || 179 maxproto < AUTOFS_PROTO_VERSION ) { 180 printk("autofs: kernel does not match daemon version\n"); 181 goto fail_dput; 182 } 183 184 DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp)); 185 pipe = fget(pipefd); 186 187 if ( !pipe ) { 188 printk("autofs: could not open pipe file descriptor\n"); 189 goto fail_dput; 190 } 191 if ( !pipe->f_op || !pipe->f_op->write ) 192 goto fail_fput; 193 sbi->pipe = pipe; 194 sbi->catatonic = 0; 195 196 /* 197 * Success! Install the root dentry now to indicate completion. 198 */ 199 s->s_root = root; 200 return 0; 201 202 fail_fput: 203 printk("autofs: pipe file descriptor does not contain proper ops\n"); 204 fput(pipe); 205 fail_dput: 206 dput(root); 207 goto fail_free; 208 fail_iput: 209 printk("autofs: get root dentry failed\n"); 210 iput(root_inode); 211 fail_free: 212 kfree(sbi); 213 s->s_fs_info = NULL; 214 fail_unlock: 215 return -EINVAL; 216 } 217 218 static void autofs_read_inode(struct inode *inode) 219 { 220 ino_t ino = inode->i_ino; 221 unsigned int n; 222 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb); 223 224 /* Initialize to the default case (stub directory) */ 225 226 inode->i_op = &simple_dir_inode_operations; 227 inode->i_fop = &simple_dir_operations; 228 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; 229 inode->i_nlink = 2; 230 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 231 inode->i_blocks = 0; 232 233 if ( ino == AUTOFS_ROOT_INO ) { 234 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR; 235 inode->i_op = &autofs_root_inode_operations; 236 inode->i_fop = &autofs_root_operations; 237 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */ 238 return; 239 } 240 241 inode->i_uid = inode->i_sb->s_root->d_inode->i_uid; 242 inode->i_gid = inode->i_sb->s_root->d_inode->i_gid; 243 244 if ( ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO ) { 245 /* Symlink inode - should be in symlink list */ 246 struct autofs_symlink *sl; 247 248 n = ino - AUTOFS_FIRST_SYMLINK; 249 if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) { 250 printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino); 251 return; 252 } 253 254 inode->i_op = &autofs_symlink_inode_operations; 255 sl = &sbi->symlink[n]; 256 inode->i_private = sl; 257 inode->i_mode = S_IFLNK | S_IRWXUGO; 258 inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime; 259 inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 260 inode->i_size = sl->len; 261 inode->i_nlink = 1; 262 } 263 } 264