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 const 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 } 291