1 /* 2 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved 3 * Copyright 2005-2006 Ian Kent <raven@themaw.net> 4 * 5 * This file is part of the Linux kernel and is made available under 6 * the terms of the GNU General Public License, version 2, or at your 7 * option, any later version, incorporated herein by reference. 8 */ 9 10 #include <linux/seq_file.h> 11 #include <linux/pagemap.h> 12 #include <linux/parser.h> 13 14 #include "autofs_i.h" 15 16 struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi) 17 { 18 struct autofs_info *ino; 19 20 ino = kzalloc(sizeof(*ino), GFP_KERNEL); 21 if (ino) { 22 INIT_LIST_HEAD(&ino->active); 23 INIT_LIST_HEAD(&ino->expiring); 24 ino->last_used = jiffies; 25 ino->sbi = sbi; 26 } 27 return ino; 28 } 29 30 void autofs_clean_ino(struct autofs_info *ino) 31 { 32 ino->uid = GLOBAL_ROOT_UID; 33 ino->gid = GLOBAL_ROOT_GID; 34 ino->last_used = jiffies; 35 } 36 37 void autofs_free_ino(struct autofs_info *ino) 38 { 39 kfree_rcu(ino, rcu); 40 } 41 42 void autofs_kill_sb(struct super_block *sb) 43 { 44 struct autofs_sb_info *sbi = autofs_sbi(sb); 45 46 /* 47 * In the event of a failure in get_sb_nodev the superblock 48 * info is not present so nothing else has been setup, so 49 * just call kill_anon_super when we are called from 50 * deactivate_super. 51 */ 52 if (sbi) { 53 /* Free wait queues, close pipe */ 54 autofs_catatonic_mode(sbi); 55 put_pid(sbi->oz_pgrp); 56 } 57 58 pr_debug("shutting down\n"); 59 kill_litter_super(sb); 60 if (sbi) 61 kfree_rcu(sbi, rcu); 62 } 63 64 static int autofs_show_options(struct seq_file *m, struct dentry *root) 65 { 66 struct autofs_sb_info *sbi = autofs_sbi(root->d_sb); 67 struct inode *root_inode = d_inode(root->d_sb->s_root); 68 69 if (!sbi) 70 return 0; 71 72 seq_printf(m, ",fd=%d", sbi->pipefd); 73 if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID)) 74 seq_printf(m, ",uid=%u", 75 from_kuid_munged(&init_user_ns, root_inode->i_uid)); 76 if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID)) 77 seq_printf(m, ",gid=%u", 78 from_kgid_munged(&init_user_ns, root_inode->i_gid)); 79 seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp)); 80 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ); 81 seq_printf(m, ",minproto=%d", sbi->min_proto); 82 seq_printf(m, ",maxproto=%d", sbi->max_proto); 83 84 if (autofs_type_offset(sbi->type)) 85 seq_puts(m, ",offset"); 86 else if (autofs_type_direct(sbi->type)) 87 seq_puts(m, ",direct"); 88 else 89 seq_puts(m, ",indirect"); 90 if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE) 91 seq_puts(m, ",strictexpire"); 92 if (sbi->flags & AUTOFS_SBI_IGNORE) 93 seq_puts(m, ",ignore"); 94 #ifdef CONFIG_CHECKPOINT_RESTORE 95 if (sbi->pipe) 96 seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino); 97 else 98 seq_puts(m, ",pipe_ino=-1"); 99 #endif 100 return 0; 101 } 102 103 static void autofs_evict_inode(struct inode *inode) 104 { 105 clear_inode(inode); 106 kfree(inode->i_private); 107 } 108 109 static const struct super_operations autofs_sops = { 110 .statfs = simple_statfs, 111 .show_options = autofs_show_options, 112 .evict_inode = autofs_evict_inode, 113 }; 114 115 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto, 116 Opt_indirect, Opt_direct, Opt_offset, Opt_strictexpire, 117 Opt_ignore}; 118 119 static const match_table_t tokens = { 120 {Opt_fd, "fd=%u"}, 121 {Opt_uid, "uid=%u"}, 122 {Opt_gid, "gid=%u"}, 123 {Opt_pgrp, "pgrp=%u"}, 124 {Opt_minproto, "minproto=%u"}, 125 {Opt_maxproto, "maxproto=%u"}, 126 {Opt_indirect, "indirect"}, 127 {Opt_direct, "direct"}, 128 {Opt_offset, "offset"}, 129 {Opt_strictexpire, "strictexpire"}, 130 {Opt_ignore, "ignore"}, 131 {Opt_err, NULL} 132 }; 133 134 static int parse_options(char *options, 135 struct inode *root, int *pgrp, bool *pgrp_set, 136 struct autofs_sb_info *sbi) 137 { 138 char *p; 139 substring_t args[MAX_OPT_ARGS]; 140 int option; 141 int pipefd = -1; 142 kuid_t uid; 143 kgid_t gid; 144 145 root->i_uid = current_uid(); 146 root->i_gid = current_gid(); 147 148 sbi->min_proto = AUTOFS_MIN_PROTO_VERSION; 149 sbi->max_proto = AUTOFS_MAX_PROTO_VERSION; 150 151 sbi->pipefd = -1; 152 153 if (!options) 154 return 1; 155 156 while ((p = strsep(&options, ",")) != NULL) { 157 int token; 158 159 if (!*p) 160 continue; 161 162 token = match_token(p, tokens, args); 163 switch (token) { 164 case Opt_fd: 165 if (match_int(args, &pipefd)) 166 return 1; 167 sbi->pipefd = pipefd; 168 break; 169 case Opt_uid: 170 if (match_int(args, &option)) 171 return 1; 172 uid = make_kuid(current_user_ns(), option); 173 if (!uid_valid(uid)) 174 return 1; 175 root->i_uid = uid; 176 break; 177 case Opt_gid: 178 if (match_int(args, &option)) 179 return 1; 180 gid = make_kgid(current_user_ns(), option); 181 if (!gid_valid(gid)) 182 return 1; 183 root->i_gid = gid; 184 break; 185 case Opt_pgrp: 186 if (match_int(args, &option)) 187 return 1; 188 *pgrp = option; 189 *pgrp_set = true; 190 break; 191 case Opt_minproto: 192 if (match_int(args, &option)) 193 return 1; 194 sbi->min_proto = option; 195 break; 196 case Opt_maxproto: 197 if (match_int(args, &option)) 198 return 1; 199 sbi->max_proto = option; 200 break; 201 case Opt_indirect: 202 set_autofs_type_indirect(&sbi->type); 203 break; 204 case Opt_direct: 205 set_autofs_type_direct(&sbi->type); 206 break; 207 case Opt_offset: 208 set_autofs_type_offset(&sbi->type); 209 break; 210 case Opt_strictexpire: 211 sbi->flags |= AUTOFS_SBI_STRICTEXPIRE; 212 break; 213 case Opt_ignore: 214 sbi->flags |= AUTOFS_SBI_IGNORE; 215 break; 216 default: 217 return 1; 218 } 219 } 220 return (sbi->pipefd < 0); 221 } 222 223 int autofs_fill_super(struct super_block *s, void *data, int silent) 224 { 225 struct inode *root_inode; 226 struct dentry *root; 227 struct file *pipe; 228 struct autofs_sb_info *sbi; 229 struct autofs_info *ino; 230 int pgrp = 0; 231 bool pgrp_set = false; 232 int ret = -EINVAL; 233 234 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 235 if (!sbi) 236 return -ENOMEM; 237 pr_debug("starting up, sbi = %p\n", sbi); 238 239 s->s_fs_info = sbi; 240 sbi->magic = AUTOFS_SBI_MAGIC; 241 sbi->pipefd = -1; 242 sbi->pipe = NULL; 243 sbi->exp_timeout = 0; 244 sbi->oz_pgrp = NULL; 245 sbi->sb = s; 246 sbi->version = 0; 247 sbi->sub_version = 0; 248 sbi->flags = AUTOFS_SBI_CATATONIC; 249 set_autofs_type_indirect(&sbi->type); 250 sbi->min_proto = 0; 251 sbi->max_proto = 0; 252 mutex_init(&sbi->wq_mutex); 253 mutex_init(&sbi->pipe_mutex); 254 spin_lock_init(&sbi->fs_lock); 255 sbi->queues = NULL; 256 spin_lock_init(&sbi->lookup_lock); 257 INIT_LIST_HEAD(&sbi->active_list); 258 INIT_LIST_HEAD(&sbi->expiring_list); 259 s->s_blocksize = 1024; 260 s->s_blocksize_bits = 10; 261 s->s_magic = AUTOFS_SUPER_MAGIC; 262 s->s_op = &autofs_sops; 263 s->s_d_op = &autofs_dentry_operations; 264 s->s_time_gran = 1; 265 266 /* 267 * Get the root inode and dentry, but defer checking for errors. 268 */ 269 ino = autofs_new_ino(sbi); 270 if (!ino) { 271 ret = -ENOMEM; 272 goto fail_free; 273 } 274 root_inode = autofs_get_inode(s, S_IFDIR | 0755); 275 root = d_make_root(root_inode); 276 if (!root) { 277 ret = -ENOMEM; 278 goto fail_ino; 279 } 280 pipe = NULL; 281 282 root->d_fsdata = ino; 283 284 /* Can this call block? */ 285 if (parse_options(data, root_inode, &pgrp, &pgrp_set, sbi)) { 286 pr_err("called with bogus options\n"); 287 goto fail_dput; 288 } 289 290 /* Test versions first */ 291 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION || 292 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) { 293 pr_err("kernel does not match daemon version " 294 "daemon (%d, %d) kernel (%d, %d)\n", 295 sbi->min_proto, sbi->max_proto, 296 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); 297 goto fail_dput; 298 } 299 300 /* Establish highest kernel protocol version */ 301 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION) 302 sbi->version = AUTOFS_MAX_PROTO_VERSION; 303 else 304 sbi->version = sbi->max_proto; 305 sbi->sub_version = AUTOFS_PROTO_SUBVERSION; 306 307 if (pgrp_set) { 308 sbi->oz_pgrp = find_get_pid(pgrp); 309 if (!sbi->oz_pgrp) { 310 pr_err("could not find process group %d\n", 311 pgrp); 312 goto fail_dput; 313 } 314 } else { 315 sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID); 316 } 317 318 if (autofs_type_trigger(sbi->type)) 319 __managed_dentry_set_managed(root); 320 321 root_inode->i_fop = &autofs_root_operations; 322 root_inode->i_op = &autofs_dir_inode_operations; 323 324 pr_debug("pipe fd = %d, pgrp = %u\n", 325 sbi->pipefd, pid_nr(sbi->oz_pgrp)); 326 pipe = fget(sbi->pipefd); 327 328 if (!pipe) { 329 pr_err("could not open pipe file descriptor\n"); 330 goto fail_put_pid; 331 } 332 ret = autofs_prepare_pipe(pipe); 333 if (ret < 0) 334 goto fail_fput; 335 sbi->pipe = pipe; 336 sbi->flags &= ~AUTOFS_SBI_CATATONIC; 337 338 /* 339 * Success! Install the root dentry now to indicate completion. 340 */ 341 s->s_root = root; 342 return 0; 343 344 /* 345 * Failure ... clean up. 346 */ 347 fail_fput: 348 pr_err("pipe file descriptor does not contain proper ops\n"); 349 fput(pipe); 350 fail_put_pid: 351 put_pid(sbi->oz_pgrp); 352 fail_dput: 353 dput(root); 354 goto fail_free; 355 fail_ino: 356 autofs_free_ino(ino); 357 fail_free: 358 kfree(sbi); 359 s->s_fs_info = NULL; 360 return ret; 361 } 362 363 struct inode *autofs_get_inode(struct super_block *sb, umode_t mode) 364 { 365 struct inode *inode = new_inode(sb); 366 367 if (inode == NULL) 368 return NULL; 369 370 inode->i_mode = mode; 371 if (sb->s_root) { 372 inode->i_uid = d_inode(sb->s_root)->i_uid; 373 inode->i_gid = d_inode(sb->s_root)->i_gid; 374 } 375 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); 376 inode->i_ino = get_next_ino(); 377 378 if (S_ISDIR(mode)) { 379 set_nlink(inode, 2); 380 inode->i_op = &autofs_dir_inode_operations; 381 inode->i_fop = &autofs_dir_operations; 382 } else if (S_ISLNK(mode)) { 383 inode->i_op = &autofs_symlink_inode_operations; 384 } else 385 WARN_ON(1); 386 387 return inode; 388 } 389