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