1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved 4 * Copyright 2005-2006 Ian Kent <raven@themaw.net> 5 */ 6 7 #include <linux/seq_file.h> 8 #include <linux/pagemap.h> 9 #include <linux/parser.h> 10 11 #include "autofs_i.h" 12 13 struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi) 14 { 15 struct autofs_info *ino; 16 17 ino = kzalloc(sizeof(*ino), GFP_KERNEL); 18 if (ino) { 19 INIT_LIST_HEAD(&ino->active); 20 INIT_LIST_HEAD(&ino->expiring); 21 ino->last_used = jiffies; 22 ino->sbi = sbi; 23 } 24 return ino; 25 } 26 27 void autofs_clean_ino(struct autofs_info *ino) 28 { 29 ino->uid = GLOBAL_ROOT_UID; 30 ino->gid = GLOBAL_ROOT_GID; 31 ino->last_used = jiffies; 32 } 33 34 void autofs_free_ino(struct autofs_info *ino) 35 { 36 kfree_rcu(ino, rcu); 37 } 38 39 void autofs_kill_sb(struct super_block *sb) 40 { 41 struct autofs_sb_info *sbi = autofs_sbi(sb); 42 43 /* 44 * In the event of a failure in get_sb_nodev the superblock 45 * info is not present so nothing else has been setup, so 46 * just call kill_anon_super when we are called from 47 * deactivate_super. 48 */ 49 if (sbi) { 50 /* Free wait queues, close pipe */ 51 autofs_catatonic_mode(sbi); 52 put_pid(sbi->oz_pgrp); 53 } 54 55 pr_debug("shutting down\n"); 56 kill_litter_super(sb); 57 if (sbi) 58 kfree_rcu(sbi, rcu); 59 } 60 61 static int autofs_show_options(struct seq_file *m, struct dentry *root) 62 { 63 struct autofs_sb_info *sbi = autofs_sbi(root->d_sb); 64 struct inode *root_inode = d_inode(root->d_sb->s_root); 65 66 if (!sbi) 67 return 0; 68 69 seq_printf(m, ",fd=%d", sbi->pipefd); 70 if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID)) 71 seq_printf(m, ",uid=%u", 72 from_kuid_munged(&init_user_ns, root_inode->i_uid)); 73 if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID)) 74 seq_printf(m, ",gid=%u", 75 from_kgid_munged(&init_user_ns, root_inode->i_gid)); 76 seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp)); 77 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ); 78 seq_printf(m, ",minproto=%d", sbi->min_proto); 79 seq_printf(m, ",maxproto=%d", sbi->max_proto); 80 81 if (autofs_type_offset(sbi->type)) 82 seq_puts(m, ",offset"); 83 else if (autofs_type_direct(sbi->type)) 84 seq_puts(m, ",direct"); 85 else 86 seq_puts(m, ",indirect"); 87 if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE) 88 seq_puts(m, ",strictexpire"); 89 if (sbi->flags & AUTOFS_SBI_IGNORE) 90 seq_puts(m, ",ignore"); 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_puts(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, Opt_strictexpire, 114 Opt_ignore}; 115 116 static const match_table_t tokens = { 117 {Opt_fd, "fd=%u"}, 118 {Opt_uid, "uid=%u"}, 119 {Opt_gid, "gid=%u"}, 120 {Opt_pgrp, "pgrp=%u"}, 121 {Opt_minproto, "minproto=%u"}, 122 {Opt_maxproto, "maxproto=%u"}, 123 {Opt_indirect, "indirect"}, 124 {Opt_direct, "direct"}, 125 {Opt_offset, "offset"}, 126 {Opt_strictexpire, "strictexpire"}, 127 {Opt_ignore, "ignore"}, 128 {Opt_err, NULL} 129 }; 130 131 static int parse_options(char *options, 132 struct inode *root, int *pgrp, bool *pgrp_set, 133 struct autofs_sb_info *sbi) 134 { 135 char *p; 136 substring_t args[MAX_OPT_ARGS]; 137 int option; 138 int pipefd = -1; 139 kuid_t uid; 140 kgid_t gid; 141 142 root->i_uid = current_uid(); 143 root->i_gid = current_gid(); 144 145 sbi->min_proto = AUTOFS_MIN_PROTO_VERSION; 146 sbi->max_proto = AUTOFS_MAX_PROTO_VERSION; 147 148 sbi->pipefd = -1; 149 150 if (!options) 151 return 1; 152 153 while ((p = strsep(&options, ",")) != NULL) { 154 int token; 155 156 if (!*p) 157 continue; 158 159 token = match_token(p, tokens, args); 160 switch (token) { 161 case Opt_fd: 162 if (match_int(args, &pipefd)) 163 return 1; 164 sbi->pipefd = pipefd; 165 break; 166 case Opt_uid: 167 if (match_int(args, &option)) 168 return 1; 169 uid = make_kuid(current_user_ns(), option); 170 if (!uid_valid(uid)) 171 return 1; 172 root->i_uid = uid; 173 break; 174 case Opt_gid: 175 if (match_int(args, &option)) 176 return 1; 177 gid = make_kgid(current_user_ns(), option); 178 if (!gid_valid(gid)) 179 return 1; 180 root->i_gid = gid; 181 break; 182 case Opt_pgrp: 183 if (match_int(args, &option)) 184 return 1; 185 *pgrp = option; 186 *pgrp_set = true; 187 break; 188 case Opt_minproto: 189 if (match_int(args, &option)) 190 return 1; 191 sbi->min_proto = option; 192 break; 193 case Opt_maxproto: 194 if (match_int(args, &option)) 195 return 1; 196 sbi->max_proto = option; 197 break; 198 case Opt_indirect: 199 set_autofs_type_indirect(&sbi->type); 200 break; 201 case Opt_direct: 202 set_autofs_type_direct(&sbi->type); 203 break; 204 case Opt_offset: 205 set_autofs_type_offset(&sbi->type); 206 break; 207 case Opt_strictexpire: 208 sbi->flags |= AUTOFS_SBI_STRICTEXPIRE; 209 break; 210 case Opt_ignore: 211 sbi->flags |= AUTOFS_SBI_IGNORE; 212 break; 213 default: 214 return 1; 215 } 216 } 217 return (sbi->pipefd < 0); 218 } 219 220 int autofs_fill_super(struct super_block *s, void *data, int silent) 221 { 222 struct inode *root_inode; 223 struct dentry *root; 224 struct file *pipe; 225 struct autofs_sb_info *sbi; 226 struct autofs_info *ino; 227 int pgrp = 0; 228 bool pgrp_set = false; 229 int ret = -EINVAL; 230 231 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 232 if (!sbi) 233 return -ENOMEM; 234 pr_debug("starting up, sbi = %p\n", sbi); 235 236 s->s_fs_info = sbi; 237 sbi->magic = AUTOFS_SBI_MAGIC; 238 sbi->pipefd = -1; 239 sbi->pipe = NULL; 240 sbi->exp_timeout = 0; 241 sbi->oz_pgrp = NULL; 242 sbi->sb = s; 243 sbi->version = 0; 244 sbi->sub_version = 0; 245 sbi->flags = AUTOFS_SBI_CATATONIC; 246 set_autofs_type_indirect(&sbi->type); 247 sbi->min_proto = 0; 248 sbi->max_proto = 0; 249 mutex_init(&sbi->wq_mutex); 250 mutex_init(&sbi->pipe_mutex); 251 spin_lock_init(&sbi->fs_lock); 252 sbi->queues = NULL; 253 spin_lock_init(&sbi->lookup_lock); 254 INIT_LIST_HEAD(&sbi->active_list); 255 INIT_LIST_HEAD(&sbi->expiring_list); 256 s->s_blocksize = 1024; 257 s->s_blocksize_bits = 10; 258 s->s_magic = AUTOFS_SUPER_MAGIC; 259 s->s_op = &autofs_sops; 260 s->s_d_op = &autofs_dentry_operations; 261 s->s_time_gran = 1; 262 263 /* 264 * Get the root inode and dentry, but defer checking for errors. 265 */ 266 ino = autofs_new_ino(sbi); 267 if (!ino) { 268 ret = -ENOMEM; 269 goto fail_free; 270 } 271 root_inode = autofs_get_inode(s, S_IFDIR | 0755); 272 root = d_make_root(root_inode); 273 if (!root) { 274 ret = -ENOMEM; 275 goto fail_ino; 276 } 277 pipe = NULL; 278 279 root->d_fsdata = ino; 280 281 /* Can this call block? */ 282 if (parse_options(data, root_inode, &pgrp, &pgrp_set, sbi)) { 283 pr_err("called with bogus options\n"); 284 goto fail_dput; 285 } 286 287 /* Test versions first */ 288 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION || 289 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) { 290 pr_err("kernel does not match daemon version " 291 "daemon (%d, %d) kernel (%d, %d)\n", 292 sbi->min_proto, sbi->max_proto, 293 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); 294 goto fail_dput; 295 } 296 297 /* Establish highest kernel protocol version */ 298 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION) 299 sbi->version = AUTOFS_MAX_PROTO_VERSION; 300 else 301 sbi->version = sbi->max_proto; 302 sbi->sub_version = AUTOFS_PROTO_SUBVERSION; 303 304 if (pgrp_set) { 305 sbi->oz_pgrp = find_get_pid(pgrp); 306 if (!sbi->oz_pgrp) { 307 pr_err("could not find process group %d\n", 308 pgrp); 309 goto fail_dput; 310 } 311 } else { 312 sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID); 313 } 314 315 if (autofs_type_trigger(sbi->type)) 316 __managed_dentry_set_managed(root); 317 318 root_inode->i_fop = &autofs_root_operations; 319 root_inode->i_op = &autofs_dir_inode_operations; 320 321 pr_debug("pipe fd = %d, pgrp = %u\n", 322 sbi->pipefd, pid_nr(sbi->oz_pgrp)); 323 pipe = fget(sbi->pipefd); 324 325 if (!pipe) { 326 pr_err("could not open pipe file descriptor\n"); 327 goto fail_put_pid; 328 } 329 ret = autofs_prepare_pipe(pipe); 330 if (ret < 0) 331 goto fail_fput; 332 sbi->pipe = pipe; 333 sbi->flags &= ~AUTOFS_SBI_CATATONIC; 334 335 /* 336 * Success! Install the root dentry now to indicate completion. 337 */ 338 s->s_root = root; 339 return 0; 340 341 /* 342 * Failure ... clean up. 343 */ 344 fail_fput: 345 pr_err("pipe file descriptor does not contain proper ops\n"); 346 fput(pipe); 347 fail_put_pid: 348 put_pid(sbi->oz_pgrp); 349 fail_dput: 350 dput(root); 351 goto fail_free; 352 fail_ino: 353 autofs_free_ino(ino); 354 fail_free: 355 kfree(sbi); 356 s->s_fs_info = NULL; 357 return ret; 358 } 359 360 struct inode *autofs_get_inode(struct super_block *sb, umode_t mode) 361 { 362 struct inode *inode = new_inode(sb); 363 364 if (inode == NULL) 365 return NULL; 366 367 inode->i_mode = mode; 368 if (sb->s_root) { 369 inode->i_uid = d_inode(sb->s_root)->i_uid; 370 inode->i_gid = d_inode(sb->s_root)->i_gid; 371 } 372 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); 373 inode->i_ino = get_next_ino(); 374 375 if (S_ISDIR(mode)) { 376 set_nlink(inode, 2); 377 inode->i_op = &autofs_dir_inode_operations; 378 inode->i_fop = &autofs_dir_operations; 379 } else if (S_ISLNK(mode)) { 380 inode->i_op = &autofs_symlink_inode_operations; 381 } else 382 WARN_ON(1); 383 384 return inode; 385 } 386