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