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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved4 * Copyright 2005-2006 Ian Kent <raven@themaw.net>5 */6 7#include <linux/seq_file.h>8#include <linux/pagemap.h>9 10#include "autofs_i.h"11 12struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi)13{14 struct autofs_info *ino;15 16 ino = kzalloc(sizeof(*ino), GFP_KERNEL);17 if (ino) {18 INIT_LIST_HEAD(&ino->active);19 INIT_LIST_HEAD(&ino->expiring);20 ino->last_used = jiffies;21 ino->sbi = sbi;22 ino->exp_timeout = -1;23 ino->count = 1;24 }25 return ino;26}27 28void autofs_clean_ino(struct autofs_info *ino)29{30 ino->uid = GLOBAL_ROOT_UID;31 ino->gid = GLOBAL_ROOT_GID;32 ino->exp_timeout = -1;33 ino->last_used = jiffies;34}35 36void autofs_free_ino(struct autofs_info *ino)37{38 kfree_rcu(ino, rcu);39}40 41void autofs_kill_sb(struct super_block *sb)42{43 struct autofs_sb_info *sbi = autofs_sbi(sb);44 45 /*46 * In the event of a failure in get_sb_nodev the superblock47 * info is not present so nothing else has been setup, so48 * just call kill_anon_super when we are called from49 * deactivate_super.50 */51 if (sbi) {52 /* Free wait queues, close pipe */53 autofs_catatonic_mode(sbi);54 put_pid(sbi->oz_pgrp);55 }56 57 pr_debug("shutting down\n");58 kill_litter_super(sb);59 if (sbi)60 kfree_rcu(sbi, rcu);61}62 63static int autofs_show_options(struct seq_file *m, struct dentry *root)64{65 struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);66 struct inode *root_inode = d_inode(root->d_sb->s_root);67 68 if (!sbi)69 return 0;70 71 seq_printf(m, ",fd=%d", sbi->pipefd);72 if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))73 seq_printf(m, ",uid=%u",74 from_kuid_munged(&init_user_ns, root_inode->i_uid));75 if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))76 seq_printf(m, ",gid=%u",77 from_kgid_munged(&init_user_ns, root_inode->i_gid));78 seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp));79 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);80 seq_printf(m, ",minproto=%d", sbi->min_proto);81 seq_printf(m, ",maxproto=%d", sbi->max_proto);82 83 if (autofs_type_offset(sbi->type))84 seq_puts(m, ",offset");85 else if (autofs_type_direct(sbi->type))86 seq_puts(m, ",direct");87 else88 seq_puts(m, ",indirect");89 if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE)90 seq_puts(m, ",strictexpire");91 if (sbi->flags & AUTOFS_SBI_IGNORE)92 seq_puts(m, ",ignore");93#ifdef CONFIG_CHECKPOINT_RESTORE94 if (sbi->pipe)95 seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);96 else97 seq_puts(m, ",pipe_ino=-1");98#endif99 return 0;100}101 102static void autofs_evict_inode(struct inode *inode)103{104 clear_inode(inode);105 kfree(inode->i_private);106}107 108static const struct super_operations autofs_sops = {109 .statfs = simple_statfs,110 .show_options = autofs_show_options,111 .evict_inode = autofs_evict_inode,112};113 114enum {115 Opt_direct,116 Opt_fd,117 Opt_gid,118 Opt_ignore,119 Opt_indirect,120 Opt_maxproto,121 Opt_minproto,122 Opt_offset,123 Opt_pgrp,124 Opt_strictexpire,125 Opt_uid,126};127 128const struct fs_parameter_spec autofs_param_specs[] = {129 fsparam_flag ("direct", Opt_direct),130 fsparam_fd ("fd", Opt_fd),131 fsparam_gid ("gid", Opt_gid),132 fsparam_flag ("ignore", Opt_ignore),133 fsparam_flag ("indirect", Opt_indirect),134 fsparam_u32 ("maxproto", Opt_maxproto),135 fsparam_u32 ("minproto", Opt_minproto),136 fsparam_flag ("offset", Opt_offset),137 fsparam_u32 ("pgrp", Opt_pgrp),138 fsparam_flag ("strictexpire", Opt_strictexpire),139 fsparam_uid ("uid", Opt_uid),140 {}141};142 143struct autofs_fs_context {144 kuid_t uid;145 kgid_t gid;146 int pgrp;147 bool pgrp_set;148};149 150/*151 * Open the fd. We do it here rather than in get_tree so that it's done in the152 * context of the system call that passed the data and not the one that153 * triggered the superblock creation, lest the fd gets reassigned.154 */155static int autofs_parse_fd(struct fs_context *fc, struct autofs_sb_info *sbi,156 struct fs_parameter *param,157 struct fs_parse_result *result)158{159 struct file *pipe;160 int ret;161 162 if (param->type == fs_value_is_file) {163 /* came through the new api */164 pipe = param->file;165 param->file = NULL;166 } else {167 pipe = fget(result->uint_32);168 }169 if (!pipe) {170 errorf(fc, "could not open pipe file descriptor");171 return -EBADF;172 }173 174 ret = autofs_check_pipe(pipe);175 if (ret < 0) {176 errorf(fc, "Invalid/unusable pipe");177 fput(pipe);178 return -EBADF;179 }180 181 autofs_set_packet_pipe_flags(pipe);182 183 if (sbi->pipe)184 fput(sbi->pipe);185 186 sbi->pipefd = result->uint_32;187 sbi->pipe = pipe;188 189 return 0;190}191 192static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param)193{194 struct autofs_fs_context *ctx = fc->fs_private;195 struct autofs_sb_info *sbi = fc->s_fs_info;196 struct fs_parse_result result;197 int opt;198 199 opt = fs_parse(fc, autofs_param_specs, param, &result);200 if (opt < 0)201 return opt;202 203 switch (opt) {204 case Opt_fd:205 return autofs_parse_fd(fc, sbi, param, &result);206 case Opt_uid:207 ctx->uid = result.uid;208 break;209 case Opt_gid:210 ctx->gid = result.gid;211 break;212 case Opt_pgrp:213 ctx->pgrp = result.uint_32;214 ctx->pgrp_set = true;215 break;216 case Opt_minproto:217 sbi->min_proto = result.uint_32;218 break;219 case Opt_maxproto:220 sbi->max_proto = result.uint_32;221 break;222 case Opt_indirect:223 set_autofs_type_indirect(&sbi->type);224 break;225 case Opt_direct:226 set_autofs_type_direct(&sbi->type);227 break;228 case Opt_offset:229 set_autofs_type_offset(&sbi->type);230 break;231 case Opt_strictexpire:232 sbi->flags |= AUTOFS_SBI_STRICTEXPIRE;233 break;234 case Opt_ignore:235 sbi->flags |= AUTOFS_SBI_IGNORE;236 }237 238 return 0;239}240 241static struct autofs_sb_info *autofs_alloc_sbi(void)242{243 struct autofs_sb_info *sbi;244 245 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);246 if (!sbi)247 return NULL;248 249 sbi->magic = AUTOFS_SBI_MAGIC;250 sbi->flags = AUTOFS_SBI_CATATONIC;251 sbi->min_proto = AUTOFS_MIN_PROTO_VERSION;252 sbi->max_proto = AUTOFS_MAX_PROTO_VERSION;253 sbi->pipefd = -1;254 255 set_autofs_type_indirect(&sbi->type);256 mutex_init(&sbi->wq_mutex);257 mutex_init(&sbi->pipe_mutex);258 spin_lock_init(&sbi->fs_lock);259 spin_lock_init(&sbi->lookup_lock);260 INIT_LIST_HEAD(&sbi->active_list);261 INIT_LIST_HEAD(&sbi->expiring_list);262 263 return sbi;264}265 266static int autofs_validate_protocol(struct fs_context *fc)267{268 struct autofs_sb_info *sbi = fc->s_fs_info;269 270 /* Test versions first */271 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||272 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {273 errorf(fc, "kernel does not match daemon version "274 "daemon (%d, %d) kernel (%d, %d)\n",275 sbi->min_proto, sbi->max_proto,276 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);277 return -EINVAL;278 }279 280 /* Establish highest kernel protocol version */281 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)282 sbi->version = AUTOFS_MAX_PROTO_VERSION;283 else284 sbi->version = sbi->max_proto;285 286 switch (sbi->version) {287 case 4:288 sbi->sub_version = 7;289 break;290 case 5:291 sbi->sub_version = AUTOFS_PROTO_SUBVERSION;292 break;293 default:294 sbi->sub_version = 0;295 }296 297 return 0;298}299 300static int autofs_fill_super(struct super_block *s, struct fs_context *fc)301{302 struct autofs_fs_context *ctx = fc->fs_private;303 struct autofs_sb_info *sbi = s->s_fs_info;304 struct inode *root_inode;305 struct autofs_info *ino;306 307 pr_debug("starting up, sbi = %p\n", sbi);308 309 sbi->sb = s;310 s->s_blocksize = 1024;311 s->s_blocksize_bits = 10;312 s->s_magic = AUTOFS_SUPER_MAGIC;313 s->s_op = &autofs_sops;314 s->s_d_op = &autofs_dentry_operations;315 s->s_time_gran = 1;316 317 /*318 * Get the root inode and dentry, but defer checking for errors.319 */320 ino = autofs_new_ino(sbi);321 if (!ino)322 return -ENOMEM;323 324 root_inode = autofs_get_inode(s, S_IFDIR | 0755);325 if (!root_inode)326 return -ENOMEM;327 328 root_inode->i_uid = ctx->uid;329 root_inode->i_gid = ctx->gid;330 root_inode->i_fop = &autofs_root_operations;331 root_inode->i_op = &autofs_dir_inode_operations;332 333 s->s_root = d_make_root(root_inode);334 if (unlikely(!s->s_root)) {335 autofs_free_ino(ino);336 return -ENOMEM;337 }338 s->s_root->d_fsdata = ino;339 340 if (ctx->pgrp_set) {341 sbi->oz_pgrp = find_get_pid(ctx->pgrp);342 if (!sbi->oz_pgrp)343 return invalf(fc, "Could not find process group %d",344 ctx->pgrp);345 } else346 sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);347 348 if (autofs_type_trigger(sbi->type))349 /* s->s_root won't be contended so there's little to350 * be gained by not taking the d_lock when setting351 * d_flags, even when a lot mounts are being done.352 */353 managed_dentry_set_managed(s->s_root);354 355 pr_debug("pipe fd = %d, pgrp = %u\n",356 sbi->pipefd, pid_nr(sbi->oz_pgrp));357 358 sbi->flags &= ~AUTOFS_SBI_CATATONIC;359 return 0;360}361 362/*363 * Validate the parameters and then request a superblock.364 */365static int autofs_get_tree(struct fs_context *fc)366{367 struct autofs_sb_info *sbi = fc->s_fs_info;368 int ret;369 370 ret = autofs_validate_protocol(fc);371 if (ret)372 return ret;373 374 if (sbi->pipefd < 0)375 return invalf(fc, "No control pipe specified");376 377 return get_tree_nodev(fc, autofs_fill_super);378}379 380static void autofs_free_fc(struct fs_context *fc)381{382 struct autofs_fs_context *ctx = fc->fs_private;383 struct autofs_sb_info *sbi = fc->s_fs_info;384 385 if (sbi) {386 if (sbi->pipe)387 fput(sbi->pipe);388 kfree(sbi);389 }390 kfree(ctx);391}392 393static const struct fs_context_operations autofs_context_ops = {394 .free = autofs_free_fc,395 .parse_param = autofs_parse_param,396 .get_tree = autofs_get_tree,397};398 399/*400 * Set up the filesystem mount context.401 */402int autofs_init_fs_context(struct fs_context *fc)403{404 struct autofs_fs_context *ctx;405 struct autofs_sb_info *sbi;406 407 ctx = kzalloc(sizeof(struct autofs_fs_context), GFP_KERNEL);408 if (!ctx)409 goto nomem;410 411 ctx->uid = current_uid();412 ctx->gid = current_gid();413 414 sbi = autofs_alloc_sbi();415 if (!sbi)416 goto nomem_ctx;417 418 fc->fs_private = ctx;419 fc->s_fs_info = sbi;420 fc->ops = &autofs_context_ops;421 return 0;422 423nomem_ctx:424 kfree(ctx);425nomem:426 return -ENOMEM;427}428 429struct inode *autofs_get_inode(struct super_block *sb, umode_t mode)430{431 struct inode *inode = new_inode(sb);432 433 if (inode == NULL)434 return NULL;435 436 inode->i_mode = mode;437 if (sb->s_root) {438 inode->i_uid = d_inode(sb->s_root)->i_uid;439 inode->i_gid = d_inode(sb->s_root)->i_gid;440 }441 simple_inode_init_ts(inode);442 inode->i_ino = get_next_ino();443 444 if (S_ISDIR(mode)) {445 set_nlink(inode, 2);446 inode->i_op = &autofs_dir_inode_operations;447 inode->i_fop = &autofs_dir_operations;448 } else if (S_ISLNK(mode)) {449 inode->i_op = &autofs_symlink_inode_operations;450 } else451 WARN_ON(1);452 453 return inode;454}455