linux/fs/autofs4/inode.c
<<
>>
Prefs
   1/* -*- c -*- --------------------------------------------------------------- *
   2 *
   3 * linux/fs/autofs/inode.c
   4 *
   5 *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
   6 *  Copyright 2005-2006 Ian Kent <raven@themaw.net>
   7 *
   8 * This file is part of the Linux kernel and is made available under
   9 * the terms of the GNU General Public License, version 2, or at your
  10 * option, any later version, incorporated herein by reference.
  11 *
  12 * ------------------------------------------------------------------------- */
  13
  14#include <linux/kernel.h>
  15#include <linux/slab.h>
  16#include <linux/file.h>
  17#include <linux/seq_file.h>
  18#include <linux/pagemap.h>
  19#include <linux/parser.h>
  20#include <linux/bitops.h>
  21#include <linux/magic.h>
  22#include "autofs_i.h"
  23#include <linux/module.h>
  24
  25struct autofs_info *autofs4_new_ino(struct autofs_sb_info *sbi)
  26{
  27        struct autofs_info *ino = kzalloc(sizeof(*ino), GFP_KERNEL);
  28        if (ino) {
  29                INIT_LIST_HEAD(&ino->active);
  30                INIT_LIST_HEAD(&ino->expiring);
  31                ino->last_used = jiffies;
  32                ino->sbi = sbi;
  33        }
  34        return ino;
  35}
  36
  37void autofs4_clean_ino(struct autofs_info *ino)
  38{
  39        ino->uid = 0;
  40        ino->gid = 0;
  41        ino->last_used = jiffies;
  42}
  43
  44void autofs4_free_ino(struct autofs_info *ino)
  45{
  46        kfree(ino);
  47}
  48
  49void autofs4_kill_sb(struct super_block *sb)
  50{
  51        struct autofs_sb_info *sbi = autofs4_sbi(sb);
  52
  53        /*
  54         * In the event of a failure in get_sb_nodev the superblock
  55         * info is not present so nothing else has been setup, so
  56         * just call kill_anon_super when we are called from
  57         * deactivate_super.
  58         */
  59        if (!sbi)
  60                goto out_kill_sb;
  61
  62        /* Free wait queues, close pipe */
  63        autofs4_catatonic_mode(sbi);
  64
  65        sb->s_fs_info = NULL;
  66        kfree(sbi);
  67
  68out_kill_sb:
  69        DPRINTK("shutting down");
  70        kill_litter_super(sb);
  71}
  72
  73static int autofs4_show_options(struct seq_file *m, struct dentry *root)
  74{
  75        struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
  76        struct inode *root_inode = root->d_sb->s_root->d_inode;
  77
  78        if (!sbi)
  79                return 0;
  80
  81        seq_printf(m, ",fd=%d", sbi->pipefd);
  82        if (root_inode->i_uid != 0)
  83                seq_printf(m, ",uid=%u", root_inode->i_uid);
  84        if (root_inode->i_gid != 0)
  85                seq_printf(m, ",gid=%u", root_inode->i_gid);
  86        seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
  87        seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
  88        seq_printf(m, ",minproto=%d", sbi->min_proto);
  89        seq_printf(m, ",maxproto=%d", sbi->max_proto);
  90
  91        if (autofs_type_offset(sbi->type))
  92                seq_printf(m, ",offset");
  93        else if (autofs_type_direct(sbi->type))
  94                seq_printf(m, ",direct");
  95        else
  96                seq_printf(m, ",indirect");
  97
  98        return 0;
  99}
 100
 101static void autofs4_evict_inode(struct inode *inode)
 102{
 103        clear_inode(inode);
 104        kfree(inode->i_private);
 105}
 106
 107static const struct super_operations autofs4_sops = {
 108        .statfs         = simple_statfs,
 109        .show_options   = autofs4_show_options,
 110        .evict_inode    = autofs4_evict_inode,
 111};
 112
 113enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
 114        Opt_indirect, Opt_direct, Opt_offset};
 115
 116static 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_err, NULL}
 127};
 128
 129static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
 130                pid_t *pgrp, unsigned int *type, 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        *pgrp = task_pgrp_nr(current);
 139
 140        *minproto = AUTOFS_MIN_PROTO_VERSION;
 141        *maxproto = AUTOFS_MAX_PROTO_VERSION;
 142
 143        *pipefd = -1;
 144
 145        if (!options)
 146                return 1;
 147
 148        while ((p = strsep(&options, ",")) != NULL) {
 149                int token;
 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 = option;
 163                        break;
 164                case Opt_gid:
 165                        if (match_int(args, &option))
 166                                return 1;
 167                        *gid = option;
 168                        break;
 169                case Opt_pgrp:
 170                        if (match_int(args, &option))
 171                                return 1;
 172                        *pgrp = option;
 173                        break;
 174                case Opt_minproto:
 175                        if (match_int(args, &option))
 176                                return 1;
 177                        *minproto = option;
 178                        break;
 179                case Opt_maxproto:
 180                        if (match_int(args, &option))
 181                                return 1;
 182                        *maxproto = option;
 183                        break;
 184                case Opt_indirect:
 185                        set_autofs_type_indirect(type);
 186                        break;
 187                case Opt_direct:
 188                        set_autofs_type_direct(type);
 189                        break;
 190                case Opt_offset:
 191                        set_autofs_type_offset(type);
 192                        break;
 193                default:
 194                        return 1;
 195                }
 196        }
 197        return (*pipefd < 0);
 198}
 199
 200int autofs4_fill_super(struct super_block *s, void *data, int silent)
 201{
 202        struct inode * root_inode;
 203        struct dentry * root;
 204        struct file * pipe;
 205        int pipefd;
 206        struct autofs_sb_info *sbi;
 207        struct autofs_info *ino;
 208
 209        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 210        if (!sbi)
 211                goto fail_unlock;
 212        DPRINTK("starting up, sbi = %p",sbi);
 213
 214        s->s_fs_info = sbi;
 215        sbi->magic = AUTOFS_SBI_MAGIC;
 216        sbi->pipefd = -1;
 217        sbi->pipe = NULL;
 218        sbi->catatonic = 1;
 219        sbi->exp_timeout = 0;
 220        sbi->oz_pgrp = task_pgrp_nr(current);
 221        sbi->sb = s;
 222        sbi->version = 0;
 223        sbi->sub_version = 0;
 224        set_autofs_type_indirect(&sbi->type);
 225        sbi->min_proto = 0;
 226        sbi->max_proto = 0;
 227        mutex_init(&sbi->wq_mutex);
 228        mutex_init(&sbi->pipe_mutex);
 229        spin_lock_init(&sbi->fs_lock);
 230        sbi->queues = NULL;
 231        spin_lock_init(&sbi->lookup_lock);
 232        INIT_LIST_HEAD(&sbi->active_list);
 233        INIT_LIST_HEAD(&sbi->expiring_list);
 234        s->s_blocksize = 1024;
 235        s->s_blocksize_bits = 10;
 236        s->s_magic = AUTOFS_SUPER_MAGIC;
 237        s->s_op = &autofs4_sops;
 238        s->s_d_op = &autofs4_dentry_operations;
 239        s->s_time_gran = 1;
 240
 241        /*
 242         * Get the root inode and dentry, but defer checking for errors.
 243         */
 244        ino = autofs4_new_ino(sbi);
 245        if (!ino)
 246                goto fail_free;
 247        root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
 248        root = d_make_root(root_inode);
 249        if (!root)
 250                goto fail_ino;
 251        pipe = NULL;
 252
 253        root->d_fsdata = ino;
 254
 255        /* Can this call block? */
 256        if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
 257                                &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
 258                                &sbi->max_proto)) {
 259                printk("autofs: called with bogus options\n");
 260                goto fail_dput;
 261        }
 262
 263        if (autofs_type_trigger(sbi->type))
 264                __managed_dentry_set_managed(root);
 265
 266        root_inode->i_fop = &autofs4_root_operations;
 267        root_inode->i_op = &autofs4_dir_inode_operations;
 268
 269        /* Couldn't this be tested earlier? */
 270        if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
 271            sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
 272                printk("autofs: kernel does not match daemon version "
 273                       "daemon (%d, %d) kernel (%d, %d)\n",
 274                        sbi->min_proto, sbi->max_proto,
 275                        AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
 276                goto fail_dput;
 277        }
 278
 279        /* Establish highest kernel protocol version */
 280        if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
 281                sbi->version = AUTOFS_MAX_PROTO_VERSION;
 282        else
 283                sbi->version = sbi->max_proto;
 284        sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
 285
 286        DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
 287        pipe = fget(pipefd);
 288        
 289        if (!pipe) {
 290                printk("autofs: could not open pipe file descriptor\n");
 291                goto fail_dput;
 292        }
 293        if (autofs_prepare_pipe(pipe) < 0)
 294                goto fail_fput;
 295        sbi->pipe = pipe;
 296        sbi->pipefd = pipefd;
 297        sbi->catatonic = 0;
 298
 299        /*
 300         * Success! Install the root dentry now to indicate completion.
 301         */
 302        s->s_root = root;
 303        return 0;
 304        
 305        /*
 306         * Failure ... clean up.
 307         */
 308fail_fput:
 309        printk("autofs: pipe file descriptor does not contain proper ops\n");
 310        fput(pipe);
 311        /* fall through */
 312fail_dput:
 313        dput(root);
 314        goto fail_free;
 315fail_ino:
 316        kfree(ino);
 317fail_free:
 318        kfree(sbi);
 319        s->s_fs_info = NULL;
 320fail_unlock:
 321        return -EINVAL;
 322}
 323
 324struct inode *autofs4_get_inode(struct super_block *sb, umode_t mode)
 325{
 326        struct inode *inode = new_inode(sb);
 327
 328        if (inode == NULL)
 329                return NULL;
 330
 331        inode->i_mode = mode;
 332        if (sb->s_root) {
 333                inode->i_uid = sb->s_root->d_inode->i_uid;
 334                inode->i_gid = sb->s_root->d_inode->i_gid;
 335        }
 336        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 337        inode->i_ino = get_next_ino();
 338
 339        if (S_ISDIR(mode)) {
 340                set_nlink(inode, 2);
 341                inode->i_op = &autofs4_dir_inode_operations;
 342                inode->i_fop = &autofs4_dir_operations;
 343        } else if (S_ISLNK(mode)) {
 344                inode->i_op = &autofs4_symlink_inode_operations;
 345        }
 346
 347        return inode;
 348}
 349
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.