LXR linux/fs/autofs4/autofs

   1/* -*- c -*- ------------------------------------------------------------- *
   2 *   
   3 * linux/fs/autofs/autofs_i.h
   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/* Internal header file for autofs */
  15
  16#include <linux/auto_fs4.h>
  17#include <linux/auto_dev-ioctl.h>
  18#include <linux/mutex.h>
  19#include <linux/spinlock.h>
  20#include <linux/list.h>
  21
  22/* This is the range of ioctl() numbers we claim as ours */
  23#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
  24#define AUTOFS_IOC_COUNT     32
  25
  26#define AUTOFS_DEV_IOCTL_IOC_FIRST      (AUTOFS_DEV_IOCTL_VERSION)
  27#define AUTOFS_DEV_IOCTL_IOC_COUNT      (AUTOFS_IOC_COUNT - 11)
  28
  29#include <linux/kernel.h>
  30#include <linux/slab.h>
  31#include <linux/time.h>
  32#include <linux/string.h>
  33#include <linux/wait.h>
  34#include <linux/sched.h>
  35#include <linux/mount.h>
  36#include <linux/namei.h>
  37#include <asm/current.h>
  38#include <asm/uaccess.h>
  39
  40/* #define DEBUG */
  41
  42#define DPRINTK(fmt, ...)                               \
  43        pr_debug("pid %d: %s: " fmt "\n",               \
  44                current->pid, __func__, ##__VA_ARGS__)
  45
  46#define AUTOFS_WARN(fmt, ...)                           \
  47        printk(KERN_WARNING "pid %d: %s: " fmt "\n",    \
  48                current->pid, __func__, ##__VA_ARGS__)
  49
  50#define AUTOFS_ERROR(fmt, ...)                          \
  51        printk(KERN_ERR "pid %d: %s: " fmt "\n",        \
  52                current->pid, __func__, ##__VA_ARGS__)
  53
  54/* Unified info structure.  This is pointed to by both the dentry and
  55   inode structures.  Each file in the filesystem has an instance of this
  56   structure.  It holds a reference to the dentry, so dentries are never
  57   flushed while the file exists.  All name lookups are dealt with at the
  58   dentry level, although the filesystem can interfere in the validation
  59   process.  Readdir is implemented by traversing the dentry lists. */
  60struct autofs_info {
  61        struct dentry   *dentry;
  62        struct inode    *inode;
  63
  64        int             flags;
  65
  66        struct completion expire_complete;
  67
  68        struct list_head active;
  69        int active_count;
  70
  71        struct list_head expiring;
  72
  73        struct autofs_sb_info *sbi;
  74        unsigned long last_used;
  75        atomic_t count;
  76
  77        uid_t uid;
  78        gid_t gid;
  79};
  80
  81#define AUTOFS_INF_EXPIRING     (1<<0) /* dentry is in the process of expiring */
  82#define AUTOFS_INF_PENDING      (1<<2) /* dentry pending mount */
  83
  84struct autofs_wait_queue {
  85        wait_queue_head_t queue;
  86        struct autofs_wait_queue *next;
  87        autofs_wqt_t wait_queue_token;
  88        /* We use the following to see what we are waiting for */
  89        struct qstr name;
  90        u32 dev;
  91        u64 ino;
  92        uid_t uid;
  93        gid_t gid;
  94        pid_t pid;
  95        pid_t tgid;
  96        /* This is for status reporting upon return */
  97        int status;
  98        unsigned int wait_ctr;
  99};
 100
 101#define AUTOFS_SBI_MAGIC 0x6d4a556d
 102
 103struct autofs_sb_info {
 104        u32 magic;
 105        int pipefd;
 106        struct file *pipe;
 107        pid_t oz_pgrp;
 108        int catatonic;
 109        int version;
 110        int sub_version;
 111        int min_proto;
 112        int max_proto;
 113        unsigned long exp_timeout;
 114        unsigned int type;
 115        int reghost_enabled;
 116        int needs_reghost;
 117        struct super_block *sb;
 118        struct mutex wq_mutex;
 119        struct mutex pipe_mutex;
 120        spinlock_t fs_lock;
 121        struct autofs_wait_queue *queues; /* Wait queue pointer */
 122        spinlock_t lookup_lock;
 123        struct list_head active_list;
 124        struct list_head expiring_list;
 125};
 126
 127static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 128{
 129        return (struct autofs_sb_info *)(sb->s_fs_info);
 130}
 131
 132static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 133{
 134        return (struct autofs_info *)(dentry->d_fsdata);
 135}
 136
 137/* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 138   processes which do manipulations for us in user space sees the raw
 139   filesystem without "magic".) */
 140
 141static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 142        return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 143}
 144
 145/* Does a dentry have some pending activity? */
 146static inline int autofs4_ispending(struct dentry *dentry)
 147{
 148        struct autofs_info *inf = autofs4_dentry_ino(dentry);
 149
 150        if (inf->flags & AUTOFS_INF_PENDING)
 151                return 1;
 152
 153        if (inf->flags & AUTOFS_INF_EXPIRING)
 154                return 1;
 155
 156        return 0;
 157}
 158
 159struct inode *autofs4_get_inode(struct super_block *, umode_t);
 160void autofs4_free_ino(struct autofs_info *);
 161
 162/* Expiration */
 163int is_autofs4_dentry(struct dentry *);
 164int autofs4_expire_wait(struct dentry *dentry);
 165int autofs4_expire_run(struct super_block *, struct vfsmount *,
 166                        struct autofs_sb_info *,
 167                        struct autofs_packet_expire __user *);
 168int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 169                            struct autofs_sb_info *sbi, int when);
 170int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 171                        struct autofs_sb_info *, int __user *);
 172struct dentry *autofs4_expire_direct(struct super_block *sb,
 173                                     struct vfsmount *mnt,
 174                                     struct autofs_sb_info *sbi, int how);
 175struct dentry *autofs4_expire_indirect(struct super_block *sb,
 176                                       struct vfsmount *mnt,
 177                                       struct autofs_sb_info *sbi, int how);
 178
 179/* Device node initialization */
 180
 181int autofs_dev_ioctl_init(void);
 182void autofs_dev_ioctl_exit(void);
 183
 184/* Operations structures */
 185
 186extern const struct inode_operations autofs4_symlink_inode_operations;
 187extern const struct inode_operations autofs4_dir_inode_operations;
 188extern const struct file_operations autofs4_dir_operations;
 189extern const struct file_operations autofs4_root_operations;
 190extern const struct dentry_operations autofs4_dentry_operations;
 191
 192/* VFS automount flags management functions */
 193
 194static inline void __managed_dentry_set_automount(struct dentry *dentry)
 195{
 196        dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 197}
 198
 199static inline void managed_dentry_set_automount(struct dentry *dentry)
 200{
 201        spin_lock(&dentry->d_lock);
 202        __managed_dentry_set_automount(dentry);
 203        spin_unlock(&dentry->d_lock);
 204}
 205
 206static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 207{
 208        dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 209}
 210
 211static inline void managed_dentry_clear_automount(struct dentry *dentry)
 212{
 213        spin_lock(&dentry->d_lock);
 214        __managed_dentry_clear_automount(dentry);
 215        spin_unlock(&dentry->d_lock);
 216}
 217
 218static inline void __managed_dentry_set_transit(struct dentry *dentry)
 219{
 220        dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 221}
 222
 223static inline void managed_dentry_set_transit(struct dentry *dentry)
 224{
 225        spin_lock(&dentry->d_lock);
 226        __managed_dentry_set_transit(dentry);
 227        spin_unlock(&dentry->d_lock);
 228}
 229
 230static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 231{
 232        dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 233}
 234
 235static inline void managed_dentry_clear_transit(struct dentry *dentry)
 236{
 237        spin_lock(&dentry->d_lock);
 238        __managed_dentry_clear_transit(dentry);
 239        spin_unlock(&dentry->d_lock);
 240}
 241
 242static inline void __managed_dentry_set_managed(struct dentry *dentry)
 243{
 244        dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 245}
 246
 247static inline void managed_dentry_set_managed(struct dentry *dentry)
 248{
 249        spin_lock(&dentry->d_lock);
 250        __managed_dentry_set_managed(dentry);
 251        spin_unlock(&dentry->d_lock);
 252}
 253
 254static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 255{
 256        dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 257}
 258
 259static inline void managed_dentry_clear_managed(struct dentry *dentry)
 260{
 261        spin_lock(&dentry->d_lock);
 262        __managed_dentry_clear_managed(dentry);
 263        spin_unlock(&dentry->d_lock);
 264}
 265
 266/* Initializing function */
 267
 268int autofs4_fill_super(struct super_block *, void *, int);
 269struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 270void autofs4_clean_ino(struct autofs_info *);
 271
 272static inline int autofs_prepare_pipe(struct file *pipe)
 273{
 274        if (!pipe->f_op || !pipe->f_op->write)
 275                return -EINVAL;
 276        if (!S_ISFIFO(pipe->f_dentry->d_inode->i_mode))
 277                return -EINVAL;
 278        /* We want a packet pipe */
 279        pipe->f_flags |= O_DIRECT;
 280        return 0;
 281}
 282
 283/* Queue management functions */
 284
 285int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 286int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 287void autofs4_catatonic_mode(struct autofs_sb_info *);
 288
 289static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 290{
 291        return new_encode_dev(sbi->sb->s_dev);
 292}
 293
 294static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 295{
 296        return sbi->sb->s_root->d_inode->i_ino;
 297}
 298
 299static inline int simple_positive(struct dentry *dentry)
 300{
 301        return dentry->d_inode && !d_unhashed(dentry);
 302}
 303
 304static inline void __autofs4_add_expiring(struct dentry *dentry)
 305{
 306        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 307        struct autofs_info *ino = autofs4_dentry_ino(dentry);
 308        if (ino) {
 309                if (list_empty(&ino->expiring))
 310                        list_add(&ino->expiring, &sbi->expiring_list);
 311        }
 312        return;
 313}
 314
 315static inline void autofs4_add_expiring(struct dentry *dentry)
 316{
 317        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 318        struct autofs_info *ino = autofs4_dentry_ino(dentry);
 319        if (ino) {
 320                spin_lock(&sbi->lookup_lock);
 321                if (list_empty(&ino->expiring))
 322                        list_add(&ino->expiring, &sbi->expiring_list);
 323                spin_unlock(&sbi->lookup_lock);
 324        }
 325        return;
 326}
 327
 328static inline void autofs4_del_expiring(struct dentry *dentry)
 329{
 330        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 331        struct autofs_info *ino = autofs4_dentry_ino(dentry);
 332        if (ino) {
 333                spin_lock(&sbi->lookup_lock);
 334                if (!list_empty(&ino->expiring))
 335                        list_del_init(&ino->expiring);
 336                spin_unlock(&sbi->lookup_lock);
 337        }
 338        return;
 339}
 340
 341extern void autofs4_kill_sb(struct super_block *);
 342