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#ifdef DEBUG
  43#define DPRINTK(fmt, args...)                           \
  44do {                                                    \
  45        printk(KERN_DEBUG "pid %d: %s: " fmt "\n",      \
  46                current->pid, __func__, ##args);        \
  47} while (0)
  48#else
  49#define DPRINTK(fmt, args...) do {} while (0)
  50#endif
  51
  52#define AUTOFS_WARN(fmt, args...)                       \
  53do {                                                    \
  54        printk(KERN_WARNING "pid %d: %s: " fmt "\n",    \
  55                current->pid, __func__, ##args);        \
  56} while (0)
  57
  58#define AUTOFS_ERROR(fmt, args...)                      \
  59do {                                                    \
  60        printk(KERN_ERR "pid %d: %s: " fmt "\n",        \
  61                current->pid, __func__, ##args);        \
  62} while (0)
  63
  64extern spinlock_t autofs4_lock;
  65
  66/* Unified info structure.  This is pointed to by both the dentry and
  67   inode structures.  Each file in the filesystem has an instance of this
  68   structure.  It holds a reference to the dentry, so dentries are never
  69   flushed while the file exists.  All name lookups are dealt with at the
  70   dentry level, although the filesystem can interfere in the validation
  71   process.  Readdir is implemented by traversing the dentry lists. */
  72struct autofs_info {
  73        struct dentry   *dentry;
  74        struct inode    *inode;
  75
  76        int             flags;
  77
  78        struct completion expire_complete;
  79
  80        struct list_head active;
  81        int active_count;
  82
  83        struct list_head expiring;
  84
  85        struct autofs_sb_info *sbi;
  86        unsigned long last_used;
  87        atomic_t count;
  88
  89        uid_t uid;
  90        gid_t gid;
  91};
  92
  93#define AUTOFS_INF_EXPIRING     (1<<0) /* dentry is in the process of expiring */
  94#define AUTOFS_INF_PENDING      (1<<2) /* dentry pending mount */
  95
  96struct autofs_wait_queue {
  97        wait_queue_head_t queue;
  98        struct autofs_wait_queue *next;
  99        autofs_wqt_t wait_queue_token;
 100        /* We use the following to see what we are waiting for */
 101        struct qstr name;
 102        u32 dev;
 103        u64 ino;
 104        uid_t uid;
 105        gid_t gid;
 106        pid_t pid;
 107        pid_t tgid;
 108        /* This is for status reporting upon return */
 109        int status;
 110        unsigned int wait_ctr;
 111};
 112
 113#define AUTOFS_SBI_MAGIC 0x6d4a556d
 114
 115struct autofs_sb_info {
 116        u32 magic;
 117        int pipefd;
 118        struct file *pipe;
 119        pid_t oz_pgrp;
 120        int catatonic;
 121        int version;
 122        int sub_version;
 123        int min_proto;
 124        int max_proto;
 125        unsigned long exp_timeout;
 126        unsigned int type;
 127        int reghost_enabled;
 128        int needs_reghost;
 129        struct super_block *sb;
 130        struct mutex wq_mutex;
 131        spinlock_t fs_lock;
 132        struct autofs_wait_queue *queues; /* Wait queue pointer */
 133        spinlock_t lookup_lock;
 134        struct list_head active_list;
 135        struct list_head expiring_list;
 136};
 137
 138static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 139{
 140        return (struct autofs_sb_info *)(sb->s_fs_info);
 141}
 142
 143static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 144{
 145        return (struct autofs_info *)(dentry->d_fsdata);
 146}
 147
 148/* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 149   processes which do manipulations for us in user space sees the raw
 150   filesystem without "magic".) */
 151
 152static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 153        return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 154}
 155
 156/* Does a dentry have some pending activity? */
 157static inline int autofs4_ispending(struct dentry *dentry)
 158{
 159        struct autofs_info *inf = autofs4_dentry_ino(dentry);
 160
 161        if (inf->flags & AUTOFS_INF_PENDING)
 162                return 1;
 163
 164        if (inf->flags & AUTOFS_INF_EXPIRING)
 165                return 1;
 166
 167        return 0;
 168}
 169
 170struct inode *autofs4_get_inode(struct super_block *, mode_t);
 171void autofs4_free_ino(struct autofs_info *);
 172
 173/* Expiration */
 174int is_autofs4_dentry(struct dentry *);
 175int autofs4_expire_wait(struct dentry *dentry);
 176int autofs4_expire_run(struct super_block *, struct vfsmount *,
 177                        struct autofs_sb_info *,
 178                        struct autofs_packet_expire __user *);
 179int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 180                            struct autofs_sb_info *sbi, int when);
 181int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 182                        struct autofs_sb_info *, int __user *);
 183struct dentry *autofs4_expire_direct(struct super_block *sb,
 184                                     struct vfsmount *mnt,
 185                                     struct autofs_sb_info *sbi, int how);
 186struct dentry *autofs4_expire_indirect(struct super_block *sb,
 187                                       struct vfsmount *mnt,
 188                                       struct autofs_sb_info *sbi, int how);
 189
 190/* Device node initialization */
 191
 192int autofs_dev_ioctl_init(void);
 193void autofs_dev_ioctl_exit(void);
 194
 195/* Operations structures */
 196
 197extern const struct inode_operations autofs4_symlink_inode_operations;
 198extern const struct inode_operations autofs4_dir_inode_operations;
 199extern const struct file_operations autofs4_dir_operations;
 200extern const struct file_operations autofs4_root_operations;
 201extern const struct dentry_operations autofs4_dentry_operations;
 202
 203/* VFS automount flags management functions */
 204
 205static inline void __managed_dentry_set_automount(struct dentry *dentry)
 206{
 207        dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 208}
 209
 210static inline void managed_dentry_set_automount(struct dentry *dentry)
 211{
 212        spin_lock(&dentry->d_lock);
 213        __managed_dentry_set_automount(dentry);
 214        spin_unlock(&dentry->d_lock);
 215}
 216
 217static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 218{
 219        dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 220}
 221
 222static inline void managed_dentry_clear_automount(struct dentry *dentry)
 223{
 224        spin_lock(&dentry->d_lock);
 225        __managed_dentry_clear_automount(dentry);
 226        spin_unlock(&dentry->d_lock);
 227}
 228
 229static inline void __managed_dentry_set_transit(struct dentry *dentry)
 230{
 231        dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 232}
 233
 234static inline void managed_dentry_set_transit(struct dentry *dentry)
 235{
 236        spin_lock(&dentry->d_lock);
 237        __managed_dentry_set_transit(dentry);
 238        spin_unlock(&dentry->d_lock);
 239}
 240
 241static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 242{
 243        dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 244}
 245
 246static inline void managed_dentry_clear_transit(struct dentry *dentry)
 247{
 248        spin_lock(&dentry->d_lock);
 249        __managed_dentry_clear_transit(dentry);
 250        spin_unlock(&dentry->d_lock);
 251}
 252
 253static inline void __managed_dentry_set_managed(struct dentry *dentry)
 254{
 255        dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 256}
 257
 258static inline void managed_dentry_set_managed(struct dentry *dentry)
 259{
 260        spin_lock(&dentry->d_lock);
 261        __managed_dentry_set_managed(dentry);
 262        spin_unlock(&dentry->d_lock);
 263}
 264
 265static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 266{
 267        dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 268}
 269
 270static inline void managed_dentry_clear_managed(struct dentry *dentry)
 271{
 272        spin_lock(&dentry->d_lock);
 273        __managed_dentry_clear_managed(dentry);
 274        spin_unlock(&dentry->d_lock);
 275}
 276
 277/* Initializing function */
 278
 279int autofs4_fill_super(struct super_block *, void *, int);
 280struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 281void autofs4_clean_ino(struct autofs_info *);
 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