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        int compat_daemon;
 114        unsigned long exp_timeout;
 115        unsigned int type;
 116        int reghost_enabled;
 117        int needs_reghost;
 118        struct super_block *sb;
 119        struct mutex wq_mutex;
 120        struct mutex pipe_mutex;
 121        spinlock_t fs_lock;
 122        struct autofs_wait_queue *queues; /* Wait queue pointer */
 123        spinlock_t lookup_lock;
 124        struct list_head active_list;
 125        struct list_head expiring_list;
 126};
 127
 128static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 129{
 130        return (struct autofs_sb_info *)(sb->s_fs_info);
 131}
 132
 133static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 134{
 135        return (struct autofs_info *)(dentry->d_fsdata);
 136}
 137
 138/* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 139   processes which do manipulations for us in user space sees the raw
 140   filesystem without "magic".) */
 141
 142static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 143        return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 144}
 145
 146/* Does a dentry have some pending activity? */
 147static inline int autofs4_ispending(struct dentry *dentry)
 148{
 149        struct autofs_info *inf = autofs4_dentry_ino(dentry);
 150
 151        if (inf->flags & AUTOFS_INF_PENDING)
 152                return 1;
 153
 154        if (inf->flags & AUTOFS_INF_EXPIRING)
 155                return 1;
 156
 157        return 0;
 158}
 159
 160struct inode *autofs4_get_inode(struct super_block *, umode_t);
 161void autofs4_free_ino(struct autofs_info *);
 162
 163/* Expiration */
 164int is_autofs4_dentry(struct dentry *);
 165int autofs4_expire_wait(struct dentry *dentry);
 166int autofs4_expire_run(struct super_block *, struct vfsmount *,
 167                        struct autofs_sb_info *,
 168                        struct autofs_packet_expire __user *);
 169int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 170                            struct autofs_sb_info *sbi, int when);
 171int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 172                        struct autofs_sb_info *, int __user *);
 173struct dentry *autofs4_expire_direct(struct super_block *sb,
 174                                     struct vfsmount *mnt,
 175                                     struct autofs_sb_info *sbi, int how);
 176struct dentry *autofs4_expire_indirect(struct super_block *sb,
 177                                       struct vfsmount *mnt,
 178                                       struct autofs_sb_info *sbi, int how);
 179
 180/* Device node initialization */
 181
 182int autofs_dev_ioctl_init(void);
 183void autofs_dev_ioctl_exit(void);
 184
 185/* Operations structures */
 186
 187extern const struct inode_operations autofs4_symlink_inode_operations;
 188extern const struct inode_operations autofs4_dir_inode_operations;
 189extern const struct file_operations autofs4_dir_operations;
 190extern const struct file_operations autofs4_root_operations;
 191extern const struct dentry_operations autofs4_dentry_operations;
 192
 193/* VFS automount flags management functions */
 194
 195static inline void __managed_dentry_set_automount(struct dentry *dentry)
 196{
 197        dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 198}
 199
 200static inline void managed_dentry_set_automount(struct dentry *dentry)
 201{
 202        spin_lock(&dentry->d_lock);
 203        __managed_dentry_set_automount(dentry);
 204        spin_unlock(&dentry->d_lock);
 205}
 206
 207static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 208{
 209        dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 210}
 211
 212static inline void managed_dentry_clear_automount(struct dentry *dentry)
 213{
 214        spin_lock(&dentry->d_lock);
 215        __managed_dentry_clear_automount(dentry);
 216        spin_unlock(&dentry->d_lock);
 217}
 218
 219static inline void __managed_dentry_set_transit(struct dentry *dentry)
 220{
 221        dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 222}
 223
 224static inline void managed_dentry_set_transit(struct dentry *dentry)
 225{
 226        spin_lock(&dentry->d_lock);
 227        __managed_dentry_set_transit(dentry);
 228        spin_unlock(&dentry->d_lock);
 229}
 230
 231static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 232{
 233        dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 234}
 235
 236static inline void managed_dentry_clear_transit(struct dentry *dentry)
 237{
 238        spin_lock(&dentry->d_lock);
 239        __managed_dentry_clear_transit(dentry);
 240        spin_unlock(&dentry->d_lock);
 241}
 242
 243static inline void __managed_dentry_set_managed(struct dentry *dentry)
 244{
 245        dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 246}
 247
 248static inline void managed_dentry_set_managed(struct dentry *dentry)
 249{
 250        spin_lock(&dentry->d_lock);
 251        __managed_dentry_set_managed(dentry);
 252        spin_unlock(&dentry->d_lock);
 253}
 254
 255static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 256{
 257        dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 258}
 259
 260static inline void managed_dentry_clear_managed(struct dentry *dentry)
 261{
 262        spin_lock(&dentry->d_lock);
 263        __managed_dentry_clear_managed(dentry);
 264        spin_unlock(&dentry->d_lock);
 265}
 266
 267/* Initializing function */
 268
 269int autofs4_fill_super(struct super_block *, void *, int);
 270struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 271void autofs4_clean_ino(struct autofs_info *);
 272
 273/* Queue management functions */
 274
 275int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 276int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 277void autofs4_catatonic_mode(struct autofs_sb_info *);
 278
 279static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 280{
 281        return new_encode_dev(sbi->sb->s_dev);
 282}
 283
 284static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 285{
 286        return sbi->sb->s_root->d_inode->i_ino;
 287}
 288
 289static inline int simple_positive(struct dentry *dentry)
 290{
 291        return dentry->d_inode && !d_unhashed(dentry);
 292}
 293
 294static inline void __autofs4_add_expiring(struct dentry *dentry)
 295{
 296        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 297        struct autofs_info *ino = autofs4_dentry_ino(dentry);
 298        if (ino) {
 299                if (list_empty(&ino->expiring))
 300                        list_add(&ino->expiring, &sbi->expiring_list);
 301        }
 302        return;
 303}
 304
 305static inline void autofs4_add_expiring(struct dentry *dentry)
 306{
 307        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 308        struct autofs_info *ino = autofs4_dentry_ino(dentry);
 309        if (ino) {
 310                spin_lock(&sbi->lookup_lock);
 311                if (list_empty(&ino->expiring))
 312                        list_add(&ino->expiring, &sbi->expiring_list);
 313                spin_unlock(&sbi->lookup_lock);
 314        }
 315        return;
 316}
 317
 318static inline void autofs4_del_expiring(struct dentry *dentry)
 319{
 320        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 321        struct autofs_info *ino = autofs4_dentry_ino(dentry);
 322        if (ino) {
 323                spin_lock(&sbi->lookup_lock);
 324                if (!list_empty(&ino->expiring))
 325                        list_del_init(&ino->expiring);
 326                spin_unlock(&sbi->lookup_lock);
 327        }
 328        return;
 329}
 330
 331extern void autofs4_kill_sb(struct super_block *);
 332