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/list.h>
  20
  21/* This is the range of ioctl() numbers we claim as ours */
  22#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
  23#define AUTOFS_IOC_COUNT     32
  24
  25#define AUTOFS_DEV_IOCTL_IOC_FIRST      (AUTOFS_DEV_IOCTL_VERSION)
  26#define AUTOFS_DEV_IOCTL_IOC_COUNT      (AUTOFS_IOC_COUNT - 11)
  27
  28#include <linux/kernel.h>
  29#include <linux/slab.h>
  30#include <linux/time.h>
  31#include <linux/string.h>
  32#include <linux/wait.h>
  33#include <linux/sched.h>
  34#include <linux/mount.h>
  35#include <linux/namei.h>
  36#include <asm/current.h>
  37#include <asm/uaccess.h>
  38
  39/* #define DEBUG */
  40
  41#ifdef DEBUG
  42#define DPRINTK(fmt, args...)                           \
  43do {                                                    \
  44        printk(KERN_DEBUG "pid %d: %s: " fmt "\n",      \
  45                current->pid, __func__, ##args);        \
  46} while (0)
  47#else
  48#define DPRINTK(fmt, args...) do {} while (0)
  49#endif
  50
  51#define AUTOFS_WARN(fmt, args...)                       \
  52do {                                                    \
  53        printk(KERN_WARNING "pid %d: %s: " fmt "\n",    \
  54                current->pid, __func__, ##args);        \
  55} while (0)
  56
  57#define AUTOFS_ERROR(fmt, args...)                      \
  58do {                                                    \
  59        printk(KERN_ERR "pid %d: %s: " fmt "\n",        \
  60                current->pid, __func__, ##args);        \
  61} while (0)
  62
  63/* Unified info structure.  This is pointed to by both the dentry and
  64   inode structures.  Each file in the filesystem has an instance of this
  65   structure.  It holds a reference to the dentry, so dentries are never
  66   flushed while the file exists.  All name lookups are dealt with at the
  67   dentry level, although the filesystem can interfere in the validation
  68   process.  Readdir is implemented by traversing the dentry lists. */
  69struct autofs_info {
  70        struct dentry   *dentry;
  71        struct inode    *inode;
  72
  73        int             flags;
  74
  75        struct completion expire_complete;
  76
  77        struct list_head active;
  78        struct list_head expiring;
  79
  80        struct autofs_sb_info *sbi;
  81        unsigned long last_used;
  82        atomic_t count;
  83
  84        uid_t uid;
  85        gid_t gid;
  86
  87        mode_t  mode;
  88        size_t  size;
  89
  90        void (*free)(struct autofs_info *);
  91        union {
  92                const char *symlink;
  93        } u;
  94};
  95
  96#define AUTOFS_INF_EXPIRING     (1<<0) /* dentry is in the process of expiring */
  97#define AUTOFS_INF_MOUNTPOINT   (1<<1) /* mountpoint status for direct expire */
  98
  99struct autofs_wait_queue {
 100        wait_queue_head_t queue;
 101        struct autofs_wait_queue *next;
 102        autofs_wqt_t wait_queue_token;
 103        /* We use the following to see what we are waiting for */
 104        struct qstr name;
 105        u32 dev;
 106        u64 ino;
 107        uid_t uid;
 108        gid_t gid;
 109        pid_t pid;
 110        pid_t tgid;
 111        /* This is for status reporting upon return */
 112        int status;
 113        unsigned int wait_ctr;
 114};
 115
 116#define AUTOFS_SBI_MAGIC 0x6d4a556d
 117
 118struct autofs_sb_info {
 119        u32 magic;
 120        int pipefd;
 121        struct file *pipe;
 122        pid_t oz_pgrp;
 123        int catatonic;
 124        int version;
 125        int sub_version;
 126        int min_proto;
 127        int max_proto;
 128        unsigned long exp_timeout;
 129        unsigned int type;
 130        int reghost_enabled;
 131        int needs_reghost;
 132        struct super_block *sb;
 133        struct mutex wq_mutex;
 134        spinlock_t fs_lock;
 135        struct autofs_wait_queue *queues; /* Wait queue pointer */
 136        spinlock_t lookup_lock;
 137        struct list_head active_list;
 138        struct list_head expiring_list;
 139};
 140
 141static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 142{
 143        return (struct autofs_sb_info *)(sb->s_fs_info);
 144}
 145
 146static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 147{
 148        return (struct autofs_info *)(dentry->d_fsdata);
 149}
 150
 151/* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 152   processes which do manipulations for us in user space sees the raw
 153   filesystem without "magic".) */
 154
 155static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 156        return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 157}
 158
 159/* Does a dentry have some pending activity? */
 160static inline int autofs4_ispending(struct dentry *dentry)
 161{
 162        struct autofs_info *inf = autofs4_dentry_ino(dentry);
 163
 164        if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
 165                return 1;
 166
 167        if (inf->flags & AUTOFS_INF_EXPIRING)
 168                return 1;
 169
 170        return 0;
 171}
 172
 173static inline void autofs4_copy_atime(struct file *src, struct file *dst)
 174{
 175        dst->f_path.dentry->d_inode->i_atime =
 176                src->f_path.dentry->d_inode->i_atime;
 177        return;
 178}
 179
 180struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
 181void autofs4_free_ino(struct autofs_info *);
 182
 183/* Expiration */
 184int is_autofs4_dentry(struct dentry *);
 185int autofs4_expire_wait(struct dentry *dentry);
 186int autofs4_expire_run(struct super_block *, struct vfsmount *,
 187                        struct autofs_sb_info *,
 188                        struct autofs_packet_expire __user *);
 189int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 190                            struct autofs_sb_info *sbi, int when);
 191int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 192                        struct autofs_sb_info *, int __user *);
 193struct dentry *autofs4_expire_direct(struct super_block *sb,
 194                                     struct vfsmount *mnt,
 195                                     struct autofs_sb_info *sbi, int how);
 196struct dentry *autofs4_expire_indirect(struct super_block *sb,
 197                                       struct vfsmount *mnt,
 198                                       struct autofs_sb_info *sbi, int how);
 199
 200/* Device node initialization */
 201
 202int autofs_dev_ioctl_init(void);
 203void autofs_dev_ioctl_exit(void);
 204
 205/* Operations structures */
 206
 207extern const struct inode_operations autofs4_symlink_inode_operations;
 208extern const struct inode_operations autofs4_dir_inode_operations;
 209extern const struct inode_operations autofs4_root_inode_operations;
 210extern const struct inode_operations autofs4_indirect_root_inode_operations;
 211extern const struct inode_operations autofs4_direct_root_inode_operations;
 212extern const struct file_operations autofs4_dir_operations;
 213extern const struct file_operations autofs4_root_operations;
 214
 215/* Initializing function */
 216
 217int autofs4_fill_super(struct super_block *, void *, int);
 218struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
 219
 220/* Queue management functions */
 221
 222int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 223int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 224void autofs4_catatonic_mode(struct autofs_sb_info *);
 225
 226static inline int autofs4_follow_mount(struct path *path)
 227{
 228        int res = 0;
 229
 230        while (d_mountpoint(path->dentry)) {
 231                int followed = follow_down(path);
 232                if (!followed)
 233                        break;
 234                res = 1;
 235        }
 236        return res;
 237}
 238
 239static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 240{
 241        return new_encode_dev(sbi->sb->s_dev);
 242}
 243
 244static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 245{
 246        return sbi->sb->s_root->d_inode->i_ino;
 247}
 248
 249static inline int simple_positive(struct dentry *dentry)
 250{
 251        return dentry->d_inode && !d_unhashed(dentry);
 252}
 253
 254static inline int __simple_empty(struct dentry *dentry)
 255{
 256        struct dentry *child;
 257        int ret = 0;
 258
 259        list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
 260                if (simple_positive(child))
 261                        goto out;
 262        ret = 1;
 263out:
 264        return ret;
 265}
 266
 267void autofs4_dentry_release(struct dentry *);
 268extern void autofs4_kill_sb(struct super_block *);
 269