fs/autofs4/autofs_i.h

   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...)                           \
  43 do {                                                    \
  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...)                       \
  52 do {                                                    \
  53         printk(KERN_WARNING "pid %d: %s: " fmt "\n",    \
  54                 current->pid, __func__, ##args);        \
  55 } while (0)
  56
  57 #define AUTOFS_ERROR(fmt, args...)                      \
  58 do {                                                    \
  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. */
  69 struct 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
  99 struct 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
 118 struct 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
 141 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 142 {
 143         return (struct autofs_sb_info *)(sb->s_fs_info);
 144 }
 145
 146 static 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
 155 static 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? */
 160 static 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
 173 static 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
 180 struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
 181 void autofs4_free_ino(struct autofs_info *);
 182
 183 /* Expiration */
 184 int is_autofs4_dentry(struct dentry *);
 185 int autofs4_expire_wait(struct dentry *dentry);
 186 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 187                         struct autofs_sb_info *,
 188                         struct autofs_packet_expire __user *);
 189 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 190                             struct autofs_sb_info *sbi, int when);
 191 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 192                         struct autofs_sb_info *, int __user *);
 193 struct dentry *autofs4_expire_direct(struct super_block *sb,
 194                                      struct vfsmount *mnt,
 195                                      struct autofs_sb_info *sbi, int how);
 196 struct 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
 202 int autofs_dev_ioctl_init(void);
 203 void autofs_dev_ioctl_exit(void);
 204
 205 /* Operations structures */
 206
 207 extern const struct inode_operations autofs4_symlink_inode_operations;
 208 extern const struct inode_operations autofs4_dir_inode_operations;
 209 extern const struct inode_operations autofs4_root_inode_operations;
 210 extern const struct inode_operations autofs4_indirect_root_inode_operations;
 211 extern const struct inode_operations autofs4_direct_root_inode_operations;
 212 extern const struct file_operations autofs4_dir_operations;
 213 extern const struct file_operations autofs4_root_operations;
 214
 215 /* Initializing function */
 216
 217 int autofs4_fill_super(struct super_block *, void *, int);
 218 struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
 219
 220 /* Queue management functions */
 221
 222 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 223 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 224 void autofs4_catatonic_mode(struct autofs_sb_info *);
 225
 226 static 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
 239 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 240 {
 241         return new_encode_dev(sbi->sb->s_dev);
 242 }
 243
 244 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 245 {
 246         return sbi->sb->s_root->d_inode->i_ino;
 247 }
 248
 249 static inline int simple_positive(struct dentry *dentry)
 250 {
 251         return dentry->d_inode && !d_unhashed(dentry);
 252 }
 253
 254 static 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;
 263 out:
 264         return ret;
 265 }
 266
 267 void autofs4_dentry_release(struct dentry *);
 268 extern void autofs4_kill_sb(struct super_block *);