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         int compat_daemon;
 129         unsigned long exp_timeout;
 130         unsigned int type;
 131         int reghost_enabled;
 132         int needs_reghost;
 133         struct super_block *sb;
 134         struct mutex wq_mutex;
 135         spinlock_t fs_lock;
 136         struct autofs_wait_queue *queues; /* Wait queue pointer */
 137         spinlock_t lookup_lock;
 138         struct list_head active_list;
 139         struct list_head expiring_list;
 140 };
 141
 142 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 143 {
 144         return (struct autofs_sb_info *)(sb->s_fs_info);
 145 }
 146
 147 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 148 {
 149         return (struct autofs_info *)(dentry->d_fsdata);
 150 }
 151
 152 /* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 153    processes which do manipulations for us in user space sees the raw
 154    filesystem without "magic".) */
 155
 156 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 157         return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 158 }
 159
 160 /* Does a dentry have some pending activity? */
 161 static inline int autofs4_ispending(struct dentry *dentry)
 162 {
 163         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 164
 165         if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
 166                 return 1;
 167
 168         if (inf->flags & AUTOFS_INF_EXPIRING)
 169                 return 1;
 170
 171         return 0;
 172 }
 173
 174 static inline void autofs4_copy_atime(struct file *src, struct file *dst)
 175 {
 176         dst->f_path.dentry->d_inode->i_atime =
 177                 src->f_path.dentry->d_inode->i_atime;
 178         return;
 179 }
 180
 181 struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
 182 void autofs4_free_ino(struct autofs_info *);
 183
 184 /* Expiration */
 185 int is_autofs4_dentry(struct dentry *);
 186 int autofs4_expire_wait(struct dentry *dentry);
 187 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 188                         struct autofs_sb_info *,
 189                         struct autofs_packet_expire __user *);
 190 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 191                             struct autofs_sb_info *sbi, int when);
 192 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 193                         struct autofs_sb_info *, int __user *);
 194 struct dentry *autofs4_expire_direct(struct super_block *sb,
 195                                      struct vfsmount *mnt,
 196                                      struct autofs_sb_info *sbi, int how);
 197 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 198                                        struct vfsmount *mnt,
 199                                        struct autofs_sb_info *sbi, int how);
 200
 201 /* Device node initialization */
 202
 203 int autofs_dev_ioctl_init(void);
 204 void autofs_dev_ioctl_exit(void);
 205
 206 /* Operations structures */
 207
 208 extern const struct inode_operations autofs4_symlink_inode_operations;
 209 extern const struct inode_operations autofs4_dir_inode_operations;
 210 extern const struct inode_operations autofs4_root_inode_operations;
 211 extern const struct inode_operations autofs4_indirect_root_inode_operations;
 212 extern const struct inode_operations autofs4_direct_root_inode_operations;
 213 extern const struct file_operations autofs4_dir_operations;
 214 extern const struct file_operations autofs4_root_operations;
 215
 216 /* Initializing function */
 217
 218 int autofs4_fill_super(struct super_block *, void *, int);
 219 struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
 220
 221 /* Queue management functions */
 222
 223 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 224 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 225 void autofs4_catatonic_mode(struct autofs_sb_info *);
 226
 227 static inline int autofs4_follow_mount(struct path *path)
 228 {
 229         int res = 0;
 230
 231         while (d_mountpoint(path->dentry)) {
 232                 int followed = follow_down(path);
 233                 if (!followed)
 234                         break;
 235                 res = 1;
 236         }
 237         return res;
 238 }
 239
 240 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 241 {
 242         return new_encode_dev(sbi->sb->s_dev);
 243 }
 244
 245 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 246 {
 247         return sbi->sb->s_root->d_inode->i_ino;
 248 }
 249
 250 static inline int simple_positive(struct dentry *dentry)
 251 {
 252         return dentry->d_inode && !d_unhashed(dentry);
 253 }
 254
 255 static inline int __simple_empty(struct dentry *dentry)
 256 {
 257         struct dentry *child;
 258         int ret = 0;
 259
 260         list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
 261                 if (simple_positive(child))
 262                         goto out;
 263         ret = 1;
 264 out:
 265         return ret;
 266 }
 267
 268 void autofs4_dentry_release(struct dentry *);
 269 extern void autofs4_kill_sb(struct super_block *);