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/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. */
  60 struct 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         kuid_t uid;
  78         kgid_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
  84 struct 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         kuid_t uid;
  93         kgid_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
 103 struct autofs_sb_info {
 104         u32 magic;
 105         int pipefd;
 106         struct file *pipe;
 107         struct pid *oz_pgrp;
 108         int catatonic;
 109         int version;
 110         int sub_version;
 111         int min_proto;
 112         int max_proto;
 113         unsigned long exp_timeout;
 114         unsigned int type;
 115         int reghost_enabled;
 116         int needs_reghost;
 117         struct super_block *sb;
 118         struct mutex wq_mutex;
 119         struct mutex pipe_mutex;
 120         spinlock_t fs_lock;
 121         struct autofs_wait_queue *queues; /* Wait queue pointer */
 122         spinlock_t lookup_lock;
 123         struct list_head active_list;
 124         struct list_head expiring_list;
 125         struct rcu_head rcu;
 126 };
 127
 128 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 129 {
 130         return (struct autofs_sb_info *)(sb->s_fs_info);
 131 }
 132
 133 static 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
 142 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 143         return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
 144 }
 145
 146 struct inode *autofs4_get_inode(struct super_block *, umode_t);
 147 void autofs4_free_ino(struct autofs_info *);
 148
 149 /* Expiration */
 150 int is_autofs4_dentry(struct dentry *);
 151 int autofs4_expire_wait(struct dentry *dentry, int rcu_walk);
 152 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 153                         struct autofs_sb_info *,
 154                         struct autofs_packet_expire __user *);
 155 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 156                             struct autofs_sb_info *sbi, int when);
 157 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 158                         struct autofs_sb_info *, int __user *);
 159 struct dentry *autofs4_expire_direct(struct super_block *sb,
 160                                      struct vfsmount *mnt,
 161                                      struct autofs_sb_info *sbi, int how);
 162 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 163                                        struct vfsmount *mnt,
 164                                        struct autofs_sb_info *sbi, int how);
 165
 166 /* Device node initialization */
 167
 168 int autofs_dev_ioctl_init(void);
 169 void autofs_dev_ioctl_exit(void);
 170
 171 /* Operations structures */
 172
 173 extern const struct inode_operations autofs4_symlink_inode_operations;
 174 extern const struct inode_operations autofs4_dir_inode_operations;
 175 extern const struct file_operations autofs4_dir_operations;
 176 extern const struct file_operations autofs4_root_operations;
 177 extern const struct dentry_operations autofs4_dentry_operations;
 178
 179 /* VFS automount flags management functions */
 180 static inline void __managed_dentry_set_managed(struct dentry *dentry)
 181 {
 182         dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 183 }
 184
 185 static inline void managed_dentry_set_managed(struct dentry *dentry)
 186 {
 187         spin_lock(&dentry->d_lock);
 188         __managed_dentry_set_managed(dentry);
 189         spin_unlock(&dentry->d_lock);
 190 }
 191
 192 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 193 {
 194         dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 195 }
 196
 197 static inline void managed_dentry_clear_managed(struct dentry *dentry)
 198 {
 199         spin_lock(&dentry->d_lock);
 200         __managed_dentry_clear_managed(dentry);
 201         spin_unlock(&dentry->d_lock);
 202 }
 203
 204 /* Initializing function */
 205
 206 int autofs4_fill_super(struct super_block *, void *, int);
 207 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 208 void autofs4_clean_ino(struct autofs_info *);
 209
 210 static inline int autofs_prepare_pipe(struct file *pipe)
 211 {
 212         if (!pipe->f_op->write)
 213                 return -EINVAL;
 214         if (!S_ISFIFO(file_inode(pipe)->i_mode))
 215                 return -EINVAL;
 216         /* We want a packet pipe */
 217         pipe->f_flags |= O_DIRECT;
 218         return 0;
 219 }
 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 u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 228 {
 229         return new_encode_dev(sbi->sb->s_dev);
 230 }
 231
 232 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 233 {
 234         return sbi->sb->s_root->d_inode->i_ino;
 235 }
 236
 237 static inline int simple_positive(struct dentry *dentry)
 238 {
 239         return dentry->d_inode && !d_unhashed(dentry);
 240 }
 241
 242 static inline void __autofs4_add_expiring(struct dentry *dentry)
 243 {
 244         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 245         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 246         if (ino) {
 247                 if (list_empty(&ino->expiring))
 248                         list_add(&ino->expiring, &sbi->expiring_list);
 249         }
 250         return;
 251 }
 252
 253 static inline void autofs4_add_expiring(struct dentry *dentry)
 254 {
 255         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 256         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 257         if (ino) {
 258                 spin_lock(&sbi->lookup_lock);
 259                 if (list_empty(&ino->expiring))
 260                         list_add(&ino->expiring, &sbi->expiring_list);
 261                 spin_unlock(&sbi->lookup_lock);
 262         }
 263         return;
 264 }
 265
 266 static inline void autofs4_del_expiring(struct dentry *dentry)
 267 {
 268         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 269         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 270         if (ino) {
 271                 spin_lock(&sbi->lookup_lock);
 272                 if (!list_empty(&ino->expiring))
 273                         list_del_init(&ino->expiring);
 274                 spin_unlock(&sbi->lookup_lock);
 275         }
 276         return;
 277 }
 278
 279 extern void autofs4_kill_sb(struct super_block *);