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 #ifdef DEBUG
  43 #define DPRINTK(fmt, args...)                           \
  44 do {                                                    \
  45         printk(KERN_DEBUG "pid %d: %s: " fmt "\n",      \
  46                 current->pid, __func__, ##args);        \
  47 } while (0)
  48 #else
  49 #define DPRINTK(fmt, args...) do {} while (0)
  50 #endif
  51
  52 #define AUTOFS_WARN(fmt, args...)                       \
  53 do {                                                    \
  54         printk(KERN_WARNING "pid %d: %s: " fmt "\n",    \
  55                 current->pid, __func__, ##args);        \
  56 } while (0)
  57
  58 #define AUTOFS_ERROR(fmt, args...)                      \
  59 do {                                                    \
  60         printk(KERN_ERR "pid %d: %s: " fmt "\n",        \
  61                 current->pid, __func__, ##args);        \
  62 } while (0)
  63
  64 extern spinlock_t autofs4_lock;
  65
  66 /* Unified info structure.  This is pointed to by both the dentry and
  67    inode structures.  Each file in the filesystem has an instance of this
  68    structure.  It holds a reference to the dentry, so dentries are never
  69    flushed while the file exists.  All name lookups are dealt with at the
  70    dentry level, although the filesystem can interfere in the validation
  71    process.  Readdir is implemented by traversing the dentry lists. */
  72 struct autofs_info {
  73         struct dentry   *dentry;
  74         struct inode    *inode;
  75
  76         int             flags;
  77
  78         struct completion expire_complete;
  79
  80         struct list_head active;
  81         int active_count;
  82
  83         struct list_head expiring;
  84
  85         struct autofs_sb_info *sbi;
  86         unsigned long last_used;
  87         atomic_t count;
  88
  89         uid_t uid;
  90         gid_t gid;
  91 };
  92
  93 #define AUTOFS_INF_EXPIRING     (1<<0) /* dentry is in the process of expiring */
  94 #define AUTOFS_INF_PENDING      (1<<2) /* dentry pending mount */
  95
  96 struct autofs_wait_queue {
  97         wait_queue_head_t queue;
  98         struct autofs_wait_queue *next;
  99         autofs_wqt_t wait_queue_token;
 100         /* We use the following to see what we are waiting for */
 101         struct qstr name;
 102         u32 dev;
 103         u64 ino;
 104         uid_t uid;
 105         gid_t gid;
 106         pid_t pid;
 107         pid_t tgid;
 108         /* This is for status reporting upon return */
 109         int status;
 110         unsigned int wait_ctr;
 111 };
 112
 113 #define AUTOFS_SBI_MAGIC 0x6d4a556d
 114
 115 struct autofs_sb_info {
 116         u32 magic;
 117         int pipefd;
 118         struct file *pipe;
 119         pid_t oz_pgrp;
 120         int catatonic;
 121         int version;
 122         int sub_version;
 123         int min_proto;
 124         int max_proto;
 125         unsigned long exp_timeout;
 126         unsigned int type;
 127         int reghost_enabled;
 128         int needs_reghost;
 129         struct super_block *sb;
 130         struct mutex wq_mutex;
 131         spinlock_t fs_lock;
 132         struct autofs_wait_queue *queues; /* Wait queue pointer */
 133         spinlock_t lookup_lock;
 134         struct list_head active_list;
 135         struct list_head expiring_list;
 136 };
 137
 138 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 139 {
 140         return (struct autofs_sb_info *)(sb->s_fs_info);
 141 }
 142
 143 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 144 {
 145         return (struct autofs_info *)(dentry->d_fsdata);
 146 }
 147
 148 /* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 149    processes which do manipulations for us in user space sees the raw
 150    filesystem without "magic".) */
 151
 152 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 153         return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 154 }
 155
 156 /* Does a dentry have some pending activity? */
 157 static inline int autofs4_ispending(struct dentry *dentry)
 158 {
 159         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 160
 161         if (inf->flags & AUTOFS_INF_PENDING)
 162                 return 1;
 163
 164         if (inf->flags & AUTOFS_INF_EXPIRING)
 165                 return 1;
 166
 167         return 0;
 168 }
 169
 170 struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *, mode_t);
 171 void autofs4_free_ino(struct autofs_info *);
 172
 173 /* Expiration */
 174 int is_autofs4_dentry(struct dentry *);
 175 int autofs4_expire_wait(struct dentry *dentry);
 176 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 177                         struct autofs_sb_info *,
 178                         struct autofs_packet_expire __user *);
 179 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 180                             struct autofs_sb_info *sbi, int when);
 181 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 182                         struct autofs_sb_info *, int __user *);
 183 struct dentry *autofs4_expire_direct(struct super_block *sb,
 184                                      struct vfsmount *mnt,
 185                                      struct autofs_sb_info *sbi, int how);
 186 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 187                                        struct vfsmount *mnt,
 188                                        struct autofs_sb_info *sbi, int how);
 189
 190 /* Device node initialization */
 191
 192 int autofs_dev_ioctl_init(void);
 193 void autofs_dev_ioctl_exit(void);
 194
 195 /* Operations structures */
 196
 197 extern const struct inode_operations autofs4_symlink_inode_operations;
 198 extern const struct inode_operations autofs4_dir_inode_operations;
 199 extern const struct file_operations autofs4_dir_operations;
 200 extern const struct file_operations autofs4_root_operations;
 201 extern const struct dentry_operations autofs4_dentry_operations;
 202
 203 /* VFS automount flags management functions */
 204
 205 static inline void __managed_dentry_set_automount(struct dentry *dentry)
 206 {
 207         dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 208 }
 209
 210 static inline void managed_dentry_set_automount(struct dentry *dentry)
 211 {
 212         spin_lock(&dentry->d_lock);
 213         __managed_dentry_set_automount(dentry);
 214         spin_unlock(&dentry->d_lock);
 215 }
 216
 217 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 218 {
 219         dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 220 }
 221
 222 static inline void managed_dentry_clear_automount(struct dentry *dentry)
 223 {
 224         spin_lock(&dentry->d_lock);
 225         __managed_dentry_clear_automount(dentry);
 226         spin_unlock(&dentry->d_lock);
 227 }
 228
 229 static inline void __managed_dentry_set_transit(struct dentry *dentry)
 230 {
 231         dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 232 }
 233
 234 static inline void managed_dentry_set_transit(struct dentry *dentry)
 235 {
 236         spin_lock(&dentry->d_lock);
 237         __managed_dentry_set_transit(dentry);
 238         spin_unlock(&dentry->d_lock);
 239 }
 240
 241 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 242 {
 243         dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 244 }
 245
 246 static inline void managed_dentry_clear_transit(struct dentry *dentry)
 247 {
 248         spin_lock(&dentry->d_lock);
 249         __managed_dentry_clear_transit(dentry);
 250         spin_unlock(&dentry->d_lock);
 251 }
 252
 253 static inline void __managed_dentry_set_managed(struct dentry *dentry)
 254 {
 255         dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 256 }
 257
 258 static inline void managed_dentry_set_managed(struct dentry *dentry)
 259 {
 260         spin_lock(&dentry->d_lock);
 261         __managed_dentry_set_managed(dentry);
 262         spin_unlock(&dentry->d_lock);
 263 }
 264
 265 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 266 {
 267         dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 268 }
 269
 270 static inline void managed_dentry_clear_managed(struct dentry *dentry)
 271 {
 272         spin_lock(&dentry->d_lock);
 273         __managed_dentry_clear_managed(dentry);
 274         spin_unlock(&dentry->d_lock);
 275 }
 276
 277 /* Initializing function */
 278
 279 int autofs4_fill_super(struct super_block *, void *, int);
 280 struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi);
 281
 282 /* Queue management functions */
 283
 284 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 285 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 286 void autofs4_catatonic_mode(struct autofs_sb_info *);
 287
 288 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 289 {
 290         return new_encode_dev(sbi->sb->s_dev);
 291 }
 292
 293 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 294 {
 295         return sbi->sb->s_root->d_inode->i_ino;
 296 }
 297
 298 static inline int simple_positive(struct dentry *dentry)
 299 {
 300         return dentry->d_inode && !d_unhashed(dentry);
 301 }
 302
 303 static inline void __autofs4_add_expiring(struct dentry *dentry)
 304 {
 305         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 306         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 307         if (ino) {
 308                 if (list_empty(&ino->expiring))
 309                         list_add(&ino->expiring, &sbi->expiring_list);
 310         }
 311         return;
 312 }
 313
 314 static inline void autofs4_add_expiring(struct dentry *dentry)
 315 {
 316         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 317         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 318         if (ino) {
 319                 spin_lock(&sbi->lookup_lock);
 320                 if (list_empty(&ino->expiring))
 321                         list_add(&ino->expiring, &sbi->expiring_list);
 322                 spin_unlock(&sbi->lookup_lock);
 323         }
 324         return;
 325 }
 326
 327 static inline void autofs4_del_expiring(struct dentry *dentry)
 328 {
 329         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 330         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 331         if (ino) {
 332                 spin_lock(&sbi->lookup_lock);
 333                 if (!list_empty(&ino->expiring))
 334                         list_del_init(&ino->expiring);
 335                 spin_unlock(&sbi->lookup_lock);
 336         }
 337         return;
 338 }
 339
 340 void autofs4_dentry_release(struct dentry *);
 341 extern void autofs4_kill_sb(struct super_block *);