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 /* Unified info structure.  This is pointed to by both the dentry and
  65    inode structures.  Each file in the filesystem has an instance of this
  66    structure.  It holds a reference to the dentry, so dentries are never
  67    flushed while the file exists.  All name lookups are dealt with at the
  68    dentry level, although the filesystem can interfere in the validation
  69    process.  Readdir is implemented by traversing the dentry lists. */
  70 struct autofs_info {
  71         struct dentry   *dentry;
  72         struct inode    *inode;
  73
  74         int             flags;
  75
  76         struct completion expire_complete;
  77
  78         struct list_head active;
  79         int active_count;
  80
  81         struct list_head expiring;
  82
  83         struct autofs_sb_info *sbi;
  84         unsigned long last_used;
  85         atomic_t count;
  86
  87         uid_t uid;
  88         gid_t gid;
  89 };
  90
  91 #define AUTOFS_INF_EXPIRING     (1<<0) /* dentry is in the process of expiring */
  92 #define AUTOFS_INF_PENDING      (1<<2) /* dentry pending mount */
  93
  94 struct autofs_wait_queue {
  95         wait_queue_head_t queue;
  96         struct autofs_wait_queue *next;
  97         autofs_wqt_t wait_queue_token;
  98         /* We use the following to see what we are waiting for */
  99         struct qstr name;
 100         u32 dev;
 101         u64 ino;
 102         uid_t uid;
 103         gid_t gid;
 104         pid_t pid;
 105         pid_t tgid;
 106         /* This is for status reporting upon return */
 107         int status;
 108         unsigned int wait_ctr;
 109 };
 110
 111 #define AUTOFS_SBI_MAGIC 0x6d4a556d
 112
 113 struct autofs_sb_info {
 114         u32 magic;
 115         int pipefd;
 116         struct file *pipe;
 117         pid_t oz_pgrp;
 118         int catatonic;
 119         int version;
 120         int sub_version;
 121         int min_proto;
 122         int max_proto;
 123         unsigned long exp_timeout;
 124         unsigned int type;
 125         int reghost_enabled;
 126         int needs_reghost;
 127         struct super_block *sb;
 128         struct mutex wq_mutex;
 129         spinlock_t fs_lock;
 130         struct autofs_wait_queue *queues; /* Wait queue pointer */
 131         spinlock_t lookup_lock;
 132         struct list_head active_list;
 133         struct list_head expiring_list;
 134 };
 135
 136 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 137 {
 138         return (struct autofs_sb_info *)(sb->s_fs_info);
 139 }
 140
 141 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 142 {
 143         return (struct autofs_info *)(dentry->d_fsdata);
 144 }
 145
 146 /* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 147    processes which do manipulations for us in user space sees the raw
 148    filesystem without "magic".) */
 149
 150 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 151         return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 152 }
 153
 154 /* Does a dentry have some pending activity? */
 155 static inline int autofs4_ispending(struct dentry *dentry)
 156 {
 157         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 158
 159         if (inf->flags & AUTOFS_INF_PENDING)
 160                 return 1;
 161
 162         if (inf->flags & AUTOFS_INF_EXPIRING)
 163                 return 1;
 164
 165         return 0;
 166 }
 167
 168 struct inode *autofs4_get_inode(struct super_block *, mode_t);
 169 void autofs4_free_ino(struct autofs_info *);
 170
 171 /* Expiration */
 172 int is_autofs4_dentry(struct dentry *);
 173 int autofs4_expire_wait(struct dentry *dentry);
 174 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 175                         struct autofs_sb_info *,
 176                         struct autofs_packet_expire __user *);
 177 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 178                             struct autofs_sb_info *sbi, int when);
 179 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 180                         struct autofs_sb_info *, int __user *);
 181 struct dentry *autofs4_expire_direct(struct super_block *sb,
 182                                      struct vfsmount *mnt,
 183                                      struct autofs_sb_info *sbi, int how);
 184 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 185                                        struct vfsmount *mnt,
 186                                        struct autofs_sb_info *sbi, int how);
 187
 188 /* Device node initialization */
 189
 190 int autofs_dev_ioctl_init(void);
 191 void autofs_dev_ioctl_exit(void);
 192
 193 /* Operations structures */
 194
 195 extern const struct inode_operations autofs4_symlink_inode_operations;
 196 extern const struct inode_operations autofs4_dir_inode_operations;
 197 extern const struct file_operations autofs4_dir_operations;
 198 extern const struct file_operations autofs4_root_operations;
 199 extern const struct dentry_operations autofs4_dentry_operations;
 200
 201 /* VFS automount flags management functions */
 202
 203 static inline void __managed_dentry_set_automount(struct dentry *dentry)
 204 {
 205         dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 206 }
 207
 208 static inline void managed_dentry_set_automount(struct dentry *dentry)
 209 {
 210         spin_lock(&dentry->d_lock);
 211         __managed_dentry_set_automount(dentry);
 212         spin_unlock(&dentry->d_lock);
 213 }
 214
 215 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 216 {
 217         dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 218 }
 219
 220 static inline void managed_dentry_clear_automount(struct dentry *dentry)
 221 {
 222         spin_lock(&dentry->d_lock);
 223         __managed_dentry_clear_automount(dentry);
 224         spin_unlock(&dentry->d_lock);
 225 }
 226
 227 static inline void __managed_dentry_set_transit(struct dentry *dentry)
 228 {
 229         dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 230 }
 231
 232 static inline void managed_dentry_set_transit(struct dentry *dentry)
 233 {
 234         spin_lock(&dentry->d_lock);
 235         __managed_dentry_set_transit(dentry);
 236         spin_unlock(&dentry->d_lock);
 237 }
 238
 239 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 240 {
 241         dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 242 }
 243
 244 static inline void managed_dentry_clear_transit(struct dentry *dentry)
 245 {
 246         spin_lock(&dentry->d_lock);
 247         __managed_dentry_clear_transit(dentry);
 248         spin_unlock(&dentry->d_lock);
 249 }
 250
 251 static inline void __managed_dentry_set_managed(struct dentry *dentry)
 252 {
 253         dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 254 }
 255
 256 static inline void managed_dentry_set_managed(struct dentry *dentry)
 257 {
 258         spin_lock(&dentry->d_lock);
 259         __managed_dentry_set_managed(dentry);
 260         spin_unlock(&dentry->d_lock);
 261 }
 262
 263 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 264 {
 265         dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 266 }
 267
 268 static inline void managed_dentry_clear_managed(struct dentry *dentry)
 269 {
 270         spin_lock(&dentry->d_lock);
 271         __managed_dentry_clear_managed(dentry);
 272         spin_unlock(&dentry->d_lock);
 273 }
 274
 275 /* Initializing function */
 276
 277 int autofs4_fill_super(struct super_block *, void *, int);
 278 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 279 void autofs4_clean_ino(struct autofs_info *);
 280
 281 /* Queue management functions */
 282
 283 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 284 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 285 void autofs4_catatonic_mode(struct autofs_sb_info *);
 286
 287 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 288 {
 289         return new_encode_dev(sbi->sb->s_dev);
 290 }
 291
 292 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 293 {
 294         return sbi->sb->s_root->d_inode->i_ino;
 295 }
 296
 297 static inline int simple_positive(struct dentry *dentry)
 298 {
 299         return dentry->d_inode && !d_unhashed(dentry);
 300 }
 301
 302 static inline void __autofs4_add_expiring(struct dentry *dentry)
 303 {
 304         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 305         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 306         if (ino) {
 307                 if (list_empty(&ino->expiring))
 308                         list_add(&ino->expiring, &sbi->expiring_list);
 309         }
 310         return;
 311 }
 312
 313 static inline void autofs4_add_expiring(struct dentry *dentry)
 314 {
 315         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 316         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 317         if (ino) {
 318                 spin_lock(&sbi->lookup_lock);
 319                 if (list_empty(&ino->expiring))
 320                         list_add(&ino->expiring, &sbi->expiring_list);
 321                 spin_unlock(&sbi->lookup_lock);
 322         }
 323         return;
 324 }
 325
 326 static inline void autofs4_del_expiring(struct dentry *dentry)
 327 {
 328         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 329         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 330         if (ino) {
 331                 spin_lock(&sbi->lookup_lock);
 332                 if (!list_empty(&ino->expiring))
 333                         list_del_init(&ino->expiring);
 334                 spin_unlock(&sbi->lookup_lock);
 335         }
 336         return;
 337 }
 338
 339 extern void autofs4_kill_sb(struct super_block *);