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         mode_t  mode;
  93         size_t  size;
  94
  95         void (*free)(struct autofs_info *);
  96         union {
  97                 const char *symlink;
  98         } u;
  99 };
 100
 101 #define AUTOFS_INF_EXPIRING     (1<<0) /* dentry is in the process of expiring */
 102 #define AUTOFS_INF_PENDING      (1<<2) /* dentry pending mount */
 103
 104 struct autofs_wait_queue {
 105         wait_queue_head_t queue;
 106         struct autofs_wait_queue *next;
 107         autofs_wqt_t wait_queue_token;
 108         /* We use the following to see what we are waiting for */
 109         struct qstr name;
 110         u32 dev;
 111         u64 ino;
 112         uid_t uid;
 113         gid_t gid;
 114         pid_t pid;
 115         pid_t tgid;
 116         /* This is for status reporting upon return */
 117         int status;
 118         unsigned int wait_ctr;
 119 };
 120
 121 #define AUTOFS_SBI_MAGIC 0x6d4a556d
 122
 123 struct autofs_sb_info {
 124         u32 magic;
 125         int pipefd;
 126         struct file *pipe;
 127         pid_t oz_pgrp;
 128         int catatonic;
 129         int version;
 130         int sub_version;
 131         int min_proto;
 132         int max_proto;
 133         unsigned long exp_timeout;
 134         unsigned int type;
 135         int reghost_enabled;
 136         int needs_reghost;
 137         struct super_block *sb;
 138         struct mutex wq_mutex;
 139         spinlock_t fs_lock;
 140         struct autofs_wait_queue *queues; /* Wait queue pointer */
 141         spinlock_t lookup_lock;
 142         struct list_head active_list;
 143         struct list_head expiring_list;
 144 };
 145
 146 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 147 {
 148         return (struct autofs_sb_info *)(sb->s_fs_info);
 149 }
 150
 151 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 152 {
 153         return (struct autofs_info *)(dentry->d_fsdata);
 154 }
 155
 156 /* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 157    processes which do manipulations for us in user space sees the raw
 158    filesystem without "magic".) */
 159
 160 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 161         return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 162 }
 163
 164 /* Does a dentry have some pending activity? */
 165 static inline int autofs4_ispending(struct dentry *dentry)
 166 {
 167         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 168
 169         if (inf->flags & AUTOFS_INF_PENDING)
 170                 return 1;
 171
 172         if (inf->flags & AUTOFS_INF_EXPIRING)
 173                 return 1;
 174
 175         return 0;
 176 }
 177
 178 struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
 179 void autofs4_free_ino(struct autofs_info *);
 180
 181 /* Expiration */
 182 int is_autofs4_dentry(struct dentry *);
 183 int autofs4_expire_wait(struct dentry *dentry);
 184 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 185                         struct autofs_sb_info *,
 186                         struct autofs_packet_expire __user *);
 187 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 188                             struct autofs_sb_info *sbi, int when);
 189 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 190                         struct autofs_sb_info *, int __user *);
 191 struct dentry *autofs4_expire_direct(struct super_block *sb,
 192                                      struct vfsmount *mnt,
 193                                      struct autofs_sb_info *sbi, int how);
 194 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 195                                        struct vfsmount *mnt,
 196                                        struct autofs_sb_info *sbi, int how);
 197
 198 /* Device node initialization */
 199
 200 int autofs_dev_ioctl_init(void);
 201 void autofs_dev_ioctl_exit(void);
 202
 203 /* Operations structures */
 204
 205 extern const struct inode_operations autofs4_symlink_inode_operations;
 206 extern const struct inode_operations autofs4_dir_inode_operations;
 207 extern const struct file_operations autofs4_dir_operations;
 208 extern const struct file_operations autofs4_root_operations;
 209 extern const struct dentry_operations autofs4_dentry_operations;
 210
 211 /* VFS automount flags management functions */
 212
 213 static inline void __managed_dentry_set_automount(struct dentry *dentry)
 214 {
 215         dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 216 }
 217
 218 static inline void managed_dentry_set_automount(struct dentry *dentry)
 219 {
 220         spin_lock(&dentry->d_lock);
 221         __managed_dentry_set_automount(dentry);
 222         spin_unlock(&dentry->d_lock);
 223 }
 224
 225 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 226 {
 227         dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 228 }
 229
 230 static inline void managed_dentry_clear_automount(struct dentry *dentry)
 231 {
 232         spin_lock(&dentry->d_lock);
 233         __managed_dentry_clear_automount(dentry);
 234         spin_unlock(&dentry->d_lock);
 235 }
 236
 237 static inline void __managed_dentry_set_transit(struct dentry *dentry)
 238 {
 239         dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 240 }
 241
 242 static inline void managed_dentry_set_transit(struct dentry *dentry)
 243 {
 244         spin_lock(&dentry->d_lock);
 245         __managed_dentry_set_transit(dentry);
 246         spin_unlock(&dentry->d_lock);
 247 }
 248
 249 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 250 {
 251         dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 252 }
 253
 254 static inline void managed_dentry_clear_transit(struct dentry *dentry)
 255 {
 256         spin_lock(&dentry->d_lock);
 257         __managed_dentry_clear_transit(dentry);
 258         spin_unlock(&dentry->d_lock);
 259 }
 260
 261 static inline void __managed_dentry_set_managed(struct dentry *dentry)
 262 {
 263         dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 264 }
 265
 266 static inline void managed_dentry_set_managed(struct dentry *dentry)
 267 {
 268         spin_lock(&dentry->d_lock);
 269         __managed_dentry_set_managed(dentry);
 270         spin_unlock(&dentry->d_lock);
 271 }
 272
 273 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 274 {
 275         dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 276 }
 277
 278 static inline void managed_dentry_clear_managed(struct dentry *dentry)
 279 {
 280         spin_lock(&dentry->d_lock);
 281         __managed_dentry_clear_managed(dentry);
 282         spin_unlock(&dentry->d_lock);
 283 }
 284
 285 /* Initializing function */
 286
 287 int autofs4_fill_super(struct super_block *, void *, int);
 288 struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
 289
 290 /* Queue management functions */
 291
 292 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 293 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 294 void autofs4_catatonic_mode(struct autofs_sb_info *);
 295
 296 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 297 {
 298         return new_encode_dev(sbi->sb->s_dev);
 299 }
 300
 301 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 302 {
 303         return sbi->sb->s_root->d_inode->i_ino;
 304 }
 305
 306 static inline int simple_positive(struct dentry *dentry)
 307 {
 308         return dentry->d_inode && !d_unhashed(dentry);
 309 }
 310
 311 static inline void __autofs4_add_expiring(struct dentry *dentry)
 312 {
 313         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 314         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 315         if (ino) {
 316                 if (list_empty(&ino->expiring))
 317                         list_add(&ino->expiring, &sbi->expiring_list);
 318         }
 319         return;
 320 }
 321
 322 static inline void autofs4_add_expiring(struct dentry *dentry)
 323 {
 324         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 325         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 326         if (ino) {
 327                 spin_lock(&sbi->lookup_lock);
 328                 if (list_empty(&ino->expiring))
 329                         list_add(&ino->expiring, &sbi->expiring_list);
 330                 spin_unlock(&sbi->lookup_lock);
 331         }
 332         return;
 333 }
 334
 335 static inline void autofs4_del_expiring(struct dentry *dentry)
 336 {
 337         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 338         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 339         if (ino) {
 340                 spin_lock(&sbi->lookup_lock);
 341                 if (!list_empty(&ino->expiring))
 342                         list_del_init(&ino->expiring);
 343                 spin_unlock(&sbi->lookup_lock);
 344         }
 345         return;
 346 }
 347
 348 void autofs4_dentry_release(struct dentry *);
 349 extern void autofs4_kill_sb(struct super_block *);