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         uid_t uid;
  78         gid_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         uid_t uid;
  93         gid_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         pid_t 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         spinlock_t fs_lock;
 120         struct autofs_wait_queue *queues; /* Wait queue pointer */
 121         spinlock_t lookup_lock;
 122         struct list_head active_list;
 123         struct list_head expiring_list;
 124 };
 125
 126 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 127 {
 128         return (struct autofs_sb_info *)(sb->s_fs_info);
 129 }
 130
 131 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 132 {
 133         return (struct autofs_info *)(dentry->d_fsdata);
 134 }
 135
 136 /* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 137    processes which do manipulations for us in user space sees the raw
 138    filesystem without "magic".) */
 139
 140 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 141         return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 142 }
 143
 144 /* Does a dentry have some pending activity? */
 145 static inline int autofs4_ispending(struct dentry *dentry)
 146 {
 147         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 148
 149         if (inf->flags & AUTOFS_INF_PENDING)
 150                 return 1;
 151
 152         if (inf->flags & AUTOFS_INF_EXPIRING)
 153                 return 1;
 154
 155         return 0;
 156 }
 157
 158 struct inode *autofs4_get_inode(struct super_block *, mode_t);
 159 void autofs4_free_ino(struct autofs_info *);
 160
 161 /* Expiration */
 162 int is_autofs4_dentry(struct dentry *);
 163 int autofs4_expire_wait(struct dentry *dentry);
 164 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 165                         struct autofs_sb_info *,
 166                         struct autofs_packet_expire __user *);
 167 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 168                             struct autofs_sb_info *sbi, int when);
 169 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 170                         struct autofs_sb_info *, int __user *);
 171 struct dentry *autofs4_expire_direct(struct super_block *sb,
 172                                      struct vfsmount *mnt,
 173                                      struct autofs_sb_info *sbi, int how);
 174 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 175                                        struct vfsmount *mnt,
 176                                        struct autofs_sb_info *sbi, int how);
 177
 178 /* Device node initialization */
 179
 180 int autofs_dev_ioctl_init(void);
 181 void autofs_dev_ioctl_exit(void);
 182
 183 /* Operations structures */
 184
 185 extern const struct inode_operations autofs4_symlink_inode_operations;
 186 extern const struct inode_operations autofs4_dir_inode_operations;
 187 extern const struct file_operations autofs4_dir_operations;
 188 extern const struct file_operations autofs4_root_operations;
 189 extern const struct dentry_operations autofs4_dentry_operations;
 190
 191 /* VFS automount flags management functions */
 192
 193 static inline void __managed_dentry_set_automount(struct dentry *dentry)
 194 {
 195         dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 196 }
 197
 198 static inline void managed_dentry_set_automount(struct dentry *dentry)
 199 {
 200         spin_lock(&dentry->d_lock);
 201         __managed_dentry_set_automount(dentry);
 202         spin_unlock(&dentry->d_lock);
 203 }
 204
 205 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 206 {
 207         dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 208 }
 209
 210 static inline void managed_dentry_clear_automount(struct dentry *dentry)
 211 {
 212         spin_lock(&dentry->d_lock);
 213         __managed_dentry_clear_automount(dentry);
 214         spin_unlock(&dentry->d_lock);
 215 }
 216
 217 static inline void __managed_dentry_set_transit(struct dentry *dentry)
 218 {
 219         dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 220 }
 221
 222 static inline void managed_dentry_set_transit(struct dentry *dentry)
 223 {
 224         spin_lock(&dentry->d_lock);
 225         __managed_dentry_set_transit(dentry);
 226         spin_unlock(&dentry->d_lock);
 227 }
 228
 229 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 230 {
 231         dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 232 }
 233
 234 static inline void managed_dentry_clear_transit(struct dentry *dentry)
 235 {
 236         spin_lock(&dentry->d_lock);
 237         __managed_dentry_clear_transit(dentry);
 238         spin_unlock(&dentry->d_lock);
 239 }
 240
 241 static inline void __managed_dentry_set_managed(struct dentry *dentry)
 242 {
 243         dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 244 }
 245
 246 static inline void managed_dentry_set_managed(struct dentry *dentry)
 247 {
 248         spin_lock(&dentry->d_lock);
 249         __managed_dentry_set_managed(dentry);
 250         spin_unlock(&dentry->d_lock);
 251 }
 252
 253 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 254 {
 255         dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 256 }
 257
 258 static inline void managed_dentry_clear_managed(struct dentry *dentry)
 259 {
 260         spin_lock(&dentry->d_lock);
 261         __managed_dentry_clear_managed(dentry);
 262         spin_unlock(&dentry->d_lock);
 263 }
 264
 265 /* Initializing function */
 266
 267 int autofs4_fill_super(struct super_block *, void *, int);
 268 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 269 void autofs4_clean_ino(struct autofs_info *);
 270
 271 /* Queue management functions */
 272
 273 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 274 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 275 void autofs4_catatonic_mode(struct autofs_sb_info *);
 276
 277 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 278 {
 279         return new_encode_dev(sbi->sb->s_dev);
 280 }
 281
 282 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 283 {
 284         return sbi->sb->s_root->d_inode->i_ino;
 285 }
 286
 287 static inline int simple_positive(struct dentry *dentry)
 288 {
 289         return dentry->d_inode && !d_unhashed(dentry);
 290 }
 291
 292 static inline void __autofs4_add_expiring(struct dentry *dentry)
 293 {
 294         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 295         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 296         if (ino) {
 297                 if (list_empty(&ino->expiring))
 298                         list_add(&ino->expiring, &sbi->expiring_list);
 299         }
 300         return;
 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                 spin_lock(&sbi->lookup_lock);
 309                 if (list_empty(&ino->expiring))
 310                         list_add(&ino->expiring, &sbi->expiring_list);
 311                 spin_unlock(&sbi->lookup_lock);
 312         }
 313         return;
 314 }
 315
 316 static inline void autofs4_del_expiring(struct dentry *dentry)
 317 {
 318         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 319         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 320         if (ino) {
 321                 spin_lock(&sbi->lookup_lock);
 322                 if (!list_empty(&ino->expiring))
 323                         list_del_init(&ino->expiring);
 324                 spin_unlock(&sbi->lookup_lock);
 325         }
 326         return;
 327 }
 328
 329 extern void autofs4_kill_sb(struct super_block *);