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 /* Does a dentry have some pending activity? */
 147 static inline int autofs4_ispending(struct dentry *dentry)
 148 {
 149         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 150
 151         if (inf->flags & AUTOFS_INF_PENDING)
 152                 return 1;
 153
 154         if (inf->flags & AUTOFS_INF_EXPIRING)
 155                 return 1;
 156
 157         return 0;
 158 }
 159
 160 struct inode *autofs4_get_inode(struct super_block *, umode_t);
 161 void autofs4_free_ino(struct autofs_info *);
 162
 163 /* Expiration */
 164 int is_autofs4_dentry(struct dentry *);
 165 int autofs4_expire_wait(struct dentry *dentry);
 166 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 167                         struct autofs_sb_info *,
 168                         struct autofs_packet_expire __user *);
 169 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 170                             struct autofs_sb_info *sbi, int when);
 171 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 172                         struct autofs_sb_info *, int __user *);
 173 struct dentry *autofs4_expire_direct(struct super_block *sb,
 174                                      struct vfsmount *mnt,
 175                                      struct autofs_sb_info *sbi, int how);
 176 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 177                                        struct vfsmount *mnt,
 178                                        struct autofs_sb_info *sbi, int how);
 179
 180 /* Device node initialization */
 181
 182 int autofs_dev_ioctl_init(void);
 183 void autofs_dev_ioctl_exit(void);
 184
 185 /* Operations structures */
 186
 187 extern const struct inode_operations autofs4_symlink_inode_operations;
 188 extern const struct inode_operations autofs4_dir_inode_operations;
 189 extern const struct file_operations autofs4_dir_operations;
 190 extern const struct file_operations autofs4_root_operations;
 191 extern const struct dentry_operations autofs4_dentry_operations;
 192
 193 /* VFS automount flags management functions */
 194
 195 static inline void __managed_dentry_set_automount(struct dentry *dentry)
 196 {
 197         dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 198 }
 199
 200 static inline void managed_dentry_set_automount(struct dentry *dentry)
 201 {
 202         spin_lock(&dentry->d_lock);
 203         __managed_dentry_set_automount(dentry);
 204         spin_unlock(&dentry->d_lock);
 205 }
 206
 207 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 208 {
 209         dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 210 }
 211
 212 static inline void managed_dentry_clear_automount(struct dentry *dentry)
 213 {
 214         spin_lock(&dentry->d_lock);
 215         __managed_dentry_clear_automount(dentry);
 216         spin_unlock(&dentry->d_lock);
 217 }
 218
 219 static inline void __managed_dentry_set_transit(struct dentry *dentry)
 220 {
 221         dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 222 }
 223
 224 static inline void managed_dentry_set_transit(struct dentry *dentry)
 225 {
 226         spin_lock(&dentry->d_lock);
 227         __managed_dentry_set_transit(dentry);
 228         spin_unlock(&dentry->d_lock);
 229 }
 230
 231 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 232 {
 233         dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 234 }
 235
 236 static inline void managed_dentry_clear_transit(struct dentry *dentry)
 237 {
 238         spin_lock(&dentry->d_lock);
 239         __managed_dentry_clear_transit(dentry);
 240         spin_unlock(&dentry->d_lock);
 241 }
 242
 243 static inline void __managed_dentry_set_managed(struct dentry *dentry)
 244 {
 245         dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 246 }
 247
 248 static inline void managed_dentry_set_managed(struct dentry *dentry)
 249 {
 250         spin_lock(&dentry->d_lock);
 251         __managed_dentry_set_managed(dentry);
 252         spin_unlock(&dentry->d_lock);
 253 }
 254
 255 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 256 {
 257         dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 258 }
 259
 260 static inline void managed_dentry_clear_managed(struct dentry *dentry)
 261 {
 262         spin_lock(&dentry->d_lock);
 263         __managed_dentry_clear_managed(dentry);
 264         spin_unlock(&dentry->d_lock);
 265 }
 266
 267 /* Initializing function */
 268
 269 int autofs4_fill_super(struct super_block *, void *, int);
 270 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 271 void autofs4_clean_ino(struct autofs_info *);
 272
 273 static inline int autofs_prepare_pipe(struct file *pipe)
 274 {
 275         if (!pipe->f_op->write)
 276                 return -EINVAL;
 277         if (!S_ISFIFO(file_inode(pipe)->i_mode))
 278                 return -EINVAL;
 279         /* We want a packet pipe */
 280         pipe->f_flags |= O_DIRECT;
 281         return 0;
 282 }
 283
 284 /* Queue management functions */
 285
 286 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 287 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 288 void autofs4_catatonic_mode(struct autofs_sb_info *);
 289
 290 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 291 {
 292         return new_encode_dev(sbi->sb->s_dev);
 293 }
 294
 295 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 296 {
 297         return sbi->sb->s_root->d_inode->i_ino;
 298 }
 299
 300 static inline int simple_positive(struct dentry *dentry)
 301 {
 302         return dentry->d_inode && !d_unhashed(dentry);
 303 }
 304
 305 static inline void __autofs4_add_expiring(struct dentry *dentry)
 306 {
 307         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 308         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 309         if (ino) {
 310                 if (list_empty(&ino->expiring))
 311                         list_add(&ino->expiring, &sbi->expiring_list);
 312         }
 313         return;
 314 }
 315
 316 static inline void autofs4_add_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_add(&ino->expiring, &sbi->expiring_list);
 324                 spin_unlock(&sbi->lookup_lock);
 325         }
 326         return;
 327 }
 328
 329 static inline void autofs4_del_expiring(struct dentry *dentry)
 330 {
 331         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 332         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 333         if (ino) {
 334                 spin_lock(&sbi->lookup_lock);
 335                 if (!list_empty(&ino->expiring))
 336                         list_del_init(&ino->expiring);
 337                 spin_unlock(&sbi->lookup_lock);
 338         }
 339         return;
 340 }
 341
 342 extern void autofs4_kill_sb(struct super_block *);