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         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         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 };
 126
 127 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 128 {
 129         return (struct autofs_sb_info *)(sb->s_fs_info);
 130 }
 131
 132 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 133 {
 134         return (struct autofs_info *)(dentry->d_fsdata);
 135 }
 136
 137 /* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 138    processes which do manipulations for us in user space sees the raw
 139    filesystem without "magic".) */
 140
 141 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 142         return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 143 }
 144
 145 /* Does a dentry have some pending activity? */
 146 static inline int autofs4_ispending(struct dentry *dentry)
 147 {
 148         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 149
 150         if (inf->flags & AUTOFS_INF_PENDING)
 151                 return 1;
 152
 153         if (inf->flags & AUTOFS_INF_EXPIRING)
 154                 return 1;
 155
 156         return 0;
 157 }
 158
 159 struct inode *autofs4_get_inode(struct super_block *, umode_t);
 160 void autofs4_free_ino(struct autofs_info *);
 161
 162 /* Expiration */
 163 int is_autofs4_dentry(struct dentry *);
 164 int autofs4_expire_wait(struct dentry *dentry);
 165 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 166                         struct autofs_sb_info *,
 167                         struct autofs_packet_expire __user *);
 168 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 169                             struct autofs_sb_info *sbi, int when);
 170 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 171                         struct autofs_sb_info *, int __user *);
 172 struct dentry *autofs4_expire_direct(struct super_block *sb,
 173                                      struct vfsmount *mnt,
 174                                      struct autofs_sb_info *sbi, int how);
 175 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 176                                        struct vfsmount *mnt,
 177                                        struct autofs_sb_info *sbi, int how);
 178
 179 /* Device node initialization */
 180
 181 int autofs_dev_ioctl_init(void);
 182 void autofs_dev_ioctl_exit(void);
 183
 184 /* Operations structures */
 185
 186 extern const struct inode_operations autofs4_symlink_inode_operations;
 187 extern const struct inode_operations autofs4_dir_inode_operations;
 188 extern const struct file_operations autofs4_dir_operations;
 189 extern const struct file_operations autofs4_root_operations;
 190 extern const struct dentry_operations autofs4_dentry_operations;
 191
 192 /* VFS automount flags management functions */
 193
 194 static inline void __managed_dentry_set_automount(struct dentry *dentry)
 195 {
 196         dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 197 }
 198
 199 static inline void managed_dentry_set_automount(struct dentry *dentry)
 200 {
 201         spin_lock(&dentry->d_lock);
 202         __managed_dentry_set_automount(dentry);
 203         spin_unlock(&dentry->d_lock);
 204 }
 205
 206 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
 207 {
 208         dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
 209 }
 210
 211 static inline void managed_dentry_clear_automount(struct dentry *dentry)
 212 {
 213         spin_lock(&dentry->d_lock);
 214         __managed_dentry_clear_automount(dentry);
 215         spin_unlock(&dentry->d_lock);
 216 }
 217
 218 static inline void __managed_dentry_set_transit(struct dentry *dentry)
 219 {
 220         dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
 221 }
 222
 223 static inline void managed_dentry_set_transit(struct dentry *dentry)
 224 {
 225         spin_lock(&dentry->d_lock);
 226         __managed_dentry_set_transit(dentry);
 227         spin_unlock(&dentry->d_lock);
 228 }
 229
 230 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
 231 {
 232         dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
 233 }
 234
 235 static inline void managed_dentry_clear_transit(struct dentry *dentry)
 236 {
 237         spin_lock(&dentry->d_lock);
 238         __managed_dentry_clear_transit(dentry);
 239         spin_unlock(&dentry->d_lock);
 240 }
 241
 242 static inline void __managed_dentry_set_managed(struct dentry *dentry)
 243 {
 244         dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 245 }
 246
 247 static inline void managed_dentry_set_managed(struct dentry *dentry)
 248 {
 249         spin_lock(&dentry->d_lock);
 250         __managed_dentry_set_managed(dentry);
 251         spin_unlock(&dentry->d_lock);
 252 }
 253
 254 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
 255 {
 256         dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
 257 }
 258
 259 static inline void managed_dentry_clear_managed(struct dentry *dentry)
 260 {
 261         spin_lock(&dentry->d_lock);
 262         __managed_dentry_clear_managed(dentry);
 263         spin_unlock(&dentry->d_lock);
 264 }
 265
 266 /* Initializing function */
 267
 268 int autofs4_fill_super(struct super_block *, void *, int);
 269 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 270 void autofs4_clean_ino(struct autofs_info *);
 271
 272 static inline int autofs_prepare_pipe(struct file *pipe)
 273 {
 274         if (!pipe->f_op || !pipe->f_op->write)
 275                 return -EINVAL;
 276         if (!S_ISFIFO(file_inode(pipe)->i_mode))
 277                 return -EINVAL;
 278         /* We want a packet pipe */
 279         pipe->f_flags |= O_DIRECT;
 280         return 0;
 281 }
 282
 283 /* Queue management functions */
 284
 285 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 286 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 287 void autofs4_catatonic_mode(struct autofs_sb_info *);
 288
 289 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 290 {
 291         return new_encode_dev(sbi->sb->s_dev);
 292 }
 293
 294 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 295 {
 296         return sbi->sb->s_root->d_inode->i_ino;
 297 }
 298
 299 static inline int simple_positive(struct dentry *dentry)
 300 {
 301         return dentry->d_inode && !d_unhashed(dentry);
 302 }
 303
 304 static inline void __autofs4_add_expiring(struct dentry *dentry)
 305 {
 306         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 307         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 308         if (ino) {
 309                 if (list_empty(&ino->expiring))
 310                         list_add(&ino->expiring, &sbi->expiring_list);
 311         }
 312         return;
 313 }
 314
 315 static inline void autofs4_add_expiring(struct dentry *dentry)
 316 {
 317         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 318         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 319         if (ino) {
 320                 spin_lock(&sbi->lookup_lock);
 321                 if (list_empty(&ino->expiring))
 322                         list_add(&ino->expiring, &sbi->expiring_list);
 323                 spin_unlock(&sbi->lookup_lock);
 324         }
 325         return;
 326 }
 327
 328 static inline void autofs4_del_expiring(struct dentry *dentry)
 329 {
 330         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 331         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 332         if (ino) {
 333                 spin_lock(&sbi->lookup_lock);
 334                 if (!list_empty(&ino->expiring))
 335                         list_del_init(&ino->expiring);
 336                 spin_unlock(&sbi->lookup_lock);
 337         }
 338         return;
 339 }
 340
 341 extern void autofs4_kill_sb(struct super_block *);