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_MOUNTPOINT   (1<<1) /* mountpoint status for direct expire */
 103 #define AUTOFS_INF_PENDING      (1<<2) /* dentry pending mount */
 104
 105 struct autofs_wait_queue {
 106         wait_queue_head_t queue;
 107         struct autofs_wait_queue *next;
 108         autofs_wqt_t wait_queue_token;
 109         /* We use the following to see what we are waiting for */
 110         struct qstr name;
 111         u32 dev;
 112         u64 ino;
 113         uid_t uid;
 114         gid_t gid;
 115         pid_t pid;
 116         pid_t tgid;
 117         /* This is for status reporting upon return */
 118         int status;
 119         unsigned int wait_ctr;
 120 };
 121
 122 #define AUTOFS_SBI_MAGIC 0x6d4a556d
 123
 124 struct autofs_sb_info {
 125         u32 magic;
 126         int pipefd;
 127         struct file *pipe;
 128         pid_t oz_pgrp;
 129         int catatonic;
 130         int version;
 131         int sub_version;
 132         int min_proto;
 133         int max_proto;
 134         unsigned long exp_timeout;
 135         unsigned int type;
 136         int reghost_enabled;
 137         int needs_reghost;
 138         struct super_block *sb;
 139         struct mutex wq_mutex;
 140         spinlock_t fs_lock;
 141         struct autofs_wait_queue *queues; /* Wait queue pointer */
 142         spinlock_t lookup_lock;
 143         struct list_head active_list;
 144         struct list_head expiring_list;
 145 };
 146
 147 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
 148 {
 149         return (struct autofs_sb_info *)(sb->s_fs_info);
 150 }
 151
 152 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
 153 {
 154         return (struct autofs_info *)(dentry->d_fsdata);
 155 }
 156
 157 /* autofs4_oz_mode(): do we see the man behind the curtain?  (The
 158    processes which do manipulations for us in user space sees the raw
 159    filesystem without "magic".) */
 160
 161 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 162         return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 163 }
 164
 165 /* Does a dentry have some pending activity? */
 166 static inline int autofs4_ispending(struct dentry *dentry)
 167 {
 168         struct autofs_info *inf = autofs4_dentry_ino(dentry);
 169
 170         if (inf->flags & AUTOFS_INF_PENDING)
 171                 return 1;
 172
 173         if (inf->flags & AUTOFS_INF_EXPIRING)
 174                 return 1;
 175
 176         return 0;
 177 }
 178
 179 static inline void autofs4_copy_atime(struct file *src, struct file *dst)
 180 {
 181         dst->f_path.dentry->d_inode->i_atime =
 182                 src->f_path.dentry->d_inode->i_atime;
 183         return;
 184 }
 185
 186 struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
 187 void autofs4_free_ino(struct autofs_info *);
 188
 189 /* Expiration */
 190 int is_autofs4_dentry(struct dentry *);
 191 int autofs4_expire_wait(struct dentry *dentry);
 192 int autofs4_expire_run(struct super_block *, struct vfsmount *,
 193                         struct autofs_sb_info *,
 194                         struct autofs_packet_expire __user *);
 195 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 196                             struct autofs_sb_info *sbi, int when);
 197 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
 198                         struct autofs_sb_info *, int __user *);
 199 struct dentry *autofs4_expire_direct(struct super_block *sb,
 200                                      struct vfsmount *mnt,
 201                                      struct autofs_sb_info *sbi, int how);
 202 struct dentry *autofs4_expire_indirect(struct super_block *sb,
 203                                        struct vfsmount *mnt,
 204                                        struct autofs_sb_info *sbi, int how);
 205
 206 /* Device node initialization */
 207
 208 int autofs_dev_ioctl_init(void);
 209 void autofs_dev_ioctl_exit(void);
 210
 211 /* Operations structures */
 212
 213 extern const struct inode_operations autofs4_symlink_inode_operations;
 214 extern const struct inode_operations autofs4_dir_inode_operations;
 215 extern const struct inode_operations autofs4_root_inode_operations;
 216 extern const struct inode_operations autofs4_indirect_root_inode_operations;
 217 extern const struct inode_operations autofs4_direct_root_inode_operations;
 218 extern const struct file_operations autofs4_dir_operations;
 219 extern const struct file_operations autofs4_root_operations;
 220
 221 /* Initializing function */
 222
 223 int autofs4_fill_super(struct super_block *, void *, int);
 224 struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
 225
 226 /* Queue management functions */
 227
 228 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 229 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 230 void autofs4_catatonic_mode(struct autofs_sb_info *);
 231
 232 static inline int autofs4_follow_mount(struct path *path)
 233 {
 234         int res = 0;
 235
 236         while (d_mountpoint(path->dentry)) {
 237                 int followed = follow_down(path);
 238                 if (!followed)
 239                         break;
 240                 res = 1;
 241         }
 242         return res;
 243 }
 244
 245 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
 246 {
 247         return new_encode_dev(sbi->sb->s_dev);
 248 }
 249
 250 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
 251 {
 252         return sbi->sb->s_root->d_inode->i_ino;
 253 }
 254
 255 static inline int simple_positive(struct dentry *dentry)
 256 {
 257         return dentry->d_inode && !d_unhashed(dentry);
 258 }
 259
 260 static inline void __autofs4_add_expiring(struct dentry *dentry)
 261 {
 262         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 263         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 264         if (ino) {
 265                 if (list_empty(&ino->expiring))
 266                         list_add(&ino->expiring, &sbi->expiring_list);
 267         }
 268         return;
 269 }
 270
 271 static inline void autofs4_add_expiring(struct dentry *dentry)
 272 {
 273         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 274         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 275         if (ino) {
 276                 spin_lock(&sbi->lookup_lock);
 277                 if (list_empty(&ino->expiring))
 278                         list_add(&ino->expiring, &sbi->expiring_list);
 279                 spin_unlock(&sbi->lookup_lock);
 280         }
 281         return;
 282 }
 283
 284 static inline void autofs4_del_expiring(struct dentry *dentry)
 285 {
 286         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 287         struct autofs_info *ino = autofs4_dentry_ino(dentry);
 288         if (ino) {
 289                 spin_lock(&sbi->lookup_lock);
 290                 if (!list_empty(&ino->expiring))
 291                         list_del_init(&ino->expiring);
 292                 spin_unlock(&sbi->lookup_lock);
 293         }
 294         return;
 295 }
 296
 297 void autofs4_dentry_release(struct dentry *);
 298 extern void autofs4_kill_sb(struct super_block *);