| 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 | 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_nr(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 *); |