1 /* -*- linux-c -*- ------------------------------------------------------- * 2 * 3 * linux/fs/autofs/autofs_i.h 4 * 5 * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved 6 * 7 * This file is part of the Linux kernel and is made available under 8 * the terms of the GNU General Public License, version 2, or at your 9 * option, any later version, incorporated herein by reference. 10 * 11 * ----------------------------------------------------------------------- */ 12 13 /* Internal header file for autofs */ 14 15 #include <linux/auto_fs.h> 16 17 /* This is the range of ioctl() numbers we claim as ours */ 18 #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY 19 #define AUTOFS_IOC_COUNT 32 20 21 #include <linux/kernel.h> 22 #include <linux/slab.h> 23 #include <linux/time.h> 24 #include <linux/string.h> 25 #include <linux/wait.h> 26 #include <linux/dcache.h> 27 #include <linux/namei.h> 28 #include <linux/mount.h> 29 #include <linux/sched.h> 30 31 #include <asm/current.h> 32 #include <asm/uaccess.h> 33 34 #ifdef DEBUG 35 #define DPRINTK(D) (printk D) 36 #else 37 #define DPRINTK(D) ((void)0) 38 #endif 39 40 /* 41 * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the 42 * kernel will keep the negative response cached for up to the time given 43 * here, although the time can be shorter if the kernel throws the dcache 44 * entry away. This probably should be settable from user space. 45 */ 46 #define AUTOFS_NEGATIVE_TIMEOUT (60*HZ) /* 1 minute */ 47 48 /* Structures associated with the root directory hash table */ 49 50 #define AUTOFS_HASH_SIZE 67 51 52 struct autofs_dir_ent { 53 int hash; 54 char *name; 55 int len; 56 ino_t ino; 57 struct dentry *dentry; 58 /* Linked list of entries */ 59 struct autofs_dir_ent *next; 60 struct autofs_dir_ent **back; 61 /* The following entries are for the expiry system */ 62 unsigned long last_usage; 63 struct list_head exp; 64 }; 65 66 struct autofs_dirhash { 67 struct autofs_dir_ent *h[AUTOFS_HASH_SIZE]; 68 struct list_head expiry_head; 69 }; 70 71 struct autofs_wait_queue { 72 wait_queue_head_t queue; 73 struct autofs_wait_queue *next; 74 autofs_wqt_t wait_queue_token; 75 /* We use the following to see what we are waiting for */ 76 int hash; 77 int len; 78 char *name; 79 /* This is for status reporting upon return */ 80 int status; 81 int wait_ctr; 82 }; 83 84 struct autofs_symlink { 85 char *data; 86 int len; 87 time_t mtime; 88 }; 89 90 #define AUTOFS_MAX_SYMLINKS 256 91 92 #define AUTOFS_ROOT_INO 1 93 #define AUTOFS_FIRST_SYMLINK 2 94 #define AUTOFS_FIRST_DIR_INO (AUTOFS_FIRST_SYMLINK+AUTOFS_MAX_SYMLINKS) 95 96 #define AUTOFS_SYMLINK_BITMAP_LEN \ 97 ((AUTOFS_MAX_SYMLINKS+((sizeof(long)*1)-1))/(sizeof(long)*8)) 98 99 #define AUTOFS_SBI_MAGIC 0x6d4a556d 100 101 struct autofs_sb_info { 102 u32 magic; 103 struct file *pipe; 104 struct pid *oz_pgrp; 105 int catatonic; 106 struct super_block *sb; 107 unsigned long exp_timeout; 108 ino_t next_dir_ino; 109 struct autofs_wait_queue *queues; /* Wait queue pointer */ 110 struct autofs_dirhash dirhash; /* Root directory hash */ 111 struct autofs_symlink symlink[AUTOFS_MAX_SYMLINKS]; 112 unsigned long symlink_bitmap[AUTOFS_SYMLINK_BITMAP_LEN]; 113 }; 114 115 static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb) 116 { 117 return (struct autofs_sb_info *)(sb->s_fs_info); 118 } 119 120 /* autofs_oz_mode(): do we see the man behind the curtain? (The 121 processes which do manipulations for us in user space sees the raw 122 filesystem without "magic".) */ 123 124 static inline int autofs_oz_mode(struct autofs_sb_info *sbi) { 125 return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp; 126 } 127 128 /* Hash operations */ 129 130 void autofs_initialize_hash(struct autofs_dirhash *); 131 struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *); 132 void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *); 133 void autofs_hash_delete(struct autofs_dir_ent *); 134 struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *); 135 void autofs_hash_dputall(struct autofs_dirhash *); 136 void autofs_hash_nuke(struct autofs_sb_info *); 137 138 /* Expiration-handling functions */ 139 140 void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *); 141 struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt); 142 143 /* Operations structures */ 144 145 extern const struct inode_operations autofs_root_inode_operations; 146 extern const struct inode_operations autofs_symlink_inode_operations; 147 extern const struct file_operations autofs_root_operations; 148 149 /* Initializing function */ 150 151 int autofs_fill_super(struct super_block *, void *, int); 152 void autofs_kill_sb(struct super_block *sb); 153 154 /* Queue management functions */ 155 156 int autofs_wait(struct autofs_sb_info *,struct qstr *); 157 int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int); 158 void autofs_catatonic_mode(struct autofs_sb_info *); 159 160 #ifdef DEBUG 161 void autofs_say(const char *name, int len); 162 #else 163 #define autofs_say(n,l) ((void)0) 164 #endif 165