[linux-2.6-block.git] / fs / autofs4 / autofs_i.h

/* -*- c -*- ------------------------------------------------------------- *
 *   
 * linux/fs/autofs/autofs_i.h
 *
 *   Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
 *   Copyright 2005-2006 Ian Kent <raven@themaw.net>
 *
 * This file is part of the Linux kernel and is made available under
 * the terms of the GNU General Public License, version 2, or at your
 * option, any later version, incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/* Internal header file for autofs */

#include <linux/auto_fs4.h>
#include <linux/mutex.h>
#include <linux/list.h>

/* This is the range of ioctl() numbers we claim as ours */
#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
#define AUTOFS_IOC_COUNT     32

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/string.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <asm/current.h>
#include <asm/uaccess.h>

/* #define DEBUG */

#ifdef DEBUG
#define DPRINTK(fmt,args...) do { printk(KERN_DEBUG "pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); } while(0)
#else
#define DPRINTK(fmt,args...) do {} while(0)
#endif

/* Unified info structure.  This is pointed to by both the dentry and
   inode structures.  Each file in the filesystem has an instance of this
   structure.  It holds a reference to the dentry, so dentries are never
   flushed while the file exists.  All name lookups are dealt with at the
   dentry level, although the filesystem can interfere in the validation
   process.  Readdir is implemented by traversing the dentry lists. */
struct autofs_info {
	struct dentry	*dentry;
	struct inode	*inode;

	int		flags;

	struct autofs_sb_info *sbi;
	unsigned long last_used;
	atomic_t count;

	mode_t	mode;
	size_t	size;

	void (*free)(struct autofs_info *);
	union {
		const char *symlink;
	} u;
};

#define AUTOFS_INF_EXPIRING	(1<<0) /* dentry is in the process of expiring */

struct autofs_wait_queue {
	wait_queue_head_t queue;
	struct autofs_wait_queue *next;
	autofs_wqt_t wait_queue_token;
	/* We use the following to see what we are waiting for */
	unsigned int hash;
	unsigned int len;
	char *name;
	u32 dev;
	u64 ino;
	uid_t uid;
	gid_t gid;
	pid_t pid;
	pid_t tgid;
	/* This is for status reporting upon return */
	int status;
	atomic_t wait_ctr;
};

#define AUTOFS_SBI_MAGIC 0x6d4a556d

#define AUTOFS_TYPE_INDIRECT     0x0001
#define AUTOFS_TYPE_DIRECT       0x0002
#define AUTOFS_TYPE_OFFSET       0x0004

struct autofs_sb_info {
	u32 magic;
	int pipefd;
	struct file *pipe;
	pid_t oz_pgrp;
	int catatonic;
	int version;
	int sub_version;
	int min_proto;
	int max_proto;
	unsigned long exp_timeout;
	unsigned int type;
	int reghost_enabled;
	int needs_reghost;
	struct super_block *sb;
	struct mutex wq_mutex;
	spinlock_t fs_lock;
	struct autofs_wait_queue *queues; /* Wait queue pointer */
};

static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
{
	return (struct autofs_sb_info *)(sb->s_fs_info);
}

static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
{
	return (struct autofs_info *)(dentry->d_fsdata);
}

/* autofs4_oz_mode(): do we see the man behind the curtain?  (The
   processes which do manipulations for us in user space sees the raw
   filesystem without "magic".) */

static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
	return sbi->catatonic || process_group(current) == sbi->oz_pgrp;
}

/* Does a dentry have some pending activity? */
static inline int autofs4_ispending(struct dentry *dentry)
{
	struct autofs_info *inf = autofs4_dentry_ino(dentry);
	int pending = 0;

	if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
		return 1;

	if (inf) {
		spin_lock(&inf->sbi->fs_lock);
		pending = inf->flags & AUTOFS_INF_EXPIRING;
		spin_unlock(&inf->sbi->fs_lock);
	}

	return pending;
}

static inline void autofs4_copy_atime(struct file *src, struct file *dst)
{
	dst->f_path.dentry->d_inode->i_atime =
		src->f_path.dentry->d_inode->i_atime;
	return;
}

struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
void autofs4_free_ino(struct autofs_info *);

/* Expiration */
int is_autofs4_dentry(struct dentry *);
int autofs4_expire_run(struct super_block *, struct vfsmount *,
			struct autofs_sb_info *,
			struct autofs_packet_expire __user *);
int autofs4_expire_multi(struct super_block *, struct vfsmount *,
			struct autofs_sb_info *, int __user *);

/* Operations structures */

extern const struct inode_operations autofs4_symlink_inode_operations;
extern const struct inode_operations autofs4_dir_inode_operations;
extern const struct inode_operations autofs4_root_inode_operations;
extern const struct inode_operations autofs4_indirect_root_inode_operations;
extern const struct inode_operations autofs4_direct_root_inode_operations;
extern const struct file_operations autofs4_dir_operations;
extern const struct file_operations autofs4_root_operations;

/* Initializing function */

int autofs4_fill_super(struct super_block *, void *, int);
struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);

/* Queue management functions */

int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
void autofs4_catatonic_mode(struct autofs_sb_info *);

static inline int autofs4_follow_mount(struct vfsmount **mnt, struct dentry **dentry)
{
	int res = 0;

	while (d_mountpoint(*dentry)) {
		int followed = follow_down(mnt, dentry);
		if (!followed)
			break;
		res = 1;
	}
	return res;
}

static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
{
	return new_encode_dev(sbi->sb->s_dev);
}

static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
{
	return sbi->sb->s_root->d_inode->i_ino;
}

static inline int simple_positive(struct dentry *dentry)
{
	return dentry->d_inode && !d_unhashed(dentry);
}

static inline int __simple_empty(struct dentry *dentry)
{
	struct dentry *child;
	int ret = 0;

	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
		if (simple_positive(child))
			goto out;
	ret = 1;
out:
	return ret;
}

void autofs4_dentry_release(struct dentry *);
extern void autofs4_kill_sb(struct super_block *);
Commit	Line	Data
1da177e4 LT	1	/* -- c -- ------------------------------------------------------------- *
	2	*
	3	* linux/fs/autofs/autofs_i.h
	4	*
	5	* Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
34ca959c	6	* Copyright 2005-2006 Ian Kent <raven@themaw.net>
1da177e4 LT	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>
1d5599e3	17	#include <linux/mutex.h>
1da177e4 LT	18	#include <linux/list.h>
	19
	20	/* This is the range of ioctl() numbers we claim as ours */
	21	#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
	22	#define AUTOFS_IOC_COUNT 32
	23
	24	#include <linux/kernel.h>
	25	#include <linux/slab.h>
	26	#include <linux/time.h>
	27	#include <linux/string.h>
	28	#include <linux/wait.h>
	29	#include <linux/sched.h>
	30	#include <linux/mount.h>
	31	#include <linux/namei.h>
	32	#include <asm/current.h>
	33	#include <asm/uaccess.h>
	34
	35	/* #define DEBUG */
	36
	37	#ifdef DEBUG
	38	#define DPRINTK(fmt,args...) do { printk(KERN_DEBUG "pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); } while(0)
	39	#else
	40	#define DPRINTK(fmt,args...) do {} while(0)
	41	#endif
	42
1da177e4 LT	43	/* Unified info structure. This is pointed to by both the dentry and
	44	inode structures. Each file in the filesystem has an instance of this
	45	structure. It holds a reference to the dentry, so dentries are never
	46	flushed while the file exists. All name lookups are dealt with at the
	47	dentry level, although the filesystem can interfere in the validation
	48	process. Readdir is implemented by traversing the dentry lists. */
	49	struct autofs_info {
	50	struct dentry *dentry;
	51	struct inode *inode;
	52
	53	int flags;
	54
	55	struct autofs_sb_info *sbi;
	56	unsigned long last_used;
1aff3c8b	57	atomic_t count;
1da177e4 LT	58
	59	mode_t mode;
	60	size_t size;
	61
	62	void (free)(struct autofs_info );
	63	union {
	64	const char *symlink;
	65	} u;
	66	};
	67
	68	#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
	69
	70	struct autofs_wait_queue {
	71	wait_queue_head_t queue;
	72	struct autofs_wait_queue *next;
	73	autofs_wqt_t wait_queue_token;
	74	/* We use the following to see what we are waiting for */
a5370553 IK	75	unsigned int hash;
a5370553 IK	76	unsigned int len;
1da177e4	77	char *name;
5c0a32fc IK	78	u32 dev;
	79	u64 ino;
	80	uid_t uid;
	81	gid_t gid;
	82	pid_t pid;
	83	pid_t tgid;
1da177e4 LT	84	/* This is for status reporting upon return */
	85	int status;
	86	atomic_t wait_ctr;
	87	};
	88
	89	#define AUTOFS_SBI_MAGIC 0x6d4a556d
	90
44d53eb0 IK	91	#define AUTOFS_TYPE_INDIRECT 0x0001
	92	#define AUTOFS_TYPE_DIRECT 0x0002
	93	#define AUTOFS_TYPE_OFFSET 0x0004
34ca959c	94
1da177e4 LT	95	struct autofs_sb_info {
1da177e4 LT	96	u32 magic;
d7c4a5f1	97	int pipefd;
1da177e4 LT	98	struct file *pipe;
	99	pid_t oz_pgrp;
	100	int catatonic;
	101	int version;
	102	int sub_version;
d7c4a5f1 IK	103	int min_proto;
d7c4a5f1 IK	104	int max_proto;
1da177e4	105	unsigned long exp_timeout;
34ca959c	106	unsigned int type;
1da177e4 LT	107	int reghost_enabled;
	108	int needs_reghost;
	109	struct super_block *sb;
1d5599e3	110	struct mutex wq_mutex;
3a9720ce	111	spinlock_t fs_lock;
1da177e4 LT	112	struct autofs_wait_queue queues; / Wait queue pointer */
	113	};
	114
	115	static inline struct autofs_sb_info autofs4_sbi(struct super_block sb)
	116	{
	117	return (struct autofs_sb_info *)(sb->s_fs_info);
	118	}
	119
	120	static inline struct autofs_info autofs4_dentry_ino(struct dentry dentry)
	121	{
	122	return (struct autofs_info *)(dentry->d_fsdata);
	123	}
	124
	125	/* autofs4_oz_mode(): do we see the man behind the curtain? (The
	126	processes which do manipulations for us in user space sees the raw
	127	filesystem without "magic".) */
	128
	129	static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
	130	return sbi->catatonic \|\| process_group(current) == sbi->oz_pgrp;
	131	}
	132
	133	/* Does a dentry have some pending activity? */
	134	static inline int autofs4_ispending(struct dentry *dentry)
	135	{
	136	struct autofs_info *inf = autofs4_dentry_ino(dentry);
3a9720ce	137	int pending = 0;
1da177e4	138
3a9720ce IK	139	if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
	140	return 1;
	141
	142	if (inf) {
	143	spin_lock(&inf->sbi->fs_lock);
	144	pending = inf->flags & AUTOFS_INF_EXPIRING;
	145	spin_unlock(&inf->sbi->fs_lock);
	146	}
	147
	148	return pending;
1da177e4 LT	149	}
	150
	151	static inline void autofs4_copy_atime(struct file src, struct file dst)
	152	{
a4669ed8 JJS	153	dst->f_path.dentry->d_inode->i_atime =
a4669ed8 JJS	154	src->f_path.dentry->d_inode->i_atime;
1da177e4 LT	155	return;
	156	}
	157
	158	struct inode autofs4_get_inode(struct super_block , struct autofs_info *);
	159	void autofs4_free_ino(struct autofs_info *);
	160
	161	/* Expiration */
	162	int is_autofs4_dentry(struct dentry *);
	163	int autofs4_expire_run(struct super_block , struct vfsmount ,
	164	struct autofs_sb_info *,
	165	struct autofs_packet_expire __user *);
	166	int autofs4_expire_multi(struct super_block , struct vfsmount ,
	167	struct autofs_sb_info , int __user );
	168
	169	/* Operations structures */
	170
754661f1 AV	171	extern const struct inode_operations autofs4_symlink_inode_operations;
	172	extern const struct inode_operations autofs4_dir_inode_operations;
	173	extern const struct inode_operations autofs4_root_inode_operations;
	174	extern const struct inode_operations autofs4_indirect_root_inode_operations;
	175	extern const struct inode_operations autofs4_direct_root_inode_operations;
4b6f5d20 AV	176	extern const struct file_operations autofs4_dir_operations;
4b6f5d20 AV	177	extern const struct file_operations autofs4_root_operations;
1da177e4 LT	178
	179	/* Initializing function */
	180
	181	int autofs4_fill_super(struct super_block , void , int);
	182	struct autofs_info autofs4_init_ino(struct autofs_info , struct autofs_sb_info *sbi, mode_t mode);
	183
	184	/* Queue management functions */
	185
1da177e4 LT	186	int autofs4_wait(struct autofs_sb_info ,struct dentry , enum autofs_notify);
	187	int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
	188	void autofs4_catatonic_mode(struct autofs_sb_info *);
	189
9b1e3afd IK	190	static inline int autofs4_follow_mount(struct vfsmount mnt, struct dentry dentry)
	191	{
	192	int res = 0;
	193
	194	while (d_mountpoint(*dentry)) {
	195	int followed = follow_down(mnt, dentry);
	196	if (!followed)
	197	break;
	198	res = 1;
	199	}
	200	return res;
	201	}
	202
5c0a32fc IK	203	static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
	204	{
	205	return new_encode_dev(sbi->sb->s_dev);
	206	}
	207
	208	static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
	209	{
	210	return sbi->sb->s_root->d_inode->i_ino;
	211	}
	212
1da177e4 LT	213	static inline int simple_positive(struct dentry *dentry)
	214	{
	215	return dentry->d_inode && !d_unhashed(dentry);
	216	}
	217
90a59c7c	218	static inline int __simple_empty(struct dentry *dentry)
1da177e4 LT	219	{
	220	struct dentry *child;
	221	int ret = 0;
	222
5160ee6f	223	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
1da177e4 LT	224	if (simple_positive(child))
	225	goto out;
	226	ret = 1;
	227	out:
	228	return ret;
	229	}
f5b95ff0 AB	230
f5b95ff0 AB	231	void autofs4_dentry_release(struct dentry *);
6ce31523	232	extern void autofs4_kill_sb(struct super_block *);