[net-next-2.6.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/auto_dev-ioctl.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

#define AUTOFS_DEV_IOCTL_IOC_FIRST	(AUTOFS_DEV_IOCTL_VERSION)
#define AUTOFS_DEV_IOCTL_IOC_COUNT	(AUTOFS_IOC_COUNT - 11)

#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, __func__, ##args);	\
} while (0)
#else
#define DPRINTK(fmt, args...) do {} while (0)
#endif

#define AUTOFS_WARN(fmt, args...)			\
do {							\
	printk(KERN_WARNING "pid %d: %s: " fmt "\n",	\
		current->pid, __func__, ##args);	\
} while (0)

#define AUTOFS_ERROR(fmt, args...)			\
do {							\
	printk(KERN_ERR "pid %d: %s: " fmt "\n",	\
		current->pid, __func__, ##args);	\
} while (0)

/* 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 completion expire_complete;

	struct list_head active;
	int active_count;

	struct list_head expiring;

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

	uid_t uid;
	gid_t gid;

	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 */
#define AUTOFS_INF_MOUNTPOINT	(1<<1) /* mountpoint status for direct expire */
#define AUTOFS_INF_PENDING	(1<<2) /* dentry pending mount */

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 */
	struct qstr 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;
	unsigned int wait_ctr;
};

#define AUTOFS_SBI_MAGIC 0x6d4a556d

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 */
	spinlock_t lookup_lock;
	struct list_head active_list;
	struct list_head expiring_list;
};

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 || task_pgrp_nr(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);

	if (inf->flags & AUTOFS_INF_PENDING)
		return 1;

	if (inf->flags & AUTOFS_INF_EXPIRING)
		return 1;

	return 0;
}

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_wait(struct dentry *dentry);
int autofs4_expire_run(struct super_block *, struct vfsmount *,
			struct autofs_sb_info *,
			struct autofs_packet_expire __user *);
int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
			    struct autofs_sb_info *sbi, int when);
int autofs4_expire_multi(struct super_block *, struct vfsmount *,
			struct autofs_sb_info *, int __user *);
struct dentry *autofs4_expire_direct(struct super_block *sb,
				     struct vfsmount *mnt,
				     struct autofs_sb_info *sbi, int how);
struct dentry *autofs4_expire_indirect(struct super_block *sb,
				       struct vfsmount *mnt,
				       struct autofs_sb_info *sbi, int how);

/* Device node initialization */

int autofs_dev_ioctl_init(void);
void autofs_dev_ioctl_exit(void);

/* 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 path *path)
{
	int res = 0;

	while (d_mountpoint(path->dentry)) {
		int followed = follow_down(path);
		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;
}

static inline void autofs4_add_expiring(struct dentry *dentry)
{
	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	if (ino) {
		spin_lock(&sbi->lookup_lock);
		if (list_empty(&ino->expiring))
			list_add(&ino->expiring, &sbi->expiring_list);
		spin_unlock(&sbi->lookup_lock);
	}
	return;
}

static inline void autofs4_del_expiring(struct dentry *dentry)
{
	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	if (ino) {
		spin_lock(&sbi->lookup_lock);
		if (!list_empty(&ino->expiring))
			list_del_init(&ino->expiring);
		spin_unlock(&sbi->lookup_lock);
	}
	return;
}

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>
8d7b48e0	17	#include <linux/auto_dev-ioctl.h>
1d5599e3	18	#include <linux/mutex.h>
1da177e4 LT	19	#include <linux/list.h>
	20
	21	/* This is the range of ioctl() numbers we claim as ours */
	22	#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
	23	#define AUTOFS_IOC_COUNT 32
	24
8d7b48e0 IK	25	#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
	26	#define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)
	27
1da177e4 LT	28	#include <linux/kernel.h>
	29	#include <linux/slab.h>
	30	#include <linux/time.h>
	31	#include <linux/string.h>
	32	#include <linux/wait.h>
	33	#include <linux/sched.h>
	34	#include <linux/mount.h>
	35	#include <linux/namei.h>
	36	#include <asm/current.h>
	37	#include <asm/uaccess.h>
	38
	39	/* #define DEBUG */
	40
	41	#ifdef DEBUG
8d7b48e0 IK	42	#define DPRINTK(fmt, args...) \
	43	do { \
	44	printk(KERN_DEBUG "pid %d: %s: " fmt "\n", \
	45	current->pid, __func__, ##args); \
	46	} while (0)
1da177e4	47	#else
8d7b48e0	48	#define DPRINTK(fmt, args...) do {} while (0)
1da177e4 LT	49	#endif
1da177e4 LT	50
8d7b48e0 IK	51	#define AUTOFS_WARN(fmt, args...) \
	52	do { \
	53	printk(KERN_WARNING "pid %d: %s: " fmt "\n", \
	54	current->pid, __func__, ##args); \
	55	} while (0)
	56
	57	#define AUTOFS_ERROR(fmt, args...) \
	58	do { \
	59	printk(KERN_ERR "pid %d: %s: " fmt "\n", \
	60	current->pid, __func__, ##args); \
	61	} while (0)
	62
1da177e4 LT	63	/* Unified info structure. This is pointed to by both the dentry and
	64	inode structures. Each file in the filesystem has an instance of this
	65	structure. It holds a reference to the dentry, so dentries are never
	66	flushed while the file exists. All name lookups are dealt with at the
	67	dentry level, although the filesystem can interfere in the validation
	68	process. Readdir is implemented by traversing the dentry lists. */
	69	struct autofs_info {
	70	struct dentry *dentry;
	71	struct inode *inode;
	72
	73	int flags;
	74
6e60a9ab IK	75	struct completion expire_complete;
6e60a9ab IK	76
25767378	77	struct list_head active;
4f8427d1 IK	78	int active_count;
4f8427d1 IK	79
5f6f4f28	80	struct list_head expiring;
f50b6f86	81
1da177e4 LT	82	struct autofs_sb_info *sbi;
1da177e4 LT	83	unsigned long last_used;
1aff3c8b	84	atomic_t count;
1da177e4	85
c0f54d3e IK	86	uid_t uid;
	87	gid_t gid;
	88
1da177e4 LT	89	mode_t mode;
	90	size_t size;
	91
	92	void (free)(struct autofs_info );
	93	union {
	94	const char *symlink;
	95	} u;
	96	};
	97
	98	#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
6e60a9ab	99	#define AUTOFS_INF_MOUNTPOINT (1<<1) /* mountpoint status for direct expire */
aa952eb2	100	#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
1da177e4 LT	101
	102	struct autofs_wait_queue {
	103	wait_queue_head_t queue;
	104	struct autofs_wait_queue *next;
	105	autofs_wqt_t wait_queue_token;
	106	/* We use the following to see what we are waiting for */
70b52a0a	107	struct qstr name;
5c0a32fc IK	108	u32 dev;
	109	u64 ino;
	110	uid_t uid;
	111	gid_t gid;
	112	pid_t pid;
	113	pid_t tgid;
1da177e4 LT	114	/* This is for status reporting upon return */
1da177e4 LT	115	int status;
296f7bf7	116	unsigned int wait_ctr;
1da177e4 LT	117	};
	118
	119	#define AUTOFS_SBI_MAGIC 0x6d4a556d
	120
	121	struct autofs_sb_info {
	122	u32 magic;
d7c4a5f1	123	int pipefd;
1da177e4 LT	124	struct file *pipe;
	125	pid_t oz_pgrp;
	126	int catatonic;
	127	int version;
	128	int sub_version;
d7c4a5f1 IK	129	int min_proto;
d7c4a5f1 IK	130	int max_proto;
1da177e4	131	unsigned long exp_timeout;
34ca959c	132	unsigned int type;
1da177e4 LT	133	int reghost_enabled;
	134	int needs_reghost;
	135	struct super_block *sb;
1d5599e3	136	struct mutex wq_mutex;
3a9720ce	137	spinlock_t fs_lock;
1da177e4	138	struct autofs_wait_queue queues; / Wait queue pointer */
5f6f4f28	139	spinlock_t lookup_lock;
25767378	140	struct list_head active_list;
5f6f4f28	141	struct list_head expiring_list;
1da177e4 LT	142	};
	143
	144	static inline struct autofs_sb_info autofs4_sbi(struct super_block sb)
	145	{
	146	return (struct autofs_sb_info *)(sb->s_fs_info);
	147	}
	148
	149	static inline struct autofs_info autofs4_dentry_ino(struct dentry dentry)
	150	{
	151	return (struct autofs_info *)(dentry->d_fsdata);
	152	}
	153
	154	/* autofs4_oz_mode(): do we see the man behind the curtain? (The
	155	processes which do manipulations for us in user space sees the raw
	156	filesystem without "magic".) */
	157
	158	static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
a47afb0f	159	return sbi->catatonic \|\| task_pgrp_nr(current) == sbi->oz_pgrp;
1da177e4 LT	160	}
	161
	162	/* Does a dentry have some pending activity? */
	163	static inline int autofs4_ispending(struct dentry *dentry)
	164	{
	165	struct autofs_info *inf = autofs4_dentry_ino(dentry);
	166
aa952eb2	167	if (inf->flags & AUTOFS_INF_PENDING)
3a9720ce IK	168	return 1;
3a9720ce IK	169
97e7449a IK	170	if (inf->flags & AUTOFS_INF_EXPIRING)
97e7449a IK	171	return 1;
3a9720ce	172
97e7449a	173	return 0;
1da177e4 LT	174	}
	175
	176	static inline void autofs4_copy_atime(struct file src, struct file dst)
	177	{
a4669ed8 JJS	178	dst->f_path.dentry->d_inode->i_atime =
a4669ed8 JJS	179	src->f_path.dentry->d_inode->i_atime;
1da177e4 LT	180	return;
	181	}
	182
	183	struct inode autofs4_get_inode(struct super_block , struct autofs_info *);
	184	void autofs4_free_ino(struct autofs_info *);
	185
	186	/* Expiration */
	187	int is_autofs4_dentry(struct dentry *);
06a35985	188	int autofs4_expire_wait(struct dentry *dentry);
1da177e4 LT	189	int autofs4_expire_run(struct super_block , struct vfsmount ,
	190	struct autofs_sb_info *,
	191	struct autofs_packet_expire __user *);
56fcef75 IK	192	int autofs4_do_expire_multi(struct super_block sb, struct vfsmount mnt,
56fcef75 IK	193	struct autofs_sb_info *sbi, int when);
1da177e4 LT	194	int autofs4_expire_multi(struct super_block , struct vfsmount ,
1da177e4 LT	195	struct autofs_sb_info , int __user );
8d7b48e0 IK	196	struct dentry autofs4_expire_direct(struct super_block sb,
	197	struct vfsmount *mnt,
	198	struct autofs_sb_info *sbi, int how);
	199	struct dentry autofs4_expire_indirect(struct super_block sb,
	200	struct vfsmount *mnt,
	201	struct autofs_sb_info *sbi, int how);
	202
	203	/* Device node initialization */
	204
	205	int autofs_dev_ioctl_init(void);
	206	void autofs_dev_ioctl_exit(void);
1da177e4 LT	207
	208	/* Operations structures */
	209
754661f1 AV	210	extern const struct inode_operations autofs4_symlink_inode_operations;
	211	extern const struct inode_operations autofs4_dir_inode_operations;
	212	extern const struct inode_operations autofs4_root_inode_operations;
	213	extern const struct inode_operations autofs4_indirect_root_inode_operations;
	214	extern const struct inode_operations autofs4_direct_root_inode_operations;
4b6f5d20 AV	215	extern const struct file_operations autofs4_dir_operations;
4b6f5d20 AV	216	extern const struct file_operations autofs4_root_operations;
1da177e4 LT	217
	218	/* Initializing function */
	219
	220	int autofs4_fill_super(struct super_block , void , int);
	221	struct autofs_info autofs4_init_ino(struct autofs_info , struct autofs_sb_info *sbi, mode_t mode);
	222
	223	/* Queue management functions */
	224
1da177e4 LT	225	int autofs4_wait(struct autofs_sb_info ,struct dentry , enum autofs_notify);
	226	int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
	227	void autofs4_catatonic_mode(struct autofs_sb_info *);
	228
9393bd07	229	static inline int autofs4_follow_mount(struct path *path)
9b1e3afd IK	230	{
	231	int res = 0;
	232
9393bd07 AV	233	while (d_mountpoint(path->dentry)) {
9393bd07 AV	234	int followed = follow_down(path);
9b1e3afd IK	235	if (!followed)
	236	break;
	237	res = 1;
	238	}
	239	return res;
	240	}
	241
5c0a32fc IK	242	static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
	243	{
	244	return new_encode_dev(sbi->sb->s_dev);
	245	}
	246
	247	static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
	248	{
	249	return sbi->sb->s_root->d_inode->i_ino;
	250	}
	251
1da177e4 LT	252	static inline int simple_positive(struct dentry *dentry)
	253	{
	254	return dentry->d_inode && !d_unhashed(dentry);
	255	}
	256
90a59c7c	257	static inline int __simple_empty(struct dentry *dentry)
1da177e4 LT	258	{
	259	struct dentry *child;
	260	int ret = 0;
	261
5160ee6f	262	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
1da177e4 LT	263	if (simple_positive(child))
	264	goto out;
	265	ret = 1;
	266	out:
	267	return ret;
	268	}
f5b95ff0	269
c4cd70b3 IK	270	static inline void autofs4_add_expiring(struct dentry *dentry)
	271	{
	272	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	273	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	274	if (ino) {
	275	spin_lock(&sbi->lookup_lock);
	276	if (list_empty(&ino->expiring))
	277	list_add(&ino->expiring, &sbi->expiring_list);
	278	spin_unlock(&sbi->lookup_lock);
	279	}
	280	return;
	281	}
	282
	283	static inline void autofs4_del_expiring(struct dentry *dentry)
	284	{
	285	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	286	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	287	if (ino) {
	288	spin_lock(&sbi->lookup_lock);
	289	if (!list_empty(&ino->expiring))
	290	list_del_init(&ino->expiring);
	291	spin_unlock(&sbi->lookup_lock);
	292	}
	293	return;
	294	}
	295
f5b95ff0	296	void autofs4_dentry_release(struct dentry *);
6ce31523	297	extern void autofs4_kill_sb(struct super_block *);