[deliverable/linux.git] / include / linux / mount.h

/*
 *
 * Definitions for mount interface. This describes the in the kernel build 
 * linkedlist with mounted filesystems.
 *
 * Author:  Marco van Wieringen <mvw@planets.elm.net>
 *
 */
#ifndef _LINUX_MOUNT_H
#define _LINUX_MOUNT_H

#include <linux/types.h>
#include <linux/list.h>
#include <linux/nodemask.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>

struct super_block;
struct vfsmount;
struct dentry;
struct mnt_namespace;

#define MNT_NOSUID	0x01
#define MNT_NODEV	0x02
#define MNT_NOEXEC	0x04
#define MNT_NOATIME	0x08
#define MNT_NODIRATIME	0x10
#define MNT_RELATIME	0x20
#define MNT_READONLY	0x40	/* does the user want this to be r/o? */

#define MNT_SHRINKABLE	0x100
#define MNT_IMBALANCED_WRITE_COUNT	0x200 /* just for debugging */

#define MNT_SHARED	0x1000	/* if the vfsmount is a shared mount */
#define MNT_UNBINDABLE	0x2000	/* if the vfsmount is a unbindable mount */
#define MNT_PNODE_MASK	0x3000	/* propagation flag mask */

struct vfsmount {
	struct list_head mnt_hash;
	struct vfsmount *mnt_parent;	/* fs we are mounted on */
	struct dentry *mnt_mountpoint;	/* dentry of mountpoint */
	struct dentry *mnt_root;	/* root of the mounted tree */
	struct super_block *mnt_sb;	/* pointer to superblock */
	struct list_head mnt_mounts;	/* list of children, anchored here */
	struct list_head mnt_child;	/* and going through their mnt_child */
	int mnt_flags;
	/* 4 bytes hole on 64bits arches */
	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
	struct list_head mnt_list;
	struct list_head mnt_expire;	/* link in fs-specific expiry list */
	struct list_head mnt_share;	/* circular list of shared mounts */
	struct list_head mnt_slave_list;/* list of slave mounts */
	struct list_head mnt_slave;	/* slave list entry */
	struct vfsmount *mnt_master;	/* slave is on master->mnt_slave_list */
	struct mnt_namespace *mnt_ns;	/* containing namespace */
	int mnt_id;			/* mount identifier */
	int mnt_group_id;		/* peer group identifier */
	/*
	 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
	 * to let these frequently modified fields in a separate cache line
	 * (so that reads of mnt_flags wont ping-pong on SMP machines)
	 */
	atomic_t mnt_count;
	int mnt_expiry_mark;		/* true if marked for expiry */
	int mnt_pinned;
	int mnt_ghosts;
	/*
	 * This value is not stable unless all of the mnt_writers[] spinlocks
	 * are held, and all mnt_writer[]s on this mount have 0 as their ->count
	 */
	atomic_t __mnt_writers;
};

static inline struct vfsmount *mntget(struct vfsmount *mnt)
{
	if (mnt)
		atomic_inc(&mnt->mnt_count);
	return mnt;
}

extern int mnt_want_write(struct vfsmount *mnt);
extern void mnt_drop_write(struct vfsmount *mnt);
extern void mntput_no_expire(struct vfsmount *mnt);
extern void mnt_pin(struct vfsmount *mnt);
extern void mnt_unpin(struct vfsmount *mnt);
extern int __mnt_is_readonly(struct vfsmount *mnt);

static inline void mntput(struct vfsmount *mnt)
{
	if (mnt) {
		mnt->mnt_expiry_mark = 0;
		mntput_no_expire(mnt);
	}
}

extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
				      const char *name, void *data);

struct file_system_type;
extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
				      int flags, const char *name,
				      void *data);

struct nameidata;

struct path;
extern int do_add_mount(struct vfsmount *newmnt, struct path *path,
			int mnt_flags, struct list_head *fslist);

extern void mark_mounts_for_expiry(struct list_head *mounts);

extern spinlock_t vfsmount_lock;
extern dev_t name_to_dev_t(char *name);

#endif /* _LINUX_MOUNT_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	*
	3	* Definitions for mount interface. This describes the in the kernel build
	4	* linkedlist with mounted filesystems.
	5	*
	6	* Author: Marco van Wieringen <mvw@planets.elm.net>
	7	*
1da177e4 LT	8	*/
	9	#ifndef _LINUX_MOUNT_H
	10	#define _LINUX_MOUNT_H
1da177e4	11
d53d9f16	12	#include <linux/types.h>
1da177e4	13	#include <linux/list.h>
3d733633	14	#include <linux/nodemask.h>
1da177e4 LT	15	#include <linux/spinlock.h>
	16	#include <asm/atomic.h>
	17
726c3342 DH	18	struct super_block;
	19	struct vfsmount;
	20	struct dentry;
6b3286ed	21	struct mnt_namespace;
726c3342	22
07b20889 RP	23	#define MNT_NOSUID 0x01
	24	#define MNT_NODEV 0x02
	25	#define MNT_NOEXEC 0x04
fc33a7bb CH	26	#define MNT_NOATIME 0x08
fc33a7bb CH	27	#define MNT_NODIRATIME 0x10
47ae32d6	28	#define MNT_RELATIME 0x20
2e4b7fcd	29	#define MNT_READONLY 0x40 /* does the user want this to be r/o? */
bf066c7d	30
5528f911	31	#define MNT_SHRINKABLE 0x100
3d733633	32	#define MNT_IMBALANCED_WRITE_COUNT 0x200 /* just for debugging */
5528f911	33
fc33a7bb CH	34	#define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
fc33a7bb CH	35	#define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
beb7dd86	36	#define MNT_PNODE_MASK 0x3000 /* propagation flag mask */
1da177e4	37
07b20889	38	struct vfsmount {
1da177e4 LT	39	struct list_head mnt_hash;
	40	struct vfsmount mnt_parent; / fs we are mounted on */
	41	struct dentry mnt_mountpoint; / dentry of mountpoint */
	42	struct dentry mnt_root; / root of the mounted tree */
	43	struct super_block mnt_sb; / pointer to superblock */
	44	struct list_head mnt_mounts; /* list of children, anchored here */
	45	struct list_head mnt_child; /* and going through their mnt_child */
1da177e4	46	int mnt_flags;
4ba4d4c0	47	/* 4 bytes hole on 64bits arches */
88b38782	48	const char mnt_devname; / Name of device e.g. /dev/dsk/hda1 */
1da177e4	49	struct list_head mnt_list;
55e700b9	50	struct list_head mnt_expire; /* link in fs-specific expiry list */
03e06e68	51	struct list_head mnt_share; /* circular list of shared mounts */
a58b0eb8 RP	52	struct list_head mnt_slave_list;/* list of slave mounts */
	53	struct list_head mnt_slave; /* slave list entry */
	54	struct vfsmount mnt_master; / slave is on master->mnt_slave_list */
6b3286ed	55	struct mnt_namespace mnt_ns; / containing namespace */
73cd49ec	56	int mnt_id; /* mount identifier */
719f5d7f	57	int mnt_group_id; /* peer group identifier */
4ba4d4c0 ED	58	/*
	59	* We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
	60	* to let these frequently modified fields in a separate cache line
	61	* (so that reads of mnt_flags wont ping-pong on SMP machines)
	62	*/
	63	atomic_t mnt_count;
	64	int mnt_expiry_mark; /* true if marked for expiry */
7b7b1ace	65	int mnt_pinned;
7c4b93d8	66	int mnt_ghosts;
3d733633 DH	67	/*
	68	* This value is not stable unless all of the mnt_writers[] spinlocks
	69	* are held, and all mnt_writer[]s on this mount have 0 as their ->count
	70	*/
	71	atomic_t __mnt_writers;
1da177e4 LT	72	};
	73
	74	static inline struct vfsmount mntget(struct vfsmount mnt)
	75	{
	76	if (mnt)
	77	atomic_inc(&mnt->mnt_count);
	78	return mnt;
	79	}
	80
8366025e DH	81	extern int mnt_want_write(struct vfsmount *mnt);
8366025e DH	82	extern void mnt_drop_write(struct vfsmount *mnt);
7b7b1ace AV	83	extern void mntput_no_expire(struct vfsmount *mnt);
	84	extern void mnt_pin(struct vfsmount *mnt);
	85	extern void mnt_unpin(struct vfsmount *mnt);
8366025e	86	extern int __mnt_is_readonly(struct vfsmount *mnt);
1da177e4 LT	87
	88	static inline void mntput(struct vfsmount *mnt)
	89	{
	90	if (mnt) {
	91	mnt->mnt_expiry_mark = 0;
751c404b	92	mntput_no_expire(mnt);
1da177e4 LT	93	}
	94	}
	95
1da177e4 LT	96	extern struct vfsmount do_kern_mount(const char fstype, int flags,
	97	const char name, void data);
	98
bb4a58bf TM	99	struct file_system_type;
	100	extern struct vfsmount vfs_kern_mount(struct file_system_type type,
	101	int flags, const char *name,
	102	void *data);
	103
1da177e4 LT	104	struct nameidata;
1da177e4 LT	105
8d66bf54 AV	106	struct path;
8d66bf54 AV	107	extern int do_add_mount(struct vfsmount newmnt, struct path path,
1da177e4 LT	108	int mnt_flags, struct list_head *fslist);
	109
	110	extern void mark_mounts_for_expiry(struct list_head *mounts);
	111
	112	extern spinlock_t vfsmount_lock;
d53d9f16	113	extern dev_t name_to_dev_t(char *name);
1da177e4	114
1da177e4	115	#endif /* _LINUX_MOUNT_H */