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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 */
9#ifndef _LINUX_MOUNT_H
10#define _LINUX_MOUNT_H
Linus Torvalds1da177e2005-04-16 15:20:36 -070011
Andrew Mortond53d9f12005-07-12 13:58:07 -070012#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/list.h>
Dave Hansen3d733632008-02-15 14:37:59 -080014#include <linux/nodemask.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/spinlock.h>
Nick Pigginb3e19d92011-01-07 17:50:11 +110016#include <linux/seqlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <asm/atomic.h>
18
David Howells726c3342006-06-23 02:02:58 -070019struct super_block;
20struct vfsmount;
21struct dentry;
Kirill Korotaev6b3286e2006-12-08 02:37:56 -080022struct mnt_namespace;
David Howells726c3342006-06-23 02:02:58 -070023
Ram Pai07b20882005-11-07 17:19:07 -050024#define MNT_NOSUID 0x01
25#define MNT_NODEV 0x02
26#define MNT_NOEXEC 0x04
Christoph Hellwigfc33a7b2006-01-09 20:52:17 -080027#define MNT_NOATIME 0x08
28#define MNT_NODIRATIME 0x10
Valerie Henson47ae32d2006-12-13 00:34:34 -080029#define MNT_RELATIME 0x20
Dave Hansen2e4b7fc2008-02-15 14:38:00 -080030#define MNT_READONLY 0x40 /* does the user want this to be r/o? */
Miklos Szeredibf066c72006-01-08 01:03:19 -080031
Trond Myklebust5528f9112006-06-09 09:34:17 -040032#define MNT_SHRINKABLE 0x100
npiggin@suse.ded3ef3d72009-04-26 20:25:54 +100033#define MNT_WRITE_HOLD 0x200
Trond Myklebust5528f9112006-06-09 09:34:17 -040034
Christoph Hellwigfc33a7b2006-01-09 20:52:17 -080035#define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
36#define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
Valerie Aurora495d6c92010-01-26 14:20:47 -050037/*
38 * MNT_SHARED_MASK is the set of flags that should be cleared when a
39 * mount becomes shared. Currently, this is only the flag that says a
40 * mount cannot be bind mounted, since this is how we create a mount
41 * that shares events with another mount. If you add a new MNT_*
42 * flag, consider how it interacts with shared mounts.
43 */
44#define MNT_SHARED_MASK (MNT_UNBINDABLE)
45#define MNT_PROPAGATION_MASK (MNT_SHARED | MNT_UNBINDABLE)
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Al Viro80893522010-02-05 09:30:46 -050048#define MNT_INTERNAL 0x4000
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Nick Pigginb3e19d92011-01-07 17:50:11 +110050struct mnt_pcp {
51 int mnt_count;
52 int mnt_writers;
53};
54
Ram Pai07b20882005-11-07 17:19:07 -050055struct vfsmount {
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 struct list_head mnt_hash;
57 struct vfsmount *mnt_parent; /* fs we are mounted on */
58 struct dentry *mnt_mountpoint; /* dentry of mountpoint */
59 struct dentry *mnt_root; /* root of the mounted tree */
60 struct super_block *mnt_sb; /* pointer to superblock */
Nick Pigginb3e19d92011-01-07 17:50:11 +110061#ifdef CONFIG_SMP
62 struct mnt_pcp __percpu *mnt_pcp;
Al Virof03c6592011-01-14 22:30:21 -050063 atomic_t mnt_longterm; /* how many of the refs are longterm */
Nick Pigginb3e19d92011-01-07 17:50:11 +110064#else
65 int mnt_count;
66 int mnt_writers;
67#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 struct list_head mnt_mounts; /* list of children, anchored here */
69 struct list_head mnt_child; /* and going through their mnt_child */
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 int mnt_flags;
Andreas Gruenbacher2504c5d2009-12-17 21:24:27 -050071 /* 4 bytes hole on 64bits arches without fsnotify */
72#ifdef CONFIG_FSNOTIFY
73 __u32 mnt_fsnotify_mask;
74 struct hlist_head mnt_fsnotify_marks;
75#endif
Li Zefan88b38782008-07-21 18:06:36 +080076 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 struct list_head mnt_list;
Miklos Szeredi55e700b2005-07-07 17:57:30 -070078 struct list_head mnt_expire; /* link in fs-specific expiry list */
Ram Pai03e06e62005-11-07 17:19:33 -050079 struct list_head mnt_share; /* circular list of shared mounts */
Ram Paia58b0eb2005-11-07 17:20:48 -050080 struct list_head mnt_slave_list;/* list of slave mounts */
81 struct list_head mnt_slave; /* slave list entry */
82 struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */
Kirill Korotaev6b3286e2006-12-08 02:37:56 -080083 struct mnt_namespace *mnt_ns; /* containing namespace */
Miklos Szeredi73cd49e2008-03-26 22:11:34 +010084 int mnt_id; /* mount identifier */
Miklos Szeredi719f5d72008-03-27 13:06:23 +010085 int mnt_group_id; /* peer group identifier */
Eric Dumazet4ba4d4c2007-02-10 01:44:48 -080086 int mnt_expiry_mark; /* true if marked for expiry */
Al Viro7b7b1ac2005-11-07 17:13:39 -050087 int mnt_pinned;
Al Viro7c4b93d2008-03-21 23:59:49 -040088 int mnt_ghosts;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089};
90
npiggin@suse.de96029c42009-04-26 20:25:55 +100091struct file; /* forward dec */
92
Dave Hansen83660252008-02-15 14:37:30 -080093extern int mnt_want_write(struct vfsmount *mnt);
npiggin@suse.de96029c42009-04-26 20:25:55 +100094extern int mnt_want_write_file(struct file *file);
95extern int mnt_clone_write(struct vfsmount *mnt);
Dave Hansen83660252008-02-15 14:37:30 -080096extern void mnt_drop_write(struct vfsmount *mnt);
Nick Pigginb3e19d92011-01-07 17:50:11 +110097extern void mntput(struct vfsmount *mnt);
98extern struct vfsmount *mntget(struct vfsmount *mnt);
Al Viro7b7b1ac2005-11-07 17:13:39 -050099extern void mnt_pin(struct vfsmount *mnt);
100extern void mnt_unpin(struct vfsmount *mnt);
Dave Hansen83660252008-02-15 14:37:30 -0800101extern int __mnt_is_readonly(struct vfsmount *mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
104 const char *name, void *data);
105
Trond Myklebustbb4a58b2006-06-09 09:34:15 -0400106struct file_system_type;
107extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
108 int flags, const char *name,
109 void *data);
110
David Howellsea5b7782011-01-14 19:10:03 +0000111extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112extern void mark_mounts_for_expiry(struct list_head *mounts);
113
Andrew Mortond53d9f12005-07-12 13:58:07 -0700114extern dev_t name_to_dev_t(char *name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116#endif /* _LINUX_MOUNT_H */