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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
3 *
4 * Definitions for mount interface. This describes the in the kernel build
5 * linkedlist with mounted filesystems.
6 *
7 * Author: Marco van Wieringen <mvw@planets.elm.net>
8 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 */
10#ifndef _LINUX_MOUNT_H
11#define _LINUX_MOUNT_H
Linus Torvalds1da177e2005-04-16 15:20:36 -070012
Andrew Mortond53d9f12005-07-12 13:58:07 -070013#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/list.h>
Dave Hansen3d733632008-02-15 14:37:59 -080015#include <linux/nodemask.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/spinlock.h>
Nick Pigginb3e19d92011-01-07 17:50:11 +110017#include <linux/seqlock.h>
Arun Sharma600634972011-07-26 16:09:06 -070018#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
David Howells726c3342006-06-23 02:02:58 -070020struct super_block;
21struct vfsmount;
22struct dentry;
Kirill Korotaev6b3286e2006-12-08 02:37:56 -080023struct mnt_namespace;
David Howells726c3342006-06-23 02:02:58 -070024
Ram Pai07b20882005-11-07 17:19:07 -050025#define MNT_NOSUID 0x01
26#define MNT_NODEV 0x02
27#define MNT_NOEXEC 0x04
Christoph Hellwigfc33a7b2006-01-09 20:52:17 -080028#define MNT_NOATIME 0x08
29#define MNT_NODIRATIME 0x10
Valerie Henson47ae32d2006-12-13 00:34:34 -080030#define MNT_RELATIME 0x20
Dave Hansen2e4b7fc2008-02-15 14:38:00 -080031#define MNT_READONLY 0x40 /* does the user want this to be r/o? */
Miklos Szeredibf066c72006-01-08 01:03:19 -080032
Trond Myklebust5528f9112006-06-09 09:34:17 -040033#define MNT_SHRINKABLE 0x100
npiggin@suse.ded3ef3d72009-04-26 20:25:54 +100034#define MNT_WRITE_HOLD 0x200
Trond Myklebust5528f9112006-06-09 09:34:17 -040035
Christoph Hellwigfc33a7b2006-01-09 20:52:17 -080036#define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
37#define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
Valerie Aurora495d6c92010-01-26 14:20:47 -050038/*
39 * MNT_SHARED_MASK is the set of flags that should be cleared when a
40 * mount becomes shared. Currently, this is only the flag that says a
41 * mount cannot be bind mounted, since this is how we create a mount
42 * that shares events with another mount. If you add a new MNT_*
43 * flag, consider how it interacts with shared mounts.
44 */
45#define MNT_SHARED_MASK (MNT_UNBINDABLE)
Eric W. Biedermana6138db2014-07-28 16:26:53 -070046#define MNT_USER_SETTABLE_MASK (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \
47 | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \
48 | MNT_READONLY)
Eric W. Biederman9566d672014-07-28 17:26:07 -070049#define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME )
Valerie Aurora495d6c92010-01-26 14:20:47 -050050
Al Virof2ebb3a2014-02-27 09:35:45 -050051#define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \
52 MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Al Viro80893522010-02-05 09:30:46 -050054#define MNT_INTERNAL 0x4000
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Eric W. Biederman9566d672014-07-28 17:26:07 -070056#define MNT_LOCK_ATIME 0x040000
57#define MNT_LOCK_NOEXEC 0x080000
58#define MNT_LOCK_NOSUID 0x100000
59#define MNT_LOCK_NODEV 0x200000
Eric W. Biederman90563b12013-03-22 03:10:15 -070060#define MNT_LOCK_READONLY 0x400000
Eric W. Biederman5ff9d8a2013-03-29 21:04:39 -070061#define MNT_LOCKED 0x800000
Al Viro48a066e2013-09-29 22:06:07 -040062#define MNT_DOOMED 0x1000000
63#define MNT_SYNC_UMOUNT 0x2000000
Al Virof2ebb3a2014-02-27 09:35:45 -050064#define MNT_MARKED 0x4000000
Eric W. Biederman590ce4b2014-12-22 18:30:08 -060065#define MNT_UMOUNT 0x8000000
Eric W. Biederman90563b12013-03-22 03:10:15 -070066
Ram Pai07b20882005-11-07 17:19:07 -050067struct vfsmount {
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 struct dentry *mnt_root; /* root of the mounted tree */
69 struct super_block *mnt_sb; /* pointer to superblock */
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 int mnt_flags;
Daniel Rosenberg00fdd652016-10-26 15:29:51 -070071 void *data;
Kees Cook3859a272016-10-28 01:22:25 -070072} __randomize_layout;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
npiggin@suse.de96029c42009-04-26 20:25:55 +100074struct file; /* forward dec */
Al Viro3064c352014-08-07 09:12:31 -040075struct path;
npiggin@suse.de96029c42009-04-26 20:25:55 +100076
Dave Hansen83660252008-02-15 14:37:30 -080077extern int mnt_want_write(struct vfsmount *mnt);
npiggin@suse.de96029c42009-04-26 20:25:55 +100078extern int mnt_want_write_file(struct file *file);
79extern int mnt_clone_write(struct vfsmount *mnt);
Dave Hansen83660252008-02-15 14:37:30 -080080extern void mnt_drop_write(struct vfsmount *mnt);
Al Viro2a79f172011-12-09 08:06:57 -050081extern void mnt_drop_write_file(struct file *file);
Nick Pigginb3e19d92011-01-07 17:50:11 +110082extern void mntput(struct vfsmount *mnt);
83extern struct vfsmount *mntget(struct vfsmount *mnt);
Al Viroca71cf72016-11-20 19:45:28 -050084extern struct vfsmount *mnt_clone_internal(const struct path *path);
Dave Hansen83660252008-02-15 14:37:30 -080085extern int __mnt_is_readonly(struct vfsmount *mnt);
Andy Lutomirski380cf5b2016-06-23 16:41:05 -050086extern bool mnt_may_suid(struct vfsmount *mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
Miklos Szeredic771d682014-10-24 00:14:36 +020088struct path;
Al Viroca71cf72016-11-20 19:45:28 -050089extern struct vfsmount *clone_private_mount(const struct path *path);
Miklos Szeredic771d682014-10-24 00:14:36 +020090
Trond Myklebustbb4a58b2006-06-09 09:34:15 -040091struct file_system_type;
92extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
93 int flags, const char *name,
94 void *data);
Eric W. Biederman93faccbb2017-02-01 06:06:16 +130095extern struct vfsmount *vfs_submount(const struct dentry *mountpoint,
96 struct file_system_type *type,
97 const char *name, void *data);
Trond Myklebustbb4a58b2006-06-09 09:34:15 -040098
David Howellsea5b7782011-01-14 19:10:03 +000099extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100extern void mark_mounts_for_expiry(struct list_head *mounts);
101
Dan Ehrenberge6e20a72015-02-10 15:20:49 -0800102extern dev_t name_to_dev_t(const char *name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Eric W. Biedermand2921682016-09-28 00:27:17 -0500104extern unsigned int sysctl_mount_max;
105
Ian Kentc6609c02016-11-24 08:03:41 +1100106extern bool path_is_mountpoint(const struct path *path);
107
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108#endif /* _LINUX_MOUNT_H */