Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * |
| 4 | * Definitions for mount interface. This describes the in the kernel build |
| 5 | * linkedlist with mounted filesystems. |
| 6 | * |
| 7 | * Author: Marco van Wieringen <[email protected]> |
| 8 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | */ |
| 10 | #ifndef _LINUX_MOUNT_H |
| 11 | #define _LINUX_MOUNT_H |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
Andrew Morton | d53d9f1 | 2005-07-12 13:58:07 -0700 | [diff] [blame] | 13 | #include <linux/types.h> |
Al Viro | 59df85d | 2022-03-01 19:56:53 -0500 | [diff] [blame] | 14 | #include <asm/barrier.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 16 | struct super_block; |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 17 | struct dentry; |
Al Viro | 59df85d | 2022-03-01 19:56:53 -0500 | [diff] [blame] | 18 | struct user_namespace; |
| 19 | struct file_system_type; |
Al Viro | 8f291889 | 2018-11-04 06:48:34 -0500 | [diff] [blame] | 20 | struct fs_context; |
Al Viro | 59df85d | 2022-03-01 19:56:53 -0500 | [diff] [blame] | 21 | struct file; |
| 22 | struct path; |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 23 | |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 24 | #define MNT_NOSUID 0x01 |
| 25 | #define MNT_NODEV 0x02 |
| 26 | #define MNT_NOEXEC 0x04 |
Christoph Hellwig | fc33a7b | 2006-01-09 20:52:17 -0800 | [diff] [blame] | 27 | #define MNT_NOATIME 0x08 |
| 28 | #define MNT_NODIRATIME 0x10 |
Valerie Henson | 47ae32d | 2006-12-13 00:34:34 -0800 | [diff] [blame] | 29 | #define MNT_RELATIME 0x20 |
Dave Hansen | 2e4b7fc | 2008-02-15 14:38:00 -0800 | [diff] [blame] | 30 | #define MNT_READONLY 0x40 /* does the user want this to be r/o? */ |
Mattias Nissler | dab741e0 | 2020-08-27 11:09:46 -0600 | [diff] [blame] | 31 | #define MNT_NOSYMFOLLOW 0x80 |
Miklos Szeredi | bf066c7 | 2006-01-08 01:03:19 -0800 | [diff] [blame] | 32 | |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 33 | #define MNT_SHRINKABLE 0x100 |
[email protected] | d3ef3d7 | 2009-04-26 20:25:54 +1000 | [diff] [blame] | 34 | #define MNT_WRITE_HOLD 0x200 |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 35 | |
Christoph Hellwig | fc33a7b | 2006-01-09 20:52:17 -0800 | [diff] [blame] | 36 | #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */ |
| 37 | #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */ |
Valerie Aurora | 495d6c9 | 2010-01-26 14:20:47 -0500 | [diff] [blame] | 38 | /* |
| 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. Biederman | a6138db | 2014-07-28 16:26:53 -0700 | [diff] [blame] | 46 | #define MNT_USER_SETTABLE_MASK (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \ |
| 47 | | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \ |
Mattias Nissler | dab741e0 | 2020-08-27 11:09:46 -0600 | [diff] [blame] | 48 | | MNT_READONLY | MNT_NOSYMFOLLOW) |
Eric W. Biederman | 9566d67 | 2014-07-28 17:26:07 -0700 | [diff] [blame] | 49 | #define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME ) |
Valerie Aurora | 495d6c9 | 2010-01-26 14:20:47 -0500 | [diff] [blame] | 50 | |
Al Viro | f2ebb3a | 2014-02-27 09:35:45 -0500 | [diff] [blame] | 51 | #define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \ |
Miklos Szeredi | 9f6c61f | 2020-05-14 16:44:24 +0200 | [diff] [blame] | 52 | MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED | \ |
| 53 | MNT_CURSOR) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Al Viro | 8089352 | 2010-02-05 09:30:46 -0500 | [diff] [blame] | 55 | #define MNT_INTERNAL 0x4000 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
Eric W. Biederman | 9566d67 | 2014-07-28 17:26:07 -0700 | [diff] [blame] | 57 | #define MNT_LOCK_ATIME 0x040000 |
| 58 | #define MNT_LOCK_NOEXEC 0x080000 |
| 59 | #define MNT_LOCK_NOSUID 0x100000 |
| 60 | #define MNT_LOCK_NODEV 0x200000 |
Eric W. Biederman | 90563b1 | 2013-03-22 03:10:15 -0700 | [diff] [blame] | 61 | #define MNT_LOCK_READONLY 0x400000 |
Eric W. Biederman | 5ff9d8a | 2013-03-29 21:04:39 -0700 | [diff] [blame] | 62 | #define MNT_LOCKED 0x800000 |
Al Viro | 48a066e | 2013-09-29 22:06:07 -0400 | [diff] [blame] | 63 | #define MNT_DOOMED 0x1000000 |
| 64 | #define MNT_SYNC_UMOUNT 0x2000000 |
Al Viro | f2ebb3a | 2014-02-27 09:35:45 -0500 | [diff] [blame] | 65 | #define MNT_MARKED 0x4000000 |
Eric W. Biederman | 590ce4bc | 2014-12-22 18:30:08 -0600 | [diff] [blame] | 66 | #define MNT_UMOUNT 0x8000000 |
Miklos Szeredi | 9f6c61f | 2020-05-14 16:44:24 +0200 | [diff] [blame] | 67 | #define MNT_CURSOR 0x10000000 |
Eric W. Biederman | 90563b1 | 2013-03-22 03:10:15 -0700 | [diff] [blame] | 68 | |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 69 | struct vfsmount { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | struct dentry *mnt_root; /* root of the mounted tree */ |
| 71 | struct super_block *mnt_sb; /* pointer to superblock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | int mnt_flags; |
Christian Brauner | a643594 | 2021-01-21 14:19:20 +0100 | [diff] [blame] | 73 | struct user_namespace *mnt_userns; |
Kees Cook | 3859a27 | 2016-10-28 01:22:25 -0700 | [diff] [blame] | 74 | } __randomize_layout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
Christian Brauner | a643594 | 2021-01-21 14:19:20 +0100 | [diff] [blame] | 76 | static inline struct user_namespace *mnt_user_ns(const struct vfsmount *mnt) |
| 77 | { |
Christian Brauner | 9caccd4 | 2021-01-21 14:19:54 +0100 | [diff] [blame] | 78 | /* Pairs with smp_store_release() in do_idmap_mount(). */ |
| 79 | return smp_load_acquire(&mnt->mnt_userns); |
Christian Brauner | a643594 | 2021-01-21 14:19:20 +0100 | [diff] [blame] | 80 | } |
| 81 | |
Dave Hansen | 8366025 | 2008-02-15 14:37:30 -0800 | [diff] [blame] | 82 | extern int mnt_want_write(struct vfsmount *mnt); |
[email protected] | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 83 | extern int mnt_want_write_file(struct file *file); |
Dave Hansen | 8366025 | 2008-02-15 14:37:30 -0800 | [diff] [blame] | 84 | extern void mnt_drop_write(struct vfsmount *mnt); |
Al Viro | 2a79f17 | 2011-12-09 08:06:57 -0500 | [diff] [blame] | 85 | extern void mnt_drop_write_file(struct file *file); |
Nick Piggin | b3e19d9 | 2011-01-07 17:50:11 +1100 | [diff] [blame] | 86 | extern void mntput(struct vfsmount *mnt); |
| 87 | extern struct vfsmount *mntget(struct vfsmount *mnt); |
Al Viro | ca71cf7 | 2016-11-20 19:45:28 -0500 | [diff] [blame] | 88 | extern struct vfsmount *mnt_clone_internal(const struct path *path); |
David Howells | 43f5e65 | 2018-11-01 23:07:25 +0000 | [diff] [blame] | 89 | extern bool __mnt_is_readonly(struct vfsmount *mnt); |
Andy Lutomirski | 380cf5b | 2016-06-23 16:41:05 -0500 | [diff] [blame] | 90 | extern bool mnt_may_suid(struct vfsmount *mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | |
Al Viro | ca71cf7 | 2016-11-20 19:45:28 -0500 | [diff] [blame] | 92 | extern struct vfsmount *clone_private_mount(const struct path *path); |
Al Viro | 9419a31 | 2019-04-04 21:04:13 -0400 | [diff] [blame] | 93 | extern int __mnt_want_write(struct vfsmount *); |
| 94 | extern void __mnt_drop_write(struct vfsmount *); |
Miklos Szeredi | c771d68 | 2014-10-24 00:14:36 +0200 | [diff] [blame] | 95 | |
Al Viro | 8f291889 | 2018-11-04 06:48:34 -0500 | [diff] [blame] | 96 | extern struct vfsmount *fc_mount(struct fs_context *fc); |
| 97 | extern struct vfsmount *vfs_create_mount(struct fs_context *fc); |
Trond Myklebust | bb4a58b | 2006-06-09 09:34:15 -0400 | [diff] [blame] | 98 | extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, |
| 99 | int flags, const char *name, |
| 100 | void *data); |
Eric W. Biederman | 93faccbb | 2017-02-01 06:06:16 +1300 | [diff] [blame] | 101 | extern struct vfsmount *vfs_submount(const struct dentry *mountpoint, |
| 102 | struct file_system_type *type, |
| 103 | const char *name, void *data); |
Trond Myklebust | bb4a58b | 2006-06-09 09:34:15 -0400 | [diff] [blame] | 104 | |
David Howells | ea5b778 | 2011-01-14 19:10:03 +0000 | [diff] [blame] | 105 | extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | extern void mark_mounts_for_expiry(struct list_head *mounts); |
| 107 | |
Dan Ehrenberg | e6e20a7 | 2015-02-10 15:20:49 -0800 | [diff] [blame] | 108 | extern dev_t name_to_dev_t(const char *name); |
Ian Kent | c6609c0 | 2016-11-24 08:03:41 +1100 | [diff] [blame] | 109 | extern bool path_is_mountpoint(const struct path *path); |
| 110 | |
Al Viro | 70f8d9c | 2022-03-02 17:49:09 -0500 | [diff] [blame] | 111 | extern bool our_mnt(struct vfsmount *mnt); |
| 112 | |
| 113 | extern struct vfsmount *kern_mount(struct file_system_type *); |
| 114 | extern void kern_unmount(struct vfsmount *mnt); |
| 115 | extern int may_umount_tree(struct vfsmount *); |
| 116 | extern int may_umount(struct vfsmount *); |
| 117 | extern long do_mount(const char *, const char __user *, |
| 118 | const char *, unsigned long, void *); |
| 119 | extern struct vfsmount *collect_mounts(const struct path *); |
| 120 | extern void drop_collected_mounts(struct vfsmount *); |
| 121 | extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *, |
| 122 | struct vfsmount *); |
Miklos Szeredi | df820f8 | 2020-06-04 10:48:19 +0200 | [diff] [blame] | 123 | extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num); |
| 124 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | #endif /* _LINUX_MOUNT_H */ |