1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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 <mvw@planets.elm.net> |
8 | * |
9 | */ |
10 | #ifndef _LINUX_MOUNT_H |
11 | #define _LINUX_MOUNT_H |
12 | |
13 | #include <linux/types.h> |
14 | #include <linux/list.h> |
15 | #include <linux/nodemask.h> |
16 | #include <linux/spinlock.h> |
17 | #include <linux/seqlock.h> |
18 | #include <linux/atomic.h> |
19 | |
20 | struct super_block; |
21 | struct vfsmount; |
22 | struct dentry; |
23 | struct mnt_namespace; |
24 | struct fs_context; |
25 | |
26 | #define MNT_NOSUID 0x01 |
27 | #define MNT_NODEV 0x02 |
28 | #define MNT_NOEXEC 0x04 |
29 | #define MNT_NOATIME 0x08 |
30 | #define MNT_NODIRATIME 0x10 |
31 | #define MNT_RELATIME 0x20 |
32 | #define MNT_READONLY 0x40 /* does the user want this to be r/o? */ |
33 | |
34 | #define MNT_SHRINKABLE 0x100 |
35 | #define MNT_WRITE_HOLD 0x200 |
36 | |
37 | #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */ |
38 | #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */ |
39 | /* |
40 | * MNT_SHARED_MASK is the set of flags that should be cleared when a |
41 | * mount becomes shared. Currently, this is only the flag that says a |
42 | * mount cannot be bind mounted, since this is how we create a mount |
43 | * that shares events with another mount. If you add a new MNT_* |
44 | * flag, consider how it interacts with shared mounts. |
45 | */ |
46 | #define MNT_SHARED_MASK (MNT_UNBINDABLE) |
47 | #define MNT_USER_SETTABLE_MASK (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \ |
48 | | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \ |
49 | | MNT_READONLY) |
50 | #define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME ) |
51 | |
52 | #define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \ |
53 | MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED) |
54 | |
55 | #define MNT_INTERNAL 0x4000 |
56 | |
57 | #define MNT_LOCK_ATIME 0x040000 |
58 | #define MNT_LOCK_NOEXEC 0x080000 |
59 | #define MNT_LOCK_NOSUID 0x100000 |
60 | #define MNT_LOCK_NODEV 0x200000 |
61 | #define MNT_LOCK_READONLY 0x400000 |
62 | #define MNT_LOCKED 0x800000 |
63 | #define MNT_DOOMED 0x1000000 |
64 | #define MNT_SYNC_UMOUNT 0x2000000 |
65 | #define MNT_MARKED 0x4000000 |
66 | #define MNT_UMOUNT 0x8000000 |
67 | |
68 | struct vfsmount { |
69 | struct dentry *mnt_root; /* root of the mounted tree */ |
70 | struct super_block *mnt_sb; /* pointer to superblock */ |
71 | int mnt_flags; |
72 | } __randomize_layout; |
73 | |
74 | struct file; /* forward dec */ |
75 | struct path; |
76 | |
77 | extern int mnt_want_write(struct vfsmount *mnt); |
78 | extern int mnt_want_write_file(struct file *file); |
79 | extern int mnt_clone_write(struct vfsmount *mnt); |
80 | extern void mnt_drop_write(struct vfsmount *mnt); |
81 | extern void mnt_drop_write_file(struct file *file); |
82 | extern void mntput(struct vfsmount *mnt); |
83 | extern struct vfsmount *mntget(struct vfsmount *mnt); |
84 | extern struct vfsmount *mnt_clone_internal(const struct path *path); |
85 | extern bool __mnt_is_readonly(struct vfsmount *mnt); |
86 | extern bool mnt_may_suid(struct vfsmount *mnt); |
87 | |
88 | struct path; |
89 | extern struct vfsmount *clone_private_mount(const struct path *path); |
90 | |
91 | struct file_system_type; |
92 | extern struct vfsmount *fc_mount(struct fs_context *fc); |
93 | extern struct vfsmount *vfs_create_mount(struct fs_context *fc); |
94 | extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, |
95 | int flags, const char *name, |
96 | void *data); |
97 | extern struct vfsmount *vfs_submount(const struct dentry *mountpoint, |
98 | struct file_system_type *type, |
99 | const char *name, void *data); |
100 | |
101 | extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); |
102 | extern void mark_mounts_for_expiry(struct list_head *mounts); |
103 | |
104 | extern dev_t name_to_dev_t(const char *name); |
105 | |
106 | extern unsigned int sysctl_mount_max; |
107 | |
108 | extern bool path_is_mountpoint(const struct path *path); |
109 | |
110 | #endif /* _LINUX_MOUNT_H */ |
111 | |