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 20struct super_block; 21struct vfsmount; 22struct dentry; 23struct mnt_namespace; 24struct 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 68struct 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 74struct file; /* forward dec */ 75struct path; 76 77extern int mnt_want_write(struct vfsmount *mnt); 78extern int mnt_want_write_file(struct file *file); 79extern int mnt_clone_write(struct vfsmount *mnt); 80extern void mnt_drop_write(struct vfsmount *mnt); 81extern void mnt_drop_write_file(struct file *file); 82extern void mntput(struct vfsmount *mnt); 83extern struct vfsmount *mntget(struct vfsmount *mnt); 84extern struct vfsmount *mnt_clone_internal(const struct path *path); 85extern bool __mnt_is_readonly(struct vfsmount *mnt); 86extern bool mnt_may_suid(struct vfsmount *mnt); 87 88struct path; 89extern struct vfsmount *clone_private_mount(const struct path *path); 90extern int __mnt_want_write(struct vfsmount *); 91extern void __mnt_drop_write(struct vfsmount *); 92 93struct file_system_type; 94extern struct vfsmount *fc_mount(struct fs_context *fc); 95extern struct vfsmount *vfs_create_mount(struct fs_context *fc); 96extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, 97 int flags, const char *name, 98 void *data); 99extern struct vfsmount *vfs_submount(const struct dentry *mountpoint, 100 struct file_system_type *type, 101 const char *name, void *data); 102 103extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); 104extern void mark_mounts_for_expiry(struct list_head *mounts); 105 106extern dev_t name_to_dev_t(const char *name); 107 108extern unsigned int sysctl_mount_max; 109 110extern bool path_is_mountpoint(const struct path *path); 111 112#endif /* _LINUX_MOUNT_H */ 113