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/* SPDX-License-Identifier: GPL-2.0 */
/*
*
* Definitions for mount interface. This describes the in the kernel build
* linkedlist with mounted filesystems.
*
* Author: Marco van Wieringen <mvw@planets.elm.net>
*
*/
#ifndef _LINUX_MOUNT_H
#define _LINUX_MOUNT_H
#include <linux/types.h>
#include <asm/barrier.h>
struct super_block;
struct dentry;
struct user_namespace;
struct mnt_idmap;
struct file_system_type;
struct fs_context;
struct file;
struct path;
enum mount_flags {
MNT_NOSUID = 0x01,
MNT_NODEV = 0x02,
MNT_NOEXEC = 0x04,
MNT_NOATIME = 0x08,
MNT_NODIRATIME = 0x10,
MNT_RELATIME = 0x20,
MNT_READONLY = 0x40, /* does the user want this to be r/o? */
MNT_NOSYMFOLLOW = 0x80,
MNT_SHRINKABLE = 0x100,
MNT_WRITE_HOLD = 0x200,
MNT_SHARED = 0x1000, /* if the vfsmount is a shared mount */
MNT_UNBINDABLE = 0x2000, /* if the vfsmount is a unbindable mount */
MNT_INTERNAL = 0x4000,
MNT_LOCK_ATIME = 0x040000,
MNT_LOCK_NOEXEC = 0x080000,
MNT_LOCK_NOSUID = 0x100000,
MNT_LOCK_NODEV = 0x200000,
MNT_LOCK_READONLY = 0x400000,
MNT_LOCKED = 0x800000,
MNT_DOOMED = 0x1000000,
MNT_SYNC_UMOUNT = 0x2000000,
MNT_MARKED = 0x4000000,
MNT_UMOUNT = 0x8000000,
/*
* MNT_SHARED_MASK is the set of flags that should be cleared when a
* mount becomes shared. Currently, this is only the flag that says a
* mount cannot be bind mounted, since this is how we create a mount
* that shares events with another mount. If you add a new MNT_*
* flag, consider how it interacts with shared mounts.
*/
MNT_SHARED_MASK = MNT_UNBINDABLE,
MNT_USER_SETTABLE_MASK = MNT_NOSUID | MNT_NODEV | MNT_NOEXEC
| MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME
| MNT_READONLY | MNT_NOSYMFOLLOW,
MNT_ATIME_MASK = MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME,
MNT_INTERNAL_FLAGS = MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL |
MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED |
MNT_LOCKED,
};
struct vfsmount {
struct dentry *mnt_root; /* root of the mounted tree */
struct super_block *mnt_sb; /* pointer to superblock */
int mnt_flags;
struct mnt_idmap *mnt_idmap;
} __randomize_layout;
static inline struct mnt_idmap *mnt_idmap(const struct vfsmount *mnt)
{
/* Pairs with smp_store_release() in do_idmap_mount(). */
return READ_ONCE(mnt->mnt_idmap);
}
extern int mnt_want_write(struct vfsmount *mnt);
extern int mnt_want_write_file(struct file *file);
extern void mnt_drop_write(struct vfsmount *mnt);
extern void mnt_drop_write_file(struct file *file);
extern void mntput(struct vfsmount *mnt);
extern struct vfsmount *mntget(struct vfsmount *mnt);
extern void mnt_make_shortterm(struct vfsmount *mnt);
extern struct vfsmount *mnt_clone_internal(const struct path *path);
extern bool __mnt_is_readonly(struct vfsmount *mnt);
extern bool mnt_may_suid(struct vfsmount *mnt);
extern struct vfsmount *clone_private_mount(const struct path *path);
int mnt_get_write_access(struct vfsmount *mnt);
void mnt_put_write_access(struct vfsmount *mnt);
extern struct vfsmount *fc_mount(struct fs_context *fc);
extern struct vfsmount *vfs_create_mount(struct fs_context *fc);
extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
int flags, const char *name,
void *data);
extern struct vfsmount *vfs_submount(const struct dentry *mountpoint,
struct file_system_type *type,
const char *name, void *data);
extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
extern void mark_mounts_for_expiry(struct list_head *mounts);
extern bool path_is_mountpoint(const struct path *path);
extern bool our_mnt(struct vfsmount *mnt);
extern struct vfsmount *kern_mount(struct file_system_type *);
extern void kern_unmount(struct vfsmount *mnt);
extern int may_umount_tree(struct vfsmount *);
extern int may_umount(struct vfsmount *);
int do_mount(const char *, const char __user *,
const char *, unsigned long, void *);
extern struct vfsmount *collect_mounts(const struct path *);
extern void drop_collected_mounts(struct vfsmount *);
extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
struct vfsmount *);
extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num);
extern int cifs_root_data(char **dev, char **opts);
#endif /* _LINUX_MOUNT_H */