1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * 4*4882a593Smuzhiyun * Definitions for mount interface. This describes the in the kernel build 5*4882a593Smuzhiyun * linkedlist with mounted filesystems. 6*4882a593Smuzhiyun * 7*4882a593Smuzhiyun * Author: Marco van Wieringen <mvw@planets.elm.net> 8*4882a593Smuzhiyun * 9*4882a593Smuzhiyun */ 10*4882a593Smuzhiyun #ifndef _LINUX_MOUNT_H 11*4882a593Smuzhiyun #define _LINUX_MOUNT_H 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun #include <linux/types.h> 14*4882a593Smuzhiyun #include <linux/list.h> 15*4882a593Smuzhiyun #include <linux/nodemask.h> 16*4882a593Smuzhiyun #include <linux/spinlock.h> 17*4882a593Smuzhiyun #include <linux/seqlock.h> 18*4882a593Smuzhiyun #include <linux/atomic.h> 19*4882a593Smuzhiyun #include <linux/android_kabi.h> 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun struct super_block; 22*4882a593Smuzhiyun struct vfsmount; 23*4882a593Smuzhiyun struct dentry; 24*4882a593Smuzhiyun struct mnt_namespace; 25*4882a593Smuzhiyun struct fs_context; 26*4882a593Smuzhiyun 27*4882a593Smuzhiyun #define MNT_NOSUID 0x01 28*4882a593Smuzhiyun #define MNT_NODEV 0x02 29*4882a593Smuzhiyun #define MNT_NOEXEC 0x04 30*4882a593Smuzhiyun #define MNT_NOATIME 0x08 31*4882a593Smuzhiyun #define MNT_NODIRATIME 0x10 32*4882a593Smuzhiyun #define MNT_RELATIME 0x20 33*4882a593Smuzhiyun #define MNT_READONLY 0x40 /* does the user want this to be r/o? */ 34*4882a593Smuzhiyun #define MNT_NOSYMFOLLOW 0x80 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun #define MNT_SHRINKABLE 0x100 37*4882a593Smuzhiyun #define MNT_WRITE_HOLD 0x200 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */ 40*4882a593Smuzhiyun #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */ 41*4882a593Smuzhiyun /* 42*4882a593Smuzhiyun * MNT_SHARED_MASK is the set of flags that should be cleared when a 43*4882a593Smuzhiyun * mount becomes shared. Currently, this is only the flag that says a 44*4882a593Smuzhiyun * mount cannot be bind mounted, since this is how we create a mount 45*4882a593Smuzhiyun * that shares events with another mount. If you add a new MNT_* 46*4882a593Smuzhiyun * flag, consider how it interacts with shared mounts. 47*4882a593Smuzhiyun */ 48*4882a593Smuzhiyun #define MNT_SHARED_MASK (MNT_UNBINDABLE) 49*4882a593Smuzhiyun #define MNT_USER_SETTABLE_MASK (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \ 50*4882a593Smuzhiyun | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \ 51*4882a593Smuzhiyun | MNT_READONLY | MNT_NOSYMFOLLOW) 52*4882a593Smuzhiyun #define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME ) 53*4882a593Smuzhiyun 54*4882a593Smuzhiyun #define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \ 55*4882a593Smuzhiyun MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED | \ 56*4882a593Smuzhiyun MNT_CURSOR) 57*4882a593Smuzhiyun 58*4882a593Smuzhiyun #define MNT_INTERNAL 0x4000 59*4882a593Smuzhiyun 60*4882a593Smuzhiyun #define MNT_LOCK_ATIME 0x040000 61*4882a593Smuzhiyun #define MNT_LOCK_NOEXEC 0x080000 62*4882a593Smuzhiyun #define MNT_LOCK_NOSUID 0x100000 63*4882a593Smuzhiyun #define MNT_LOCK_NODEV 0x200000 64*4882a593Smuzhiyun #define MNT_LOCK_READONLY 0x400000 65*4882a593Smuzhiyun #define MNT_LOCKED 0x800000 66*4882a593Smuzhiyun #define MNT_DOOMED 0x1000000 67*4882a593Smuzhiyun #define MNT_SYNC_UMOUNT 0x2000000 68*4882a593Smuzhiyun #define MNT_MARKED 0x4000000 69*4882a593Smuzhiyun #define MNT_UMOUNT 0x8000000 70*4882a593Smuzhiyun #define MNT_CURSOR 0x10000000 71*4882a593Smuzhiyun 72*4882a593Smuzhiyun struct vfsmount { 73*4882a593Smuzhiyun struct dentry *mnt_root; /* root of the mounted tree */ 74*4882a593Smuzhiyun struct super_block *mnt_sb; /* pointer to superblock */ 75*4882a593Smuzhiyun int mnt_flags; 76*4882a593Smuzhiyun 77*4882a593Smuzhiyun ANDROID_KABI_RESERVE(1); 78*4882a593Smuzhiyun ANDROID_KABI_RESERVE(2); 79*4882a593Smuzhiyun ANDROID_KABI_RESERVE(3); 80*4882a593Smuzhiyun ANDROID_KABI_RESERVE(4); 81*4882a593Smuzhiyun } __randomize_layout; 82*4882a593Smuzhiyun 83*4882a593Smuzhiyun struct file; /* forward dec */ 84*4882a593Smuzhiyun struct path; 85*4882a593Smuzhiyun 86*4882a593Smuzhiyun extern int mnt_want_write(struct vfsmount *mnt); 87*4882a593Smuzhiyun extern int mnt_want_write_file(struct file *file); 88*4882a593Smuzhiyun extern int mnt_clone_write(struct vfsmount *mnt); 89*4882a593Smuzhiyun extern void mnt_drop_write(struct vfsmount *mnt); 90*4882a593Smuzhiyun extern void mnt_drop_write_file(struct file *file); 91*4882a593Smuzhiyun extern void mntput(struct vfsmount *mnt); 92*4882a593Smuzhiyun extern struct vfsmount *mntget(struct vfsmount *mnt); 93*4882a593Smuzhiyun extern struct vfsmount *mnt_clone_internal(const struct path *path); 94*4882a593Smuzhiyun extern bool __mnt_is_readonly(struct vfsmount *mnt); 95*4882a593Smuzhiyun extern bool mnt_may_suid(struct vfsmount *mnt); 96*4882a593Smuzhiyun 97*4882a593Smuzhiyun struct path; 98*4882a593Smuzhiyun extern struct vfsmount *clone_private_mount(const struct path *path); 99*4882a593Smuzhiyun extern int __mnt_want_write(struct vfsmount *); 100*4882a593Smuzhiyun extern void __mnt_drop_write(struct vfsmount *); 101*4882a593Smuzhiyun 102*4882a593Smuzhiyun struct file_system_type; 103*4882a593Smuzhiyun extern struct vfsmount *fc_mount(struct fs_context *fc); 104*4882a593Smuzhiyun extern struct vfsmount *vfs_create_mount(struct fs_context *fc); 105*4882a593Smuzhiyun extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, 106*4882a593Smuzhiyun int flags, const char *name, 107*4882a593Smuzhiyun void *data); 108*4882a593Smuzhiyun extern struct vfsmount *vfs_submount(const struct dentry *mountpoint, 109*4882a593Smuzhiyun struct file_system_type *type, 110*4882a593Smuzhiyun const char *name, void *data); 111*4882a593Smuzhiyun 112*4882a593Smuzhiyun extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); 113*4882a593Smuzhiyun extern void mark_mounts_for_expiry(struct list_head *mounts); 114*4882a593Smuzhiyun 115*4882a593Smuzhiyun extern dev_t name_to_dev_t(const char *name); 116*4882a593Smuzhiyun 117*4882a593Smuzhiyun extern unsigned int sysctl_mount_max; 118*4882a593Smuzhiyun 119*4882a593Smuzhiyun extern bool path_is_mountpoint(const struct path *path); 120*4882a593Smuzhiyun 121*4882a593Smuzhiyun extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num); 122*4882a593Smuzhiyun 123*4882a593Smuzhiyun #endif /* _LINUX_MOUNT_H */ 124