diff options
Diffstat (limited to 'include/linux/mount.h')
| -rw-r--r-- | include/linux/mount.h | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/include/linux/mount.h b/include/linux/mount.h new file mode 100644 index 000000000..55a4abaf6 --- /dev/null +++ b/include/linux/mount.h @@ -0,0 +1,125 @@ +/* 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 file_system_type; +struct fs_context; +struct file; +struct path; + +#define MNT_NOSUID 0x01 +#define MNT_NODEV 0x02 +#define MNT_NOEXEC 0x04 +#define MNT_NOATIME 0x08 +#define MNT_NODIRATIME 0x10 +#define MNT_RELATIME 0x20 +#define MNT_READONLY 0x40 /* does the user want this to be r/o? */ +#define MNT_NOSYMFOLLOW 0x80 + +#define MNT_SHRINKABLE 0x100 +#define MNT_WRITE_HOLD 0x200 + +#define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */ +#define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */ +/* + * 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. + */ +#define MNT_SHARED_MASK (MNT_UNBINDABLE) +#define MNT_USER_SETTABLE_MASK (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \ + | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \ + | MNT_READONLY | MNT_NOSYMFOLLOW) +#define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME ) + +#define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \ + MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED | \ + MNT_CURSOR) + +#define MNT_INTERNAL 0x4000 + +#define MNT_LOCK_ATIME 0x040000 +#define MNT_LOCK_NOEXEC 0x080000 +#define MNT_LOCK_NOSUID 0x100000 +#define MNT_LOCK_NODEV 0x200000 +#define MNT_LOCK_READONLY 0x400000 +#define MNT_LOCKED 0x800000 +#define MNT_DOOMED 0x1000000 +#define MNT_SYNC_UMOUNT 0x2000000 +#define MNT_MARKED 0x4000000 +#define MNT_UMOUNT 0x8000000 +#define MNT_CURSOR 0x10000000 + +struct vfsmount { + struct dentry *mnt_root; /* root of the mounted tree */ + struct super_block *mnt_sb; /* pointer to superblock */ + int mnt_flags; + struct user_namespace *mnt_userns; +} __randomize_layout; + +static inline struct user_namespace *mnt_user_ns(const struct vfsmount *mnt) +{ + /* Pairs with smp_store_release() in do_idmap_mount(). */ + return smp_load_acquire(&mnt->mnt_userns); +} + +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 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); +extern int __mnt_want_write(struct vfsmount *); +extern void __mnt_drop_write(struct vfsmount *); + +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 dev_t name_to_dev_t(const char *name); +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 *); +extern long 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); + +#endif /* _LINUX_MOUNT_H */ |