/* * * 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 <linux/list.h> #include <linux/nodemask.h> #include <linux/spinlock.h> #include <asm/atomic.h> struct super_block; struct vfsmount; struct dentry; struct mnt_namespace; #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_STRICTATIME 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 */ #define MNT_PNODE_MASK 0x3000 /* propagation flag mask */ struct vfsmount { struct list_head mnt_hash; struct vfsmount *mnt_parent; /* fs we are mounted on */ struct dentry *mnt_mountpoint; /* dentry of mountpoint */ struct dentry *mnt_root; /* root of the mounted tree */ struct super_block *mnt_sb; /* pointer to superblock */ struct list_head mnt_mounts; /* list of children, anchored here */ struct list_head mnt_child; /* and going through their mnt_child */ int mnt_flags; /* 4 bytes hole on 64bits arches */ const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ struct list_head mnt_list; struct list_head mnt_expire; /* link in fs-specific expiry list */ struct list_head mnt_share; /* circular list of shared mounts */ struct list_head mnt_slave_list;/* list of slave mounts */ struct list_head mnt_slave; /* slave list entry */ struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */ struct mnt_namespace *mnt_ns; /* containing namespace */ int mnt_id; /* mount identifier */ int mnt_group_id; /* peer group identifier */ /* * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount * to let these frequently modified fields in a separate cache line * (so that reads of mnt_flags wont ping-pong on SMP machines) */ atomic_t mnt_count; int mnt_expiry_mark; /* true if marked for expiry */ int mnt_pinned; int mnt_ghosts; #ifdef CONFIG_SMP int *mnt_writers; #else int mnt_writers; #endif }; static inline int *get_mnt_writers_ptr(struct vfsmount *mnt) { #ifdef CONFIG_SMP return mnt->mnt_writers; #else return &mnt->mnt_writers; #endif } static inline struct vfsmount *mntget(struct vfsmount *mnt) { if (mnt) atomic_inc(&mnt->mnt_count); return mnt; } struct file; /* forward dec */ extern int mnt_want_write(struct vfsmount *mnt); extern int mnt_want_write_file(struct file *file); extern int mnt_clone_write(struct vfsmount *mnt); extern void mnt_drop_write(struct vfsmount *mnt); extern void mntput_no_expire(struct vfsmount *mnt); extern void mnt_pin(struct vfsmount *mnt); extern void mnt_unpin(struct vfsmount *mnt); extern int __mnt_is_readonly(struct vfsmount *mnt); static inline void mntput(struct vfsmount *mnt) { if (mnt) { mnt->mnt_expiry_mark = 0; mntput_no_expire(mnt); } } extern struct vfsmount *do_kern_mount(const char *fstype, int flags, const char *name, void *data); struct file_system_type; extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data); struct nameidata; struct path; extern int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags, struct list_head *fslist); extern void mark_mounts_for_expiry(struct list_head *mounts); extern spinlock_t vfsmount_lock; extern dev_t name_to_dev_t(char *name); #endif /* _LINUX_MOUNT_H */