LXR linux/include/linux/mount.h

   1/*
   2 *
   3 * Definitions for mount interface. This describes the in the kernel build 
   4 * linkedlist with mounted filesystems.
   5 *
   6 * Author:  Marco van Wieringen <mvw@planets.elm.net>
   7 *
   8 */
   9#ifndef _LINUX_MOUNT_H
  10#define _LINUX_MOUNT_H
  11
  12#include <linux/types.h>
  13#include <linux/list.h>
  14#include <linux/nodemask.h>
  15#include <linux/spinlock.h>
  16#include <linux/seqlock.h>
  17#include <asm/atomic.h>
  18
  19struct super_block;
  20struct vfsmount;
  21struct dentry;
  22struct mnt_namespace;
  23
  24#define MNT_NOSUID      0x01
  25#define MNT_NODEV       0x02
  26#define MNT_NOEXEC      0x04
  27#define MNT_NOATIME     0x08
  28#define MNT_NODIRATIME  0x10
  29#define MNT_RELATIME    0x20
  30#define MNT_READONLY    0x40    /* does the user want this to be r/o? */
  31
  32#define MNT_SHRINKABLE  0x100
  33#define MNT_WRITE_HOLD  0x200
  34
  35#define MNT_SHARED      0x1000  /* if the vfsmount is a shared mount */
  36#define MNT_UNBINDABLE  0x2000  /* if the vfsmount is a unbindable mount */
  37/*
  38 * MNT_SHARED_MASK is the set of flags that should be cleared when a
  39 * mount becomes shared.  Currently, this is only the flag that says a
  40 * mount cannot be bind mounted, since this is how we create a mount
  41 * that shares events with another mount.  If you add a new MNT_*
  42 * flag, consider how it interacts with shared mounts.
  43 */
  44#define MNT_SHARED_MASK (MNT_UNBINDABLE)
  45#define MNT_PROPAGATION_MASK    (MNT_SHARED | MNT_UNBINDABLE)
  46
  47
  48#define MNT_INTERNAL    0x4000
  49
  50struct mnt_pcp {
  51        int mnt_count;
  52        int mnt_writers;
  53};
  54
  55struct vfsmount {
  56        struct list_head mnt_hash;
  57        struct vfsmount *mnt_parent;    /* fs we are mounted on */
  58        struct dentry *mnt_mountpoint;  /* dentry of mountpoint */
  59        struct dentry *mnt_root;        /* root of the mounted tree */
  60        struct super_block *mnt_sb;     /* pointer to superblock */
  61#ifdef CONFIG_SMP
  62        struct mnt_pcp __percpu *mnt_pcp;
  63        atomic_t mnt_longterm;          /* how many of the refs are longterm */
  64#else
  65        int mnt_count;
  66        int mnt_writers;
  67#endif
  68        struct list_head mnt_mounts;    /* list of children, anchored here */
  69        struct list_head mnt_child;     /* and going through their mnt_child */
  70        int mnt_flags;
  71        /* 4 bytes hole on 64bits arches without fsnotify */
  72#ifdef CONFIG_FSNOTIFY
  73        __u32 mnt_fsnotify_mask;
  74        struct hlist_head mnt_fsnotify_marks;
  75#endif
  76        const char *mnt_devname;        /* Name of device e.g. /dev/dsk/hda1 */
  77        struct list_head mnt_list;
  78        struct list_head mnt_expire;    /* link in fs-specific expiry list */
  79        struct list_head mnt_share;     /* circular list of shared mounts */
  80        struct list_head mnt_slave_list;/* list of slave mounts */
  81        struct list_head mnt_slave;     /* slave list entry */
  82        struct vfsmount *mnt_master;    /* slave is on master->mnt_slave_list */
  83        struct mnt_namespace *mnt_ns;   /* containing namespace */
  84        int mnt_id;                     /* mount identifier */
  85        int mnt_group_id;               /* peer group identifier */
  86        int mnt_expiry_mark;            /* true if marked for expiry */
  87        int mnt_pinned;
  88        int mnt_ghosts;
  89};
  90
  91struct file; /* forward dec */
  92
  93extern int mnt_want_write(struct vfsmount *mnt);
  94extern int mnt_want_write_file(struct file *file);
  95extern int mnt_clone_write(struct vfsmount *mnt);
  96extern void mnt_drop_write(struct vfsmount *mnt);
  97extern void mntput(struct vfsmount *mnt);
  98extern struct vfsmount *mntget(struct vfsmount *mnt);
  99extern void mnt_pin(struct vfsmount *mnt);
 100extern void mnt_unpin(struct vfsmount *mnt);
 101extern int __mnt_is_readonly(struct vfsmount *mnt);
 102
 103extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
 104                                      const char *name, void *data);
 105
 106struct file_system_type;
 107extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
 108                                      int flags, const char *name,
 109                                      void *data);
 110
 111extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
 112extern void mark_mounts_for_expiry(struct list_head *mounts);
 113
 114extern dev_t name_to_dev_t(char *name);
 115
 116#endif /* _LINUX_MOUNT_H */
 117