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  * Version: $Id: mount.h,v 2.0 1996/11/17 16:48:14 mvw Exp mvw $
   9  *
  10  */
  11 #ifndef _LINUX_MOUNT_H
  12 #define _LINUX_MOUNT_H
  13 #ifdef __KERNEL__
  14
  15 #include <linux/list.h>
  16 #include <linux/spinlock.h>
  17 #include <asm/atomic.h>
  18
  19 #define MNT_NOSUID      1
  20 #define MNT_NODEV       2
  21 #define MNT_NOEXEC      4
  22
  23 struct vfsmount
  24 {
  25         struct list_head mnt_hash;
  26         struct vfsmount *mnt_parent;    /* fs we are mounted on */
  27         struct dentry *mnt_mountpoint;  /* dentry of mountpoint */
  28         struct dentry *mnt_root;        /* root of the mounted tree */
  29         struct super_block *mnt_sb;     /* pointer to superblock */
  30         struct list_head mnt_mounts;    /* list of children, anchored here */
  31         struct list_head mnt_child;     /* and going through their mnt_child */
  32         atomic_t mnt_count;
  33         int mnt_flags;
  34         int mnt_expiry_mark;            /* true if marked for expiry */
  35         char *mnt_devname;              /* Name of device e.g. /dev/dsk/hda1 */
  36         struct list_head mnt_list;
  37         struct list_head mnt_fslink;    /* link in fs-specific expiry list */
  38         struct namespace *mnt_namespace; /* containing namespace */
  39 };
  40
  41 static inline struct vfsmount *mntget(struct vfsmount *mnt)
  42 {
  43         if (mnt)
  44                 atomic_inc(&mnt->mnt_count);
  45         return mnt;
  46 }
  47
  48 extern void __mntput(struct vfsmount *mnt);
  49
  50 static inline void _mntput(struct vfsmount *mnt)
  51 {
  52         if (mnt) {
  53                 if (atomic_dec_and_test(&mnt->mnt_count))
  54                         __mntput(mnt);
  55         }
  56 }
  57
  58 static inline void mntput(struct vfsmount *mnt)
  59 {
  60         if (mnt) {
  61                 mnt->mnt_expiry_mark = 0;
  62                 _mntput(mnt);
  63         }
  64 }
  65
  66 extern void free_vfsmnt(struct vfsmount *mnt);
  67 extern struct vfsmount *alloc_vfsmnt(const char *name);
  68 extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
  69                                       const char *name, void *data);
  70
  71 struct nameidata;
  72
  73 extern int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
  74                         int mnt_flags, struct list_head *fslist);
  75
  76 extern void mark_mounts_for_expiry(struct list_head *mounts);
  77
  78 extern spinlock_t vfsmount_lock;
  79
  80 #endif
  81 #endif /* _LINUX_MOUNT_H */