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