LXR linux-old/include/linux/fs

   1#ifndef _LINUX_FS_STRUCT_H
   2#define _LINUX_FS_STRUCT_H
   3#ifdef __KERNEL__
   4
   5struct fs_struct {
   6        atomic_t count;
   7        rwlock_t lock;
   8        int umask;
   9        struct dentry * root, * pwd, * altroot;
  10        struct vfsmount * rootmnt, * pwdmnt, * altrootmnt;
  11};
  12
  13#define INIT_FS { \
  14        ATOMIC_INIT(1), \
  15        RW_LOCK_UNLOCKED, \
  16        0022, \
  17        NULL, NULL, NULL, NULL, NULL, NULL \
  18}
  19
  20extern void exit_fs(struct task_struct *);
  21extern void set_fs_altroot(void);
  22
  23/*
  24 * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
  25 * It can block. Requires the big lock held.
  26 */
  27
  28static inline void set_fs_root(struct fs_struct *fs,
  29        struct vfsmount *mnt,
  30        struct dentry *dentry)
  31{
  32        struct dentry *old_root;
  33        struct vfsmount *old_rootmnt;
  34        write_lock(&fs->lock);
  35        old_root = fs->root;
  36        old_rootmnt = fs->rootmnt;
  37        fs->rootmnt = mntget(mnt);
  38        fs->root = dget(dentry);
  39        write_unlock(&fs->lock);
  40        if (old_root) {
  41                dput(old_root);
  42                mntput(old_rootmnt);
  43        }
  44}
  45
  46/*
  47 * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values.
  48 * It can block. Requires the big lock held.
  49 */
  50
  51static inline void set_fs_pwd(struct fs_struct *fs,
  52        struct vfsmount *mnt,
  53        struct dentry *dentry)
  54{
  55        struct dentry *old_pwd;
  56        struct vfsmount *old_pwdmnt;
  57        write_lock(&fs->lock);
  58        old_pwd = fs->pwd;
  59        old_pwdmnt = fs->pwdmnt;
  60        fs->pwdmnt = mntget(mnt);
  61        fs->pwd = dget(dentry);
  62        write_unlock(&fs->lock);
  63        if (old_pwd) {
  64                dput(old_pwd);
  65                mntput(old_pwdmnt);
  66        }
  67}
  68
  69struct fs_struct *copy_fs_struct(struct fs_struct *old);
  70void put_fs_struct(struct fs_struct *fs);
  71
  72#endif
  73#endif
  74