text: /* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> */
  
  #ifndef _LINUX_NFSD_FH_INT_H
  #define _LINUX_NFSD_FH_INT_H
  
  #include <linux/nfsd/nfsfh.h>
  
  enum nfsd_fsid {
  	FSID_DEV = 0,
  	FSID_NUM,
  	FSID_MAJOR_MINOR,
  	FSID_ENCODE_DEV,
  	FSID_UUID4_INUM,
  	FSID_UUID8,
  	FSID_UUID16,
  	FSID_UUID16_INUM,
  };
  
  enum fsid_source {
  	FSIDSOURCE_DEV,
  	FSIDSOURCE_FSID,
  	FSIDSOURCE_UUID,
  };
  extern enum fsid_source fsid_source(struct svc_fh *fhp);
  
  
  /* This might look a little large to "inline" but in all calls except
   * one, 'vers' is constant so moste of the function disappears.
   */
  static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
  			   u32 fsid, unsigned char *uuid)
  {
  	u32 *up;
  	switch(vers) {
  	case FSID_DEV:
  		fsidv[0] = htonl((MAJOR(dev)<<16) |
  				 MINOR(dev));
  		fsidv[1] = ino_t_to_u32(ino);
  		break;
  	case FSID_NUM:
  		fsidv[0] = fsid;
  		break;
  	case FSID_MAJOR_MINOR:
  		fsidv[0] = htonl(MAJOR(dev));
  		fsidv[1] = htonl(MINOR(dev));
  		fsidv[2] = ino_t_to_u32(ino);
  		break;
  
  	case FSID_ENCODE_DEV:
  		fsidv[0] = new_encode_dev(dev);
  		fsidv[1] = ino_t_to_u32(ino);
  		break;
  
  	case FSID_UUID4_INUM:
  		/* 4 byte fsid and inode number */
  		up = (u32*)uuid;
  		fsidv[0] = ino_t_to_u32(ino);
  		fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
  		break;
  
  	case FSID_UUID8:
  		/* 8 byte fsid  */
  		up = (u32*)uuid;
  		fsidv[0] = up[0] ^ up[2];
  		fsidv[1] = up[1] ^ up[3];
  		break;
  
  	case FSID_UUID16:
  		/* 16 byte fsid - NFSv3+ only */
  		memcpy(fsidv, uuid, 16);
  		break;
  
  	case FSID_UUID16_INUM:
  		/* 8 byte inode and 16 byte fsid */
  		*(u64*)fsidv = (u64)ino;
  		memcpy(fsidv+2, uuid, 16);
  		break;
  	default: BUG();
  	}
  }
  
  static inline int key_len(int type)
  {
  	switch(type) {
  	case FSID_DEV:		return 8;
  	case FSID_NUM: 		return 4;
  	case FSID_MAJOR_MINOR:	return 12;
  	case FSID_ENCODE_DEV:	return 8;
  	case FSID_UUID4_INUM:	return 8;
  	case FSID_UUID8:	return 8;
  	case FSID_UUID16:	return 16;
  	case FSID_UUID16_INUM:	return 24;
  	default: return 0;
  	}
  }
  
  /*
   * Shorthand for dprintk()'s
   */
  extern char * SVCFH_fmt(struct svc_fh *fhp);
  
  /*
   * Function prototypes
   */
  __be32	fh_verify(struct svc_rqst *, struct svc_fh *, int, int);
  __be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
  __be32	fh_update(struct svc_fh *);
  void	fh_put(struct svc_fh *);
  
  static __inline__ struct svc_fh *
  fh_copy(struct svc_fh *dst, struct svc_fh *src)
  {
  	WARN_ON(src->fh_dentry || src->fh_locked);
  			
  	*dst = *src;
  	return dst;
  }
  
  static inline void
  fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
  {
  	dst->fh_size = src->fh_size;
  	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
  }
  
  static __inline__ struct svc_fh *
  fh_init(struct svc_fh *fhp, int maxsize)
  {
  	memset(fhp, 0, sizeof(*fhp));
  	fhp->fh_maxsize = maxsize;
  	return fhp;
  }
  
  #ifdef CONFIG_NFSD_V3
  /*
   * Fill in the pre_op attr for the wcc data
   */
  static inline void
  fill_pre_wcc(struct svc_fh *fhp)
  {
  	struct inode    *inode;
  
  	inode = fhp->fh_dentry->d_inode;
  	if (!fhp->fh_pre_saved) {
  		fhp->fh_pre_mtime = inode->i_mtime;
  		fhp->fh_pre_ctime = inode->i_ctime;
  		fhp->fh_pre_size  = inode->i_size;
  		fhp->fh_pre_change = inode->i_version;
  		fhp->fh_pre_saved = 1;
  	}
  }
  
  extern void fill_post_wcc(struct svc_fh *);
  #else
  #define	fill_pre_wcc(ignored)
  #define fill_post_wcc(notused)
  #endif /* CONFIG_NFSD_V3 */
  
  
  /*
   * Lock a file handle/inode
   * NOTE: both fh_lock and fh_unlock are done "by hand" in
   * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
   * so, any changes here should be reflected there.
   */
  
  static inline void
  fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
  {
  	struct dentry	*dentry = fhp->fh_dentry;
  	struct inode	*inode;
  
  	BUG_ON(!dentry);
  
  	if (fhp->fh_locked) {
  		printk(KERN_WARNING "fh_lock: %s/%s already locked!\n",
  			dentry->d_parent->d_name.name, dentry->d_name.name);
  		return;
  	}
  
  	inode = dentry->d_inode;
  	mutex_lock_nested(&inode->i_mutex, subclass);
  	fill_pre_wcc(fhp);
  	fhp->fh_locked = 1;
  }
  
  static inline void
  fh_lock(struct svc_fh *fhp)
  {
  	fh_lock_nested(fhp, I_MUTEX_NORMAL);
  }
  
  /*
   * Unlock a file handle/inode
   */
  static inline void
  fh_unlock(struct svc_fh *fhp)
  {
  	BUG_ON(!fhp->fh_dentry);
  
  	if (fhp->fh_locked) {
  		fill_post_wcc(fhp);
  		mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex);
  		fhp->fh_locked = 0;
  	}
  }
  
  #endif /* _LINUX_NFSD_FH_INT_H */
  