344 lines
		
	
	
		
			8.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			344 lines
		
	
	
		
			8.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
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/* This file contains the routines related to vnodes.
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 * The entry points are:
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 *      
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 *  get_vnode - increase counter and get details of an inode
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 *  get_free_vnode - get a pointer to a free vnode obj
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 *  find_vnode - find a vnode according to the FS endpoint and the inode num.  
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 *  dup_vnode - duplicate vnode (i.e. increase counter)
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 *  put_vnode - drop vnode (i.e. decrease counter)  
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 *  
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 *  Jul 2006 (Balazs Gerofi)
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 */
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#include "fs.h"
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#include "vnode.h"
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#include "vmnt.h"
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#include "fproc.h"
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#include "file.h"
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#include <minix/vfsif.h>
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/*===========================================================================*
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 *				get_vnode				     *
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 *===========================================================================*/
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PUBLIC struct vnode *get_vnode(int fs_e, int inode_nr)
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{
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/* get_vnode() is called to get the details of the specified inode.
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 * Note that inode's usage counter in the FS is supposed to be incremented.
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 */
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  struct vnode *vp, *vp2;
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  struct vmnt *vmp;
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  /* Request & response structures */
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  struct node_req req;
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  struct node_details res;
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  /* XXX remove this when debugging is complete */
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  if (find_vnode(fs_e, inode_nr) != NULL)
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	panic(__FILE__, "get_vnode: vnode already present", NO_NUM);
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  /* Check whether a free vnode is avaliable */
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  if ((vp = get_free_vnode(__FILE__, __LINE__)) == NIL_VNODE) {
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        printf("VFSget_vnode: no vnode available\n");
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        return NIL_VNODE;
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  }
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  /* Fill req struct */
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  req.inode_nr = inode_nr;
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  req.fs_e = fs_e;
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  /* Send request to FS */
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  if (req_getnode(&req, &res) != OK) {
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        printf("VFSget_vnode: couldn't find vnode\n"); 
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        return NIL_VNODE;
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  }
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  /* Fill in the free vnode's fields and return it */
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  vp->v_fs_e = res.fs_e;
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  vp->v_inode_nr = res.inode_nr;
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  vp->v_mode = res.fmode;
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  vp->v_size = res.fsize;
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  vp->v_sdev = res.dev;
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  /* Find corresponding virtual mount object */
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  if ( (vmp = find_vmnt(vp->v_fs_e)) == NIL_VMNT)
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        printf("VFS: vmnt not found by get_vnode()\n");
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  vp->v_vmnt = vmp; 
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  vp->v_dev = vmp->m_dev;
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  vp->v_fs_count = 1;
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  vp->v_ref_count = 1;
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  return vp; 
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}
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/*===========================================================================*
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 *				get_vnode				     *
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 *===========================================================================*/
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PUBLIC struct vnode *get_vnode_x(int fs_e, int inode_nr)
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{
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/* get_vnode() is called to get the details of the specified inode.
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 * Note that inode's usage counter in the FS is supposed to be incremented.
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 */
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  struct vnode *vp, *vp2;
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  struct vmnt *vmp;
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  /* Request & response structures */
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  struct node_req req;
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  struct node_details res;
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  vp= find_vnode(fs_e, inode_nr);
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  if (vp)
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  {
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	vp->v_ref_count++;
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	return vp;
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  }
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  return get_vnode(fs_e, inode_nr);
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}
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/*===========================================================================*
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 *				get_free_vnode				     *
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 *===========================================================================*/
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PUBLIC struct vnode *get_free_vnode(file, line)
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char *file;
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int line;
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{
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/* Find a free vnode slot in the vnode table */    
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  struct vnode *vp;
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  for (vp = &vnode[0]; vp < &vnode[NR_VNODES]; ++vp)
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	if (vp->v_ref_count == 0)
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	{
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		vp->v_pipe= NO_PIPE;
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		vp->v_uid= -1;
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		vp->v_gid= -1;
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		vp->v_sdev= -1;
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		vp->v_file= file;
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		vp->v_line= line;
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		return vp;
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	}
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  err_code = ENFILE;
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  return NIL_VNODE;
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}
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/*===========================================================================*
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 *				find_vnode				     *
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 *===========================================================================*/
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PUBLIC struct vnode *find_vnode(int fs_e, int numb)
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{
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/* Find a specified (FS endpoint and inode number) vnode in the
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 * vnode table */
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  struct vnode *vp;
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  for (vp = &vnode[0]; vp < &vnode[NR_VNODES]; ++vp)
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      if (vp->v_ref_count > 0 && vp->v_inode_nr == numb
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              && vp->v_fs_e == fs_e) return vp;
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  return NIL_VNODE;
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}
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/*===========================================================================*
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 *				dup_vnode				     *
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 *===========================================================================*/
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PUBLIC void dup_vnode(struct vnode *vp)
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{
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/* dup_vnode() is called to increment the vnode and therefore the
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 * referred inode's counter.
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 */
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  if (vp == NIL_VNODE) {
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      printf("VFSdup_vnode NIL_VNODE\n");
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      return;
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  }
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  vp->v_ref_count++;
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}
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/*===========================================================================*
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 *				put_vnode				     *
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 *===========================================================================*/
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PUBLIC void put_vnode(struct vnode *vp)
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{
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/* Decrease vnode's usage counter and decrease inode's usage counter in the 
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 * corresponding FS process.
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 */
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  if (vp == NIL_VNODE) {
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        /*printf("VFSput_vnode NIL_VNODE\n");*/
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        return;
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  }
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  if (vp < &vnode[0] || vp >= &vnode[NR_VNODES])
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  {
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	printf("put_vnode: &vnode[0] = %p, &vnode[NR_VNODES] = %p, vp = %p\n",
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		&vnode[0], &vnode[NR_VNODES], vp);
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	panic(__FILE__, "put_vnode: bad vnode pointer", NO_NUM);
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  }
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  if (vp->v_ref_count > 1)
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  {
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	/* Decrease counter */
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	vp->v_ref_count--;
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	if (vp->v_fs_count > 256)
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		vnode_clean_refs(vp);
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	return;
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  }
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  if (vp->v_ref_count <= 0)
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  {
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	printf("put_vnode: bad v_ref_count %d\n", vp->v_ref_count);
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	panic(__FILE__, "put_vnode failed", NO_NUM);
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  }
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  if (vp->v_fs_count <= 0)
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  {
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	printf("put_vnode: bad v_fs_count %d\n", vp->v_fs_count);
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	panic(__FILE__, "put_vnode failed", NO_NUM);
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  }
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  /* Send request */
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  if (req_putnode(vp->v_fs_e, vp->v_inode_nr, vp->v_fs_count) != OK)
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      printf("VFSput_vnode Warning: inode doesn't exist\n"); 
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  vp->v_fs_count= 0;
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  vp->v_ref_count= 0;
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  vp->v_pipe = NO_PIPE;
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  vp->v_sdev = NO_DEV;
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  vp->v_index = 0;
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}
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/*===========================================================================*
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 *				vnode_clean_refs			     *
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 *===========================================================================*/
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PUBLIC void vnode_clean_refs(struct vnode *vp)
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{
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/* Tell the underlying FS to drop all reference but one. */
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  if (vp == NIL_VNODE) {
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        return;
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  }
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  if (vp->v_fs_count <= 1)
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	return;	/* Nothing to do */
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  if (req_putnode(vp->v_fs_e, vp->v_inode_nr, vp->v_fs_count-1) != OK)
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	printf("vnode_clean_refs: req_putnode failed\n"); 
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  vp->v_fs_count= 1;
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}
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#if 0
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/*===========================================================================*
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 *				mark_vn					     *
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 *===========================================================================*/
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PUBLIC void mark_vn(vp, file, line)
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struct vnode *vp;
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char *file;
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int line;
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{
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	if (!vp)
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		return;
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	vp->v_file= file;
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	vp->v_line= line;
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}
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/*===========================================================================*
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 *				check_vrefs				     *
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 *===========================================================================*/
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PUBLIC int check_vrefs()
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{
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	int i, bad;
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	int ispipe_flag, ispipe_mode;
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	struct vnode *vp;
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	struct vmnt *vmp;
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	struct fproc *rfp;
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	struct filp *f;
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	/* Clear v_ref_check */
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	for (vp = &vnode[0]; vp < &vnode[NR_VNODES]; ++vp)
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		vp->v_ref_check= 0;
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	/* Count reference for processes */
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	for (rfp=&fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
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		if (rfp->fp_pid == PID_FREE)
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			continue;
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		vp= rfp->fp_rd;
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		if (vp < &vnode[0] || vp >= &vnode[NR_VNODES])
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			panic(__FILE__, "check_vrefs: bad vnode", NO_NUM);
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		vp->v_ref_check++;
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                vp= rfp->fp_wd;
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		if (vp < &vnode[0] || vp >= &vnode[NR_VNODES])
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			panic(__FILE__, "check_vrefs: bad vnode", NO_NUM);
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		vp->v_ref_check++;
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  	}
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	/* Count references from filedescriptors */
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	for (f = &filp[0]; f < &filp[NR_FILPS]; f++)
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	{
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		if (f->filp_count == 0)
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			continue;
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		vp= f->filp_vno;
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		if (vp < &vnode[0] || vp >= &vnode[NR_VNODES])
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			panic(__FILE__, "check_vrefs: bad vnode", NO_NUM);
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		vp->v_ref_check++;
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	}
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	/* Count references to mount points */
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	for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp)
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	{
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		if (vmp->m_dev == NO_DEV)
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			continue;
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		vp= vmp->m_mounted_on;
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		if (vp < &vnode[0] || vp >= &vnode[NR_VNODES])
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			panic(__FILE__, "check_vrefs: bad vnode", NO_NUM);
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		vp->v_ref_check++;
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		vp= vmp->m_root_node;
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		if (vp < &vnode[0] || vp >= &vnode[NR_VNODES])
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			panic(__FILE__, "check_vrefs: bad vnode", NO_NUM);
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		vp->v_ref_check++;
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	}
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	/* Check references */
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	bad= 0;
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	for (vp = &vnode[0]; vp < &vnode[NR_VNODES]; ++vp)
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	{
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		if (vp->v_ref_count != vp->v_ref_check)
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		{
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			printf(
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"Bad reference count for inode %d on device 0x%x: found %d, listed %d\n",
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				vp->v_inode_nr, vp->v_dev, vp->v_ref_check,
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				vp->v_ref_count);
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			printf("last marked at %s, %d\n",
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				vp->v_file, vp->v_line);
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			bad= 1;
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		}
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		/* Also check v_pipe */
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		if (vp->v_ref_count != 0)
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		{
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			ispipe_flag= (vp->v_pipe == I_PIPE);
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			ispipe_mode= ((vp->v_mode & I_TYPE) == I_NAMED_PIPE);
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			if (ispipe_flag != ispipe_mode)
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			{
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				printf(
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"Bad v_pipe for inode %d on device 0x%x: found %d, mode 0%o\n",
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				vp->v_inode_nr, vp->v_dev, vp->v_pipe,
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				vp->v_mode);
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				printf("last marked at %s, %d\n",
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					vp->v_file, vp->v_line);
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				bad= 1;
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			}
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		}
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	}
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	return !bad;
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}
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#endif
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