Re: Linux 2.4.10-pre11

[Andrea Arcangeli]

On Thu, Sep 20, 2001 at 06:52:07AM -0400, Alexander Viro wrote:
> 
> 
> On Thu, 20 Sep 2001, Andrea Arcangeli wrote:
> 
> > On Wed, Sep 19, 2001 at 03:21:09PM -0400, Alexander Viro wrote:
> > > int fd = open("/dev/ram0", O_RDWR);
> > > ioctl(fd, BLKFLSBUF);
> > > ioctl(fd, BLKFLSBUF);
> > 
> > here it is the fix below.
> [snip]
> > @@ -328,8 +369,16 @@
> >  				bdev->bd_openers--;
> >  				bdev->bd_cache_openers--;
> >  				iput(rd_inode[minor]);
> > +				/*
> > +				 * Make sure the cache is flushed from here
> > +				 * and not from close(2), somebody
> > +				 * could reopen the device before we have a
> > +				 * chance to close it ourself.
> > +				 */
> > +				truncate_inode_pages(rd_inode[minor]->i_mapping, 0);
> >  				rd_inode[minor] = NULL;
> >  				rd_blocksizes[minor] = rd_blocksize;
> > +			unlock:
> >  				up(&bdev->bd_sem);
> 
> Now think what happens if you go through that code twice.  What argument will
> be passed to iput() the second time you call it?

the second time we won't go through that code.

Andrea