Re: [RFC] get_write_access()/deny_write_access() withoutinode->i_lock

[Al Viro]

On Mon, Jun 20, 2011 at 01:47:17PM +0100, David Howells wrote:
> Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
> 
> > +	for (v = atomic_read(&inode->i_writecount); v >= 0; v = v1) {
> > +		v1 = atomic_cmpxchg(&inode->i_writecount, v, v + 1);
> > +		if (likely(v1 == v))
> > +			return 0;
> > +	}
> 
> You don't need to reissue the atomic_read().  atomic_cmpxchg() returns the
> current value of the memory location.  Just set v to v1 before going round the
> loop again.

That's precisely what that loop is doing...
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/