Re: [PATCH] ufs: Check if page has buffers before callingpage_buffers()

[Evgeniy Dushistov]

On Tue, Feb 01, 2011 at 10:23:38PM +0100, Alessio Igor Bogani wrote:
> In ufs_change_blocknr() we have called page_buffers() without checking if the
> page actually had pages attached to it and this could cause a BUG oops.
> 

This looks wrong for me. May be I missed something?
Put little more context here.
In ufs the tail of small files consists of fragments (usually 2K),
the rest of file consists of blocks (usually 16K=8 fragments).
When file is growing, and tail become too big (8 fragments)
we allocate one block and move content of 8 fragments to it.

So in our case we reach (during realocation) point when
!page_has_buffers(page) (how?) and in your patch you suggest
just ignore such buffer (in terms of ufs - fragments),
in other words silently corrupt user data.
May be there is better variant?


-- 
/Evgeniy

--
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/