Re: [PATCH] Reiser4 bug fixes

[Christoph Hellwig <hch@infradead.org>]

On Wed, Jul 19, 2006 at 01:22:23PM -0700, Hans Reiser wrote:
> Hopefully this will make reiser4 stable code again.  Or at least, a lot more stable than v3 (or other FSes) was when it went in....
> 
> 
> Signed-off-by: Hans Reiser
> 
> From: Vladimir Saveliev <vs@namesys.com>
> 
> This patch contains 4 reiser4 bug fixes:
> - missing long term lock unlock on read' error handling code path is added
> - truncate_inode_pages is now called with embedded mapping. 
>   It is needed to deal properly with block device special files.
> - copy_to_user might be called for more bytes than was prefaulted with fault_in_pages_writeable.
>   That caused undesirable major page faults.
> - readdir bug similar to the previous one:
>   call to filldir might lead to deadlock due to major page fault.
> 
> Signed-off-by: Vladimir Saveliev <vs@namesys.com>
> 
> 
> 
> diff -puN fs/reiser4/super_ops.c~reiser4-one-line-fixes fs/reiser4/super_ops.c
> --- linux-2.6.18-rc-mm2/fs/reiser4/super_ops.c~reiser4-one-line-fixes	2006-07-19 16:25:49.000000000 +0400
> +++ linux-2.6.18-rc-mm2-vs/fs/reiser4/super_ops.c	2006-07-19 16:25:49.000000000 +0400
> @@ -202,7 +202,7 @@ static void reiser4_delete_inode(struct 
>  			fplug->delete_object(inode);
>  	}
>  
> -	truncate_inode_pages(inode->i_mapping, 0);
> +	truncate_inode_pages(&inode->i_data, 0);

Where do you reset i_mapping to be different from i_data?  It is a valid
thing to do in theory (that's why we have those different fields), but in
practice most usages I've seen are bogus.

(And yes, this is not a personal attack again you, just a normal review)