Re: [Patch] fs: remove a useless BUG()

[Marcin Slusarz <marcin.slusarz@gmail.com>]

On Mon, Nov 30, 2009 at 09:34:14PM -0500, Amerigo Wang wrote:
> This BUG() is suspicious, it makes its following statements
> unreachable, 
only when CONFIG_BUG=y

> and it seems to be useless, since the caller
> of this function already handles the failure properly.
because this function can return NULL in other codepath

> Remove it.
I don't know why this BUG() is there (and maybe it's not really
needed), but your rationale is wrong.

> Signed-off-by: WANG Cong <amwang@redhat.com>
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: Jens Axboe <jens.axboe@oracle.com>
> Cc: Nick Piggin <npiggin@suse.de>
> Cc: "Theodore Ts'o" <tytso@mit.edu>
> 
> ---
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 6fa5302..ac111d7 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -1041,7 +1041,6 @@ grow_dev_page(struct block_device *bdev, sector_t block,
>  	return page;
>  
>  failed:
> -	BUG();
>  	unlock_page(page);
>  	page_cache_release(page);
>  	return NULL;
> --