Re: [PATCH] fs: make block fiemap mapping length at least blocksize long

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

Is there any reason this cannot be sent to Linus now?

Steve.

On Wed, 2010-12-08 at 12:03 -0500, Josef Bacik wrote:
> Some filesystems don't deal well with being asked to map less than blocksize
> blocks (GFS2 for example).  Since we are always mapping at least blocksize
> sections anyway, just make sure len is at least as big as a blocksize so we
> don't trip up any filesystems.  Thanks,
> 
> Signed-off-by: Josef Bacik <josef@redhat.com>
> ---
>  fs/ioctl.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ioctl.c b/fs/ioctl.c
> index d6cc164..6b53c24 100644
> --- a/fs/ioctl.c
> +++ b/fs/ioctl.c
> @@ -273,6 +273,13 @@ int __generic_block_fiemap(struct inode *inode,
>  		len = isize;
>  	}
>  
> +	/*
> +	 * Some filesystems can't deal with being asked to map less than
> +	 * blocksize, so make sure our len is at least block length.
> +	 */
> +	if (logical_to_blk(inode, len) == 0)
> +		len = blk_to_logical(inode, 1);
> +
>  	start_blk = logical_to_blk(inode, start);
>  	last_blk = logical_to_blk(inode, start + len - 1);
>