Re: [PATCH 01/14] ide-tape: fix potential fs requests bug

Sam Ravnborg
2009-05-09T08:00:44Z

On Sat, May 09, 2009 at 09:45:21AM +0200, Borislav Petkov wrote:
> ide-tape had a potential bug for fs requests when preparing the command
> packet: it was writing the transfer length as a number of fixed blocks.
> However, the block layer implies 512 byte blocks and ide-tape can have
> other block sizes so account for that too.
>
> ide-floppy does this calculation properly with the block size factor
> (floppy->bs_factor).
>
> Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
> ---
> drivers/ide/ide-tape.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
> index e166045..fc79cf4 100644
> --- a/drivers/ide/ide-tape.c
> +++ b/drivers/ide/ide-tape.c
> @@ -586,7 +586,7 @@ static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
> struct ide_atapi_pc *pc, struct request *rq,
> u8 opcode)
> {
> - unsigned int length = blk_rq_sectors(rq);
> + unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);

If tape->blk_size equals 256 or less then we get a divide-by-zero.

Sam