On 28/02/11 09:28, Pádraig Brady wrote:
> I just noticed that dd may discard read data
> in the presence of I/O errors.
> Would something like this suffice?
>
> cheers,
> Pádraig.
>
> diff --git a/src/dd.c b/src/dd.c
> index 1a0e177..a1d47ff 100644
> --- a/src/dd.c
> +++ b/src/dd.c
> @@ -811,12 +811,28 @@ static ssize_t
> iread_fullblock (int fd, char *buf, size_t size)
> {
> ssize_t nread = 0;
> + static iread_errno;
> +
> + /* Return a pending error. */
> + if (iread_errno)
> + {
> + errno = iread_errno;
> + iread_errno = 0;
> + return -1;
> + }
>
> while (0 < size)
> {
> ssize_t ncurr = iread (fd, buf, size);
> if (ncurr < 0)
> - return ncurr;
> + {
> + if (nread > 0)
> + {
> + iread_errno = errno;
> + ncurr = nread;
> + }
> + return ncurr;
> + }
> if (ncurr == 0)
> break;
> nread += ncurr;
Hmm, this issue is largely theoretical as we won't
be getting short reads from files in the first place
where we could get EIO.
I'll leave this for the moment
