Re: [Patch 1/2] tabled: fix bugs in streaming of data

[Jeff Garzik <jeff@garzik.org>]

On 01/05/2010 02:27 AM, Pete Zaitcev wrote:
> This patch fixes 3 plain coding bugs in the streaming mechanism.
>
> 1. Whenever we loop back to "restart" label, we have to clear n_iov.
>     Otherwise, the loop that fills iov[] writes beyond the end of the
>     array. The result is binary garbage on console and a hang.
>
>     Behold the evils of initialized variables. Fix is obvious.
>
>     BTW, array indexes are signed.
>
> 2. When we consume a queue element partially, we ought to advance its
>     buffer pointer when we decrement the length. Otherwise, we resend
>     the data that was sent already, causing a corruption in transfer.
>
>     The fix is obvious (add tmp->buf += sz).
>
> 3. The accounting (through unfortunately named write_cnt) was incorrect
>     because wr->len may be decremented by the time the element is freed.
>
> Since we're at it, we implement a couple of safety improvements.
> First, we change the API to the callback a little. From now on, it
> does not have access to the struct client_write anymore, and cannot
> accidentially rely on wr->buf (which can be changed now).
> Also, we renamed "len" into "togo" and named the new member "length",
> to make sure that all use instances for "len" were reviewed.
>
> Signed-Off-By: Pete Zaitcev<zaitcev@redhat.com>
>
> ---
>   server/object.c |    8 +++-----
>   server/server.c |   31 ++++++++++++++++---------------
>   server/tabled.h |   11 ++++++-----
>   3 files changed, 25 insertions(+), 25 deletions(-)

applied...  chunkd needs these fixes also, yes?