On Fri, Mar 05, 2010 at 11:20:38PM -0500, Laine Stump wrote:
> doTunnelSendAll function (used by QEMU migration) uses a 64k buffer on
> the stack, which could be problematic. This patch replaces that with a
> buffer from the heap.
>
> While in the neighborhood, this patch also improves error reporting in
> the case that saferead fails - previously, virStreamAbort() was called
> (resetting errno) before reporting the error. It's been changed to
> report the error first.
> ---
>
> Eric noticed that I was inconsistent in the ordering of cleanup
> vs. error reporting, so I fixed that in this version.
>
> src/qemu/qemu_driver.c | 18 +++++++++++++++---
> 1 files changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index bb3edde..5a18938 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -8399,19 +8399,28 @@ cleanup:
> }
>
>
> +#define TUNNEL_SEND_BUF_SIZE 65536
> +
> static int doTunnelSendAll(virStreamPtr st,
> int sock)
> {
> - char buffer[65536];
> - int nbytes = sizeof(buffer);
> + char *buffer;
> + int nbytes = TUNNEL_SEND_BUF_SIZE;
> +
> + if (VIR_ALLOC_N(buffer, TUNNEL_SEND_BUF_SIZE) < 0) {
> + virReportOOMError();
> + virStreamAbort(st);
> + return -1;
> + }
>
> /* XXX should honour the 'resource' parameter here */
> for (;;) {
> nbytes = saferead(sock, buffer, nbytes);
> if (nbytes < 0) {
> - virStreamAbort(st);
> virReportSystemError(errno, "%s",
> _("tunnelled migration failed to read from qemu"));
> + virStreamAbort(st);
> + VIR_FREE(buffer);
> return -1;
> }
> else if (nbytes == 0)
> @@ -8421,10 +8430,13 @@ static int doTunnelSendAll(virStreamPtr st,
> if (virStreamSend(st, buffer, nbytes) < 0) {
> qemuReportError(VIR_ERR_OPERATION_FAILED, "%s",
> _("Failed to write migration data to remote libvirtd"));
> + VIR_FREE(buffer);
> return -1;
> }
> }
>
> + VIR_FREE(buffer);
> +
> if (virStreamFinish(st) < 0)
> /* virStreamFinish set the error for us */
> return -1;
ACK, that needed to be fixed !
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel@xxxxxxxxxxxx | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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