From patchwork Sun May 16 11:59:57 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: block: fix aio_flush segfaults for read-only protocols (e.g. curl) Date: Sun, 16 May 2010 01:59:57 -0000 From: Avi Kivity X-Patchwork-Id: 52743 Message-Id: <1274011197-26196-1-git-send-email-avi@redhat.com> To: Kevin Wolf Cc: qemu-devel@nongnu.org Not all block format drivers expose an io_flush method (reasonable for read-only protocols), so calling io_flush there will immediately segfault. Fix by checking for the method's existence before calling it. Signed-off-by: Avi Kivity Reviewed-by: Christoph Hellwig --- aio.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/aio.c b/aio.c index f164a47..2f08655 100644 --- a/aio.c +++ b/aio.c @@ -113,7 +113,9 @@ void qemu_aio_flush(void) qemu_aio_wait(); QLIST_FOREACH(node, &aio_handlers, node) { - ret |= node->io_flush(node->opaque); + if (node->io_flush) { + ret |= node->io_flush(node->opaque); + } } } while (qemu_bh_poll() || ret > 0); }