From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33315) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cQaFn-0006hA-Kd for qemu-devel@nongnu.org; Mon, 09 Jan 2017 08:44:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cQaFm-0002yc-I7 for qemu-devel@nongnu.org; Mon, 09 Jan 2017 08:44:51 -0500 From: Kevin Wolf Date: Mon, 9 Jan 2017 14:44:23 +0100 Message-Id: <1483969476-7172-2-git-send-email-kwolf@redhat.com> In-Reply-To: <1483969476-7172-1-git-send-email-kwolf@redhat.com> References: <1483969476-7172-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 01/14] qemu-img: fix in-flight count for qemu-img bench List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Paolo Bonzini With aio=native (qemu-img bench -n) one or more requests can be completed when a new request is submitted. This in turn can cause bench_cb to recurse before b->in_flight is updated. This causes multiple I/Os to be submitted with the same offset and, furthermore, the blk_aio_* coroutines are never freed and qemu-img aborts. Signed-off-by: Paolo Bonzini Reviewed-by: John Snow Signed-off-by: Kevin Wolf --- qemu-img.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 6949b73..5df66fe 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3559,20 +3559,23 @@ static void bench_cb(void *opaque, int ret) } while (b->n > b->in_flight && b->in_flight < b->nrreq) { + int64_t offset = b->offset; + /* blk_aio_* might look for completed I/Os and kick bench_cb + * again, so make sure this operation is counted by in_flight + * and b->offset is ready for the next submission. + */ + b->in_flight++; + b->offset += b->step; + b->offset %= b->image_size; if (b->write) { - acb = blk_aio_pwritev(b->blk, b->offset, b->qiov, 0, - bench_cb, b); + acb = blk_aio_pwritev(b->blk, offset, b->qiov, 0, bench_cb, b); } else { - acb = blk_aio_preadv(b->blk, b->offset, b->qiov, 0, - bench_cb, b); + acb = blk_aio_preadv(b->blk, offset, b->qiov, 0, bench_cb, b); } if (!acb) { error_report("Failed to issue request"); exit(EXIT_FAILURE); } - b->in_flight++; - b->offset += b->step; - b->offset %= b->image_size; } } -- 1.8.3.1