From 4baaa8c3d891b57036fd2a7c6a890737793fe3a0 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 7 Dec 2016 16:08:27 +0100 Subject: [PATCH] qemu-img: fix in-flight count for qemu-img bench 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 6949b73ca5..5df66fe661 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; } } -- GitLab