From: =?UTF-8?q?Jind=C5=99ich=20Makovi=C4=8Dka?= Date: Wed, 24 Jun 2015 07:05:25 +0200 Subject: [PATCH] qcow2: Handle EAGAIN returned from update_refcount MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes a crash during image compression Signed-off-by: Jindřich Makovička Tested-by: Richard W.M. Jones Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi (cherry picked from commit 3e5feb6202149e8a963a33b911216e40d790f1d7) --- block/qcow2-refcount.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 63c0085..d4f3351 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -954,19 +954,21 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) } free_in_cluster = s->cluster_size - offset_into_cluster(s, offset); - if (!offset || free_in_cluster < size) { - int64_t new_cluster = alloc_clusters_noref(bs, s->cluster_size); - if (new_cluster < 0) { - return new_cluster; - } + do { + if (!offset || free_in_cluster < size) { + int64_t new_cluster = alloc_clusters_noref(bs, s->cluster_size); + if (new_cluster < 0) { + return new_cluster; + } - if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) { - offset = new_cluster; + if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) { + offset = new_cluster; + } } - } - assert(offset); - ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); + assert(offset); + ret = update_refcount(bs, offset, size, 1, false, QCOW2_DISCARD_NEVER); + } while (ret == -EAGAIN); if (ret < 0) { return ret; }