[Qemu-devel] [PATCH] qcow2: Fix error handling for reading compressed clusters

[Kevin Wolf <kwolf@redhat.com>]

When reading a compressed cluster failed, qcow2 falsely returned success.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-cluster.c |    4 ++--
 block/qcow2.c         |    4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 5fb8c66..437aaa8 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -878,11 +878,11 @@ int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
         BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
         ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data, nb_csectors);
         if (ret < 0) {
-            return -1;
+            return ret;
         }
         if (decompress_buffer(s->cluster_cache, s->cluster_size,
                               s->cluster_data + sector_offset, csize) < 0) {
-            return -1;
+            return -EIO;
         }
         s->cluster_cache_offset = coffset;
     }
diff --git a/block/qcow2.c b/block/qcow2.c
index 647c2a4..551b3c2 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -497,8 +497,10 @@ static void qcow2_aio_read_cb(void *opaque, int ret)
         }
     } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
         /* add AIO support for compressed blocks ? */
-        if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0)
+        ret = qcow2_decompress_cluster(bs, acb->cluster_offset);
+        if (ret < 0) {
             goto done;
+        }
 
         qemu_iovec_from_buffer(&acb->hd_qiov,
             s->cluster_cache + index_in_cluster * 512,
-- 
1.7.2.3