Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into s…

…taging

Block layer patches:

- qcow2: Fix potential corruption for preallocated resize with external data file

# gpg: Signature made Tue 16 Apr 2019 15:23:35 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  qcow2: Fix preallocation bdrv_pwrite to wrong file

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

block/qcow2.c

@@ -2723,6 +2723,7 @@ static int qcow2_set_up_encryption(BlockDriverState *bs,
 static int coroutine_fn preallocate_co(BlockDriverState *bs, uint64_t offset,
                                        uint64_t new_length)
 {
+    BDRVQcow2State *s = bs->opaque;
     uint64_t bytes;
     uint64_t host_offset = 0;
     unsigned int cur_bytes;
@@ -2771,7 +2772,7 @@ static int coroutine_fn preallocate_co(BlockDriverState *bs, uint64_t offset,
      */
     if (host_offset != 0) {
         uint8_t data = 0;
-        ret = bdrv_pwrite(bs->file, (host_offset + cur_bytes) - 1,
+        ret = bdrv_pwrite(s->data_file, (host_offset + cur_bytes) - 1,
                           &data, 1);
         if (ret < 0) {
             return ret;