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

Block layer patches:

- qemu-img convert -C is now required to enable copy offloading
- file-posix: Fix write_zeroes with unmap on block devices (would fall
  back to explicit writes on recent kernels)
- Fix query-blockstats interface for use with -blockdev
- Minor fixes and documentation updates

# gpg: Signature made Mon 30 Jul 2018 16:08:14 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  qemu-iotests: Test query-blockstats with -drive and -blockdev
  block/qapi: Include anonymous BBs in query-blockstats
  block/qapi: Add 'qdev' field to query-blockstats result
  file-posix: Fix write_zeroes with unmap on block devices
  block: Fix documentation for BDRV_REQ_MAY_UNMAP
  iotests: Add test for 'qemu-img convert -C' compatibility
  qemu-img: Add -C option for convert with copy offloading
  Revert "qemu-img: Document copy offloading implications with -S and -c"
  iotests: Don't lock /dev/null in 226
  docs: Describe using images in writing iotests
  file-posix: Handle EINTR in preallocation=full write
  qcow2: A grammar fix in conflicting cache sizing error message
  qcow: fix a reference leak

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

18 files changed, 449 insertions, 41 deletions

diff --git a/block/file-posix.c b/block/file-posix.c
index ad299be..fe83cbf 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -648,7 +648,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
     }
 #endif
 
-    bs->supported_zero_flags = s->discard_zeroes ? BDRV_REQ_MAY_UNMAP : 0;
+    bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
     ret = 0;
 fail:
     if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
@@ -1487,6 +1487,35 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
     return -ENOTSUP;
 }
 
+static ssize_t handle_aiocb_write_zeroes_unmap(RawPosixAIOData *aiocb)
+{
+    BDRVRawState *s G_GNUC_UNUSED = aiocb->bs->opaque;
+    int ret;
+
+    /* First try to write zeros and unmap at the same time */
+
+#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+    ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+                       aiocb->aio_offset, aiocb->aio_nbytes);
+    if (ret != -ENOTSUP) {
+        return ret;
+    }
+#endif
+
+#ifdef CONFIG_XFS
+    if (s->is_xfs) {
+        /* xfs_discard() guarantees that the discarded area reads as all-zero
+         * afterwards, so we can use it here. */
+        return xfs_discard(s, aiocb->aio_offset, aiocb->aio_nbytes);
+    }
+#endif
+
+    /* If we couldn't manage to unmap while guaranteed that the area reads as
+     * all-zero afterwards, just write zeroes without unmapping */
+    ret = handle_aiocb_write_zeroes(aiocb);
+    return ret;
+}
+
 #ifndef HAVE_COPY_FILE_RANGE
 static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
                              off_t *out_off, size_t len, unsigned int flags)
@@ -1646,6 +1675,9 @@ static int handle_aiocb_truncate(RawPosixAIOData *aiocb)
             num = MIN(left, 65536);
             result = write(fd, buf, num);
             if (result < 0) {
+                if (errno == EINTR) {
+                    continue;
+                }
                 result = -errno;
                 error_setg_errno(errp, -result,
                                  "Could not write zeros for preallocation");
@@ -1729,6 +1761,9 @@ static int aio_worker(void *arg)
     case QEMU_AIO_WRITE_ZEROES:
         ret = handle_aiocb_write_zeroes(aiocb);
         break;
+    case QEMU_AIO_WRITE_ZEROES | QEMU_AIO_DISCARD:
+        ret = handle_aiocb_write_zeroes_unmap(aiocb);
+        break;
     case QEMU_AIO_COPY_RANGE:
         ret = handle_aiocb_copy_range(aiocb);
         break;
@@ -2553,15 +2588,13 @@ static int coroutine_fn raw_co_pwrite_zeroes(
     int bytes, BdrvRequestFlags flags)
 {
     BDRVRawState *s = bs->opaque;
+    int operation = QEMU_AIO_WRITE_ZEROES;
 
-    if (!(flags & BDRV_REQ_MAY_UNMAP)) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_WRITE_ZEROES);
-    } else if (s->discard_zeroes) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_DISCARD);
+    if (flags & BDRV_REQ_MAY_UNMAP) {
+        operation |= QEMU_AIO_DISCARD;
     }
-    return -ENOTSUP;
+
+    return paio_submit_co(bs, s->fd, offset, NULL, bytes, operation);
 }
 
 static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
@@ -3054,20 +3087,19 @@ static coroutine_fn int hdev_co_pwrite_zeroes(BlockDriverState *bs,
     int64_t offset, int bytes, BdrvRequestFlags flags)
 {
     BDRVRawState *s = bs->opaque;
+    int operation = QEMU_AIO_WRITE_ZEROES | QEMU_AIO_BLKDEV;
     int rc;
 
     rc = fd_open(bs);
     if (rc < 0) {
         return rc;
     }
-    if (!(flags & BDRV_REQ_MAY_UNMAP)) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_WRITE_ZEROES|QEMU_AIO_BLKDEV);
-    } else if (s->discard_zeroes) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_DISCARD|QEMU_AIO_BLKDEV);
+
+    if (flags & BDRV_REQ_MAY_UNMAP) {
+        operation |= QEMU_AIO_DISCARD;
     }
-    return -ENOTSUP;
+
+    return paio_submit_co(bs, s->fd, offset, NULL, bytes, operation);
 }
 
 static int coroutine_fn hdev_co_create_opts(const char *filename, QemuOpts *opts,
diff --git a/block/qapi.c b/block/qapi.c
index e12968f..339727f 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -593,15 +593,29 @@ BlockStatsList *qmp_query_blockstats(bool has_query_nodes,
             p_next = &info->next;
         }
     } else {
-        for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
+        for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) {
             BlockStatsList *info = g_malloc0(sizeof(*info));
             AioContext *ctx = blk_get_aio_context(blk);
             BlockStats *s;
+            char *qdev;
+
+            if (!*blk_name(blk) && !blk_get_attached_dev(blk)) {
+                continue;
+            }
 
             aio_context_acquire(ctx);
             s = bdrv_query_bds_stats(blk_bs(blk), true);
             s->has_device = true;
             s->device = g_strdup(blk_name(blk));
+
+            qdev = blk_get_attached_dev_id(blk);
+            if (qdev && *qdev) {
+                s->has_qdev = true;
+                s->qdev = qdev;
+            } else {
+                g_free(qdev);
+            }
+
             bdrv_query_blk_stats(s->stats, blk);
             aio_context_release(ctx);
 
diff --git a/block/qcow.c b/block/qcow.c
index 102d058..385d935 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -938,6 +938,7 @@ static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
     ret = 0;
 exit:
     blk_unref(qcow_blk);
+    bdrv_unref(bs);
     qcrypto_block_free(crypto);
     return ret;
 }
diff --git a/block/qcow2.c b/block/qcow2.c
index 6162ed8..ec9e623 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -797,7 +797,7 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
         if (l2_cache_size_set && refcount_cache_size_set) {
             error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE
                        " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set "
-                       "the same time");
+                       "at the same time");
             return;
         } else if (*l2_cache_size > combined_cache_size) {
             error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed "
diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
index 5e19cd5..8e1fa3a 100644
--- a/docs/devel/testing.rst
+++ b/docs/devel/testing.rst
@@ -255,6 +255,17 @@ comparable library support for invoking and interacting with QEMU programs. If
 you opt for Python, it is strongly recommended to write Python 3 compatible
 code.
 
+Both Python and Bash frameworks in iotests provide helpers to manage test
+images. They can be used to create and clean up images under the test
+directory. If no I/O or any protocol specific feature is needed, it is often
+more convenient to use the pseudo block driver, ``null-co://``, as the test
+image, which doesn't require image creation or cleaning up. Avoid system-wide
+devices or files whenever possible, such as ``/dev/null`` or ``/dev/zero``.
+Otherwise, image locking implications have to be considered.  For example,
+another application on the host may have locked the file, possibly leading to a
+test failure.  If using such devices are explicitly desired, consider adding
+``locking=off`` option to disable image locking.
+
 Docker based tests
 ==================
 
diff --git a/include/block/block.h b/include/block/block.h
index f85e3a6..4e0871a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -43,11 +43,12 @@ typedef struct BlockFragInfo {
 typedef enum {
     BDRV_REQ_COPY_ON_READ       = 0x1,
     BDRV_REQ_ZERO_WRITE         = 0x2,
-    /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
-     * is allowed to optimize a write zeroes request by unmapping (discarding)
-     * blocks if it is guaranteed that the result will read back as
-     * zeroes. The flag is only passed to the driver if the block device is
-     * opened with BDRV_O_UNMAP.
+
+    /*
+     * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
+     * that the block driver should unmap (discard) blocks if it is guaranteed
+     * that the result will read back as zeroes. The flag is only passed to the
+     * driver if the block device is opened with BDRV_O_UNMAP.
      */
     BDRV_REQ_MAY_UNMAP          = 0x4,
 
diff --git a/qapi/block-core.json b/qapi/block-core.json
index d40d5ec..5b9084a 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -866,6 +866,9 @@
 #
 # @node-name: The node name of the device. (Since 2.3)
 #
+# @qdev: The qdev ID, or if no ID is assigned, the QOM path of the block
+#        device. (since 3.0)
+#
 # @stats:  A @BlockDeviceStats for the device.
 #
 # @parent: This describes the file block device if it has one.
@@ -879,7 +882,7 @@
 # Since: 0.14.0
 ##
 { 'struct': 'BlockStats',
-  'data': {'*device': 'str', '*node-name': 'str',
+  'data': {'*device': 'str', '*qdev': 'str', '*node-name': 'str',
            'stats': 'BlockDeviceStats',
            '*parent': 'BlockStats',
            '*backing': 'BlockStats'} }
@@ -941,7 +944,8 @@
 #                "idle_time_ns":2953431879,
 #                "account_invalid":true,
 #                "account_failed":false
-#             }
+#             },
+#             "qdev": "/machine/unattached/device[23]"
 #          },
 #          {
 #             "device":"ide1-cd0",
@@ -959,7 +963,8 @@
 #                "wr_merged":0,
 #                "account_invalid":false,
 #                "account_failed":false
-#             }
+#             },
+#             "qdev": "/machine/unattached/device[24]"
 #          },
 #          {
 #             "device":"floppy0",
@@ -977,7 +982,8 @@
 #                "wr_merged":0,
 #                "account_invalid":false,
 #                "account_failed":false
-#             }
+#             },
+#             "qdev": "/machine/unattached/device[16]"
 #          },
 #          {
 #             "device":"sd0",
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 69758fb..1526f32 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -44,7 +44,7 @@ STEXI
 ETEXI
 
 DEF("convert", img_convert,
-    "convert [--object objectdef] [--image-opts] [--target-image-opts] [-U] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] filename [filename2 [...]] output_filename")
+    "convert [--object objectdef] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] filename [filename2 [...]] output_filename")
 STEXI
 @item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}
 ETEXI
diff --git a/qemu-img.c b/qemu-img.c
index 9b7506b..1acddf6 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2024,11 +2024,12 @@ static int img_convert(int argc, char **argv)
          skip_create = false, progress = false, tgt_image_opts = false;
     int64_t ret = -EINVAL;
     bool force_share = false;
+    bool explict_min_sparse = false;
 
     ImgConvertState s = (ImgConvertState) {
         /* Need at least 4k of zeros for sparse detection */
         .min_sparse         = 8,
-        .copy_range         = true,
+        .copy_range         = false,
         .buf_sectors        = IO_BUF_SIZE / BDRV_SECTOR_SIZE,
         .wr_in_order        = true,
         .num_coroutines     = 8,
@@ -2043,7 +2044,7 @@ static int img_convert(int argc, char **argv)
             {"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},
             {0, 0, 0, 0}
         };
-        c = getopt_long(argc, argv, ":hf:O:B:co:l:S:pt:T:qnm:WU",
+        c = getopt_long(argc, argv, ":hf:O:B:Cco:l:S:pt:T:qnm:WU",
                         long_options, NULL);
         if (c == -1) {
             break;
@@ -2067,9 +2068,11 @@ static int img_convert(int argc, char **argv)
         case 'B':
             out_baseimg = optarg;
             break;
+        case 'C':
+            s.copy_range = true;
+            break;
         case 'c':
             s.compressed = true;
-            s.copy_range = false;
             break;
         case 'o':
             if (!is_valid_option_list(optarg)) {
@@ -2112,7 +2115,7 @@ static int img_convert(int argc, char **argv)
             }
 
             s.min_sparse = sval / BDRV_SECTOR_SIZE;
-            s.copy_range = false;
+            explict_min_sparse = true;
             break;
         }
         case 'p':
@@ -2172,6 +2175,16 @@ static int img_convert(int argc, char **argv)
         goto fail_getopt;
     }
 
+    if (s.compressed && s.copy_range) {
+        error_report("Cannot enable copy offloading when -c is used");
+        goto fail_getopt;
+    }
+
+    if (explict_min_sparse && s.copy_range) {
+        error_report("Cannot enable copy offloading when -S is used");
+        goto fail_getopt;
+    }
+
     if (tgt_image_opts && !skip_create) {
         error_report("--target-image-opts requires use of -n flag");
         goto fail_getopt;
diff --git a/qemu-img.texi b/qemu-img.texi
index 5853cd1..3b6710a 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -96,8 +96,7 @@ will enumerate information about backing files in a disk image chain. Refer
 below for further description.
 
 @item -c
-indicates that target image must be compressed (qcow format only). If this
-option is used, copy offloading will not be attempted.
+indicates that target image must be compressed (qcow format only)
 
 @item -h
 with or without a command shows help and lists the supported formats
@@ -116,8 +115,7 @@ in case both @var{-q} and @var{-p} options are used.
 indicates the consecutive number of bytes that must contain only zeros
 for qemu-img to create a sparse image during conversion. This value is rounded
 down to the nearest 512 bytes. You may use the common size suffixes like
-@code{k} for kilobytes. If this option is used, copy offloading will not be
-attempted.
+@code{k} for kilobytes.
 
 @item -t @var{cache}
 specifies the cache mode that should be used with the (destination) file. See
@@ -171,6 +169,12 @@ Number of parallel coroutines for the convert process
 Allow out-of-order writes to the destination. This option improves performance,
 but is only recommended for preallocated devices like host devices or other
 raw block devices.
+@item -C
+Try to use copy offloading to move data from source image to target. This may
+improve performance if the data is remote, such as with NFS or iSCSI backends,
+but will not automatically sparsify zero sectors, and may result in a fully
+allocated target image depending on the host support for getting allocation
+information.
 @end table
 
 Parameters to dd subcommand:
@@ -321,7 +325,7 @@ Error on reading data
 
 @end table
 
-@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}
+@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}
 
 Convert the disk image @var{filename} or a snapshot @var{snapshot_param}
 to disk image @var{output_filename} using format @var{output_fmt}. It can be optionally compressed (@code{-c}
diff --git a/tests/qemu-iotests/082 b/tests/qemu-iotests/082
index a872f77..3e605d5 100755
--- a/tests/qemu-iotests/082
+++ b/tests/qemu-iotests/082
@@ -158,6 +158,14 @@ run_qemu_img convert -o help
 run_qemu_img convert -O bochs -o help
 
 echo
+echo === convert: -C and other options ===
+
+# Adding the help option to a command without other -o options
+run_qemu_img convert -C -S 4k -O $IMGFMT "$TEST_IMG" "$TEST_IMG".target
+run_qemu_img convert -C -S 8k -O $IMGFMT "$TEST_IMG" "$TEST_IMG".target
+run_qemu_img convert -C -c -O $IMGFMT "$TEST_IMG" "$TEST_IMG".target
+
+echo
 echo === amend: Options specified more than once ===
 
 # Last -f should win
diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out
index 60ef87c..19e9fb1 100644
--- a/tests/qemu-iotests/082.out
+++ b/tests/qemu-iotests/082.out
@@ -508,6 +508,17 @@ size             Virtual disk size
 Testing: convert -O bochs -o help
 qemu-img: Format driver 'bochs' does not support image creation
 
+=== convert: -C and other options ===
+
+Testing: convert -C -S 4k -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
+qemu-img: Cannot enable copy offloading when -S is used
+
+Testing: convert -C -S 8k -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
+qemu-img: Cannot enable copy offloading when -S is used
+
+Testing: convert -C -c -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
+qemu-img: Cannot enable copy offloading when -c is used
+
 === amend: Options specified more than once ===
 
 Testing: amend -f foo -f qcow2 -o lazy_refcounts=on TEST_DIR/t.qcow2
diff --git a/tests/qemu-iotests/103.out b/tests/qemu-iotests/103.out
index bd45d38..bd9eec3 100644
--- a/tests/qemu-iotests/103.out
+++ b/tests/qemu-iotests/103.out
@@ -5,10 +5,10 @@ wrote 65536/65536 bytes at offset 0
 
 === Testing invalid option combinations ===
 
-can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
 can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
 can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
-can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
 can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
 can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
 can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
diff --git a/tests/qemu-iotests/137.out b/tests/qemu-iotests/137.out
index 96724a6..6a2ffc7 100644
--- a/tests/qemu-iotests/137.out
+++ b/tests/qemu-iotests/137.out
@@ -16,7 +16,7 @@ read 33554432/33554432 bytes at offset 0
 === Try setting some invalid values ===
 
 Parameter 'lazy-refcounts' expects 'on' or 'off'
-cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
 l2-cache-size may not exceed cache-size
 refcount-cache-size may not exceed cache-size
 L2 cache size too big
diff --git a/tests/qemu-iotests/226 b/tests/qemu-iotests/226
index 211ea98..8ec3e61 100755
--- a/tests/qemu-iotests/226
+++ b/tests/qemu-iotests/226
@@ -56,10 +56,10 @@ for PROTO in "file" "host_device" "host_cdrom"; do
     echo
     echo "== Testing RO =="
     $QEMU_IO -c "open -r -o driver=$PROTO,filename=$TEST_IMG" 2>&1 | _filter_testdir | _filter_imgfmt
-    $QEMU_IO -c "open -r -o driver=$PROTO,filename=/dev/null" 2>&1 | _filter_imgfmt
+    $QEMU_IO -c "open -r -o driver=$PROTO,filename=/dev/null,locking=off" 2>&1 | _filter_imgfmt
     echo "== Testing RW =="
     $QEMU_IO -c "open -o driver=$PROTO,filename=$TEST_IMG" 2>&1 | _filter_testdir | _filter_imgfmt
-    $QEMU_IO -c "open -o driver=$PROTO,filename=/dev/null" 2>&1 | _filter_imgfmt
+    $QEMU_IO -c "open -o driver=$PROTO,filename=/dev/null,locking=off" 2>&1 | _filter_imgfmt
 done
 
 # success, all done
diff --git a/tests/qemu-iotests/227 b/tests/qemu-iotests/227
new file mode 100755
index 0000000..9a5f7f9
--- /dev/null
+++ b/tests/qemu-iotests/227
@@ -0,0 +1,101 @@
+#!/bin/bash
+#
+# Test query-blockstats with different ways to create a BB
+#
+# Copyright (C) 2018 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=kwolf@redhat.com
+
+seq=$(basename $0)
+echo "QA output created by $seq"
+
+here=$PWD
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+_supported_fmt generic
+_supported_proto file
+_supported_os Linux
+
+function do_run_qemu()
+{
+    echo Testing: "$@"
+    $QEMU -nographic -qmp-pretty stdio -serial none "$@"
+    echo
+}
+
+function run_qemu()
+{
+    do_run_qemu "$@" 2>&1 | _filter_testdir | _filter_qmp \
+                          | _filter_qemu | _filter_imgfmt \
+                          | _filter_generated_node_ids
+}
+
+echo
+echo '=== blockstats with -drive if=virtio ==='
+echo
+
+run_qemu -drive driver=null-co,if=virtio <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+echo
+echo '=== blockstats with -drive if=none ==='
+echo
+
+run_qemu -drive driver=null-co,if=none <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+echo
+echo '=== blockstats with -blockdev ==='
+echo
+
+run_qemu -blockdev driver=null-co,node-name=null <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+echo
+echo '=== blockstats with -blockdev and -device ==='
+echo
+
+run_qemu -blockdev driver=null-co,node-name=null -device virtio-blk,drive=null,id=virtio0 <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/227.out b/tests/qemu-iotests/227.out
new file mode 100644
index 0000000..736f2e3
--- /dev/null
+++ b/tests/qemu-iotests/227.out
@@ -0,0 +1,205 @@
+QA output created by 227
+
+=== blockstats with -drive if=virtio ===
+
+Testing: -drive driver=null-co,if=virtio
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+        {
+            "device": "virtio0",
+            "stats": {
+                "flush_total_time_ns": 0,
+                "wr_highest_offset": 0,
+                "wr_total_time_ns": 0,
+                "failed_wr_operations": 0,
+                "failed_rd_operations": 0,
+                "wr_merged": 0,
+                "wr_bytes": 0,
+                "timed_stats": [
+                ],
+                "failed_flush_operations": 0,
+                "account_invalid": true,
+                "rd_total_time_ns": 0,
+                "flush_operations": 0,
+                "wr_operations": 0,
+                "rd_merged": 0,
+                "rd_bytes": 0,
+                "invalid_flush_operations": 0,
+                "account_failed": true,
+                "rd_operations": 0,
+                "invalid_wr_operations": 0,
+                "invalid_rd_operations": 0
+            },
+            "node-name": "NODE_NAME",
+            "qdev": "/machine/peripheral-anon/device[0]/virtio-backend"
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+
+=== blockstats with -drive if=none ===
+
+Testing: -drive driver=null-co,if=none
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+        {
+            "device": "none0",
+            "stats": {
+                "flush_total_time_ns": 0,
+                "wr_highest_offset": 0,
+                "wr_total_time_ns": 0,
+                "failed_wr_operations": 0,
+                "failed_rd_operations": 0,
+                "wr_merged": 0,
+                "wr_bytes": 0,
+                "timed_stats": [
+                ],
+                "failed_flush_operations": 0,
+                "account_invalid": true,
+                "rd_total_time_ns": 0,
+                "flush_operations": 0,
+                "wr_operations": 0,
+                "rd_merged": 0,
+                "rd_bytes": 0,
+                "invalid_flush_operations": 0,
+                "account_failed": true,
+                "rd_operations": 0,
+                "invalid_wr_operations": 0,
+                "invalid_rd_operations": 0
+            },
+            "node-name": "NODE_NAME"
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+
+=== blockstats with -blockdev ===
+
+Testing: -blockdev driver=null-co,node-name=null
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+
+=== blockstats with -blockdev and -device ===
+
+Testing: -blockdev driver=null-co,node-name=null -device virtio-blk,drive=null,id=virtio0
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+        {
+            "device": "",
+            "stats": {
+                "flush_total_time_ns": 0,
+                "wr_highest_offset": 0,
+                "wr_total_time_ns": 0,
+                "failed_wr_operations": 0,
+                "failed_rd_operations": 0,
+                "wr_merged": 0,
+                "wr_bytes": 0,
+                "timed_stats": [
+                ],
+                "failed_flush_operations": 0,
+                "account_invalid": false,
+                "rd_total_time_ns": 0,
+                "flush_operations": 0,
+                "wr_operations": 0,
+                "rd_merged": 0,
+                "rd_bytes": 0,
+                "invalid_flush_operations": 0,
+                "account_failed": false,
+                "rd_operations": 0,
+                "invalid_wr_operations": 0,
+                "invalid_rd_operations": 0
+            },
+            "node-name": "null",
+            "qdev": "/machine/peripheral/virtio0/virtio-backend"
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 68f6625..b973dc8 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -224,3 +224,4 @@
 223 rw auto quick
 225 rw auto quick
 226 auto quick
+227 auto quick