Merge tag 'for-upstream' of git://repo.or.cz/qemu/kevin into staging

Block layer patches

- Fix missing block_acct_setup() with -blockdev
- Keep auto_backing_file post-migration
- file-posix: Fixed O_DIRECT memory alignment
- ide: Fix state after EXECUTE DEVICE DIAGNOSTIC and implement
  INITIALIZE DEVICE PARAMETERS
- qemu-img: Wean documentation and help output off '?' for help
- qcow2: fix memory leak and compiler warning
- Code cleanups

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# gpg: Signature made Fri 30 Sep 2022 12:50:54 EDT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* tag 'for-upstream' of git://repo.or.cz/qemu/kevin:
  hw/ide/core.c: Implement ATA INITIALIZE_DEVICE_PARAMETERS command
  tests/qtest/ide-test: Verify that DIAGNOSTIC clears DEV to zero
  hw/ide/core: Clear LBA and drive bits for EXECUTE DEVICE DIAGNOSTIC
  tests/qtest/ide-test.c: Create disk image for use as a secondary
  piix_ide_reset: Use pci_set_* functions instead of direct access
  block: use the request length for iov alignment
  block: move bdrv_qiov_is_aligned to file-posix
  iotests/backing-file-invalidation: Add new test
  block/qed: Keep auto_backing_file if possible
  block/qcow2: Keep auto_backing_file if possible
  gluster: stop using .bdrv_needs_filename
  block: make serializing requests functions 'void'
  block: use bdrv_is_sg() helper instead of raw bs->sg reading
  block: add missed block_acct_setup with new block device init procedure
  block: pass OnOffAuto instead of bool to block_acct_setup()
  qemu-img: Wean documentation and help output off '?' for help
  block/qcow2-bitmap: Add missing cast to silent GCC error
  qcow2: fix memory leak in qcow2_read_extensions

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

5 files changed, 290 insertions, 19 deletions

diff --git a/tests/qemu-iotests/172.out b/tests/qemu-iotests/172.out
index 9479b92..07eebf3 100644
--- a/tests/qemu-iotests/172.out
+++ b/tests/qemu-iotests/172.out
@@ -28,6 +28,8 @@ Testing:
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
 
 
@@ -55,6 +57,8 @@ Testing: -fda TEST_DIR/t.qcow2
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -92,6 +96,8 @@ Testing: -fdb TEST_DIR/t.qcow2
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -104,6 +110,8 @@ Testing: -fdb TEST_DIR/t.qcow2
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
 floppy1 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -145,6 +153,8 @@ Testing: -fda TEST_DIR/t.qcow2 -fdb TEST_DIR/t.qcow2.2
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -157,6 +167,8 @@ Testing: -fda TEST_DIR/t.qcow2 -fdb TEST_DIR/t.qcow2.2
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -199,6 +211,8 @@ Testing: -fdb
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -211,6 +225,8 @@ Testing: -fdb
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
 
 
@@ -238,6 +254,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -275,6 +293,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2,index=1
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -287,6 +307,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2,index=1
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
 floppy1 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -328,6 +350,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=floppy,file=TEST_DIR/t
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -340,6 +364,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=floppy,file=TEST_DIR/t
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -385,6 +411,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
@@ -422,6 +450,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,unit=1
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
@@ -459,6 +489,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qco
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -471,6 +503,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qco
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
@@ -522,6 +556,8 @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -534,6 +570,8 @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -576,6 +614,8 @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -588,6 +628,8 @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -630,6 +672,8 @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 1 (0x1)
@@ -642,6 +686,8 @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy1 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -684,6 +730,8 @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 1 (0x1)
@@ -696,6 +744,8 @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy1 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -747,6 +797,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -759,6 +811,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -801,6 +855,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
               dev: floppy, id ""
                 unit = 0 (0x0)
@@ -813,6 +869,8 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 floppy0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/unattached/device[N]
@@ -861,6 +919,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -global floppy.drive=none0 -device
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
@@ -928,6 +988,8 @@ Testing: -device floppy
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
 
 Testing: -device floppy,drive-type=120
@@ -952,6 +1014,8 @@ Testing: -device floppy,drive-type=120
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "120"
 
 Testing: -device floppy,drive-type=144
@@ -976,6 +1040,8 @@ Testing: -device floppy,drive-type=144
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 
 Testing: -device floppy,drive-type=288
@@ -1000,6 +1066,8 @@ Testing: -device floppy,drive-type=288
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
 
 
@@ -1027,6 +1095,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,drive-t
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "120"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
@@ -1064,6 +1134,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,drive-t
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "288"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
@@ -1104,6 +1176,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,logical
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
@@ -1141,6 +1215,8 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,physica
                 discard_granularity = 4294967295 (4 GiB)
                 write-cache = "auto"
                 share-rw = false
+                account-invalid = "auto"
+                account-failed = "auto"
                 drive-type = "144"
 none0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
     Attached to:      /machine/peripheral-anon/device[N]
diff --git a/tests/qemu-iotests/227.out b/tests/qemu-iotests/227.out
index 9c09ee3..378c1b8 100644
--- a/tests/qemu-iotests/227.out
+++ b/tests/qemu-iotests/227.out
@@ -188,7 +188,7 @@ Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device virtio-b
                 ],
                 "failed_unmap_operations": 0,
                 "failed_flush_operations": 0,
-                "account_invalid": false,
+                "account_invalid": true,
                 "rd_total_time_ns": 0,
                 "invalid_unmap_operations": 0,
                 "flush_operations": 0,
@@ -198,7 +198,7 @@ Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device virtio-b
                 "rd_bytes": 0,
                 "unmap_total_time_ns": 0,
                 "invalid_flush_operations": 0,
-                "account_failed": false,
+                "account_failed": true,
                 "rd_operations": 0,
                 "invalid_wr_operations": 0,
                 "invalid_rd_operations": 0
diff --git a/tests/qemu-iotests/tests/backing-file-invalidation b/tests/qemu-iotests/tests/backing-file-invalidation
new file mode 100755
index 0000000..4eccc80
--- /dev/null
+++ b/tests/qemu-iotests/tests/backing-file-invalidation
@@ -0,0 +1,152 @@
+#!/usr/bin/env python3
+# group: rw migration
+#
+# Migrate a VM with a BDS with backing nodes, which runs
+# bdrv_invalidate_cache(), which for qcow2 and qed triggers reading the
+# backing file string from the image header.  Check whether this
+# interferes with bdrv_backing_overridden().
+#
+# Copyright (C) 2022 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/>.
+#
+
+import json
+import os
+from typing import Optional
+
+import iotests
+from iotests import qemu_img_create, qemu_img_info
+
+
+image_size = 1 * 1024 * 1024
+imgs = [os.path.join(iotests.test_dir, f'{i}.img') for i in range(0, 4)]
+
+mig_sock = os.path.join(iotests.sock_dir, 'mig.sock')
+
+
+class TestPostMigrateFilename(iotests.QMPTestCase):
+    vm_s: Optional[iotests.VM] = None
+    vm_d: Optional[iotests.VM] = None
+
+    def setUp(self) -> None:
+        # Create backing chain of three images, where the backing file strings
+        # are json:{} filenames
+        qemu_img_create('-f', iotests.imgfmt, imgs[0], str(image_size))
+        for i in range(1, 3):
+            backing = {
+                'driver': iotests.imgfmt,
+                'file': {
+                    'driver': 'file',
+                    'filename': imgs[i - 1]
+                }
+            }
+            qemu_img_create('-f', iotests.imgfmt, '-F', iotests.imgfmt,
+                            '-b', 'json:' + json.dumps(backing),
+                            imgs[i], str(image_size))
+
+    def tearDown(self) -> None:
+        if self.vm_s is not None:
+            self.vm_s.shutdown()
+        if self.vm_d is not None:
+            self.vm_d.shutdown()
+
+        for img in imgs:
+            try:
+                os.remove(img)
+            except OSError:
+                pass
+        try:
+            os.remove(mig_sock)
+        except OSError:
+            pass
+
+    def test_migration(self) -> None:
+        """
+        Migrate a VM with the backing chain created in setUp() attached.  At
+        the end of the migration process, the destination will run
+        bdrv_invalidate_cache(), which for some image formats (qcow2 and qed)
+        means the backing file string is re-read from the image header.  If
+        this overwrites bs->auto_backing_file, doing so may cause
+        bdrv_backing_overridden() to become true: The image header reports a
+        json:{} filename, but when opening it, bdrv_refresh_filename() will
+        simplify it to a plain simple filename; and when bs->auto_backing_file
+        and bs->backing->bs->filename differ, bdrv_backing_overridden() becomes
+        true.
+        If bdrv_backing_overridden() is true, the BDS will be forced to get a
+        json:{} filename, which in general is not the end of the world, but not
+        great.  Check whether that happens, i.e. whether migration changes the
+        node's filename.
+        """
+
+        blockdev = {
+            'node-name': 'node0',
+            'driver': iotests.imgfmt,
+            'file': {
+                'driver': 'file',
+                'filename': imgs[2]
+            }
+        }
+
+        self.vm_s = iotests.VM(path_suffix='a') \
+                           .add_blockdev(json.dumps(blockdev))
+        self.vm_d = iotests.VM(path_suffix='b') \
+                           .add_blockdev(json.dumps(blockdev)) \
+                           .add_incoming(f'unix:{mig_sock}')
+
+        assert self.vm_s is not None
+        assert self.vm_d is not None
+
+        self.vm_s.launch()
+        self.vm_d.launch()
+
+        pre_mig_filename = self.vm_s.node_info('node0')['file']
+
+        self.vm_s.qmp('migrate', uri=f'unix:{mig_sock}')
+
+        # Wait for migration to be done
+        self.vm_s.event_wait('STOP')
+        self.vm_d.event_wait('RESUME')
+
+        post_mig_filename = self.vm_d.node_info('node0')['file']
+
+        # Verify that the filename hasn't changed from before the migration
+        self.assertEqual(pre_mig_filename, post_mig_filename)
+
+        self.vm_s.shutdown()
+        self.vm_s = None
+
+        # For good measure, try creating an overlay and check its backing
+        # chain below.  This is how the issue was originally found.
+        result = self.vm_d.qmp('blockdev-snapshot-sync',
+                               format=iotests.imgfmt,
+                               snapshot_file=imgs[3],
+                               node_name='node0',
+                               snapshot_node_name='node0-overlay')
+        self.assert_qmp(result, 'return', {})
+
+        self.vm_d.shutdown()
+        self.vm_d = None
+
+        # Check the newly created overlay's backing chain
+        chain = qemu_img_info('--backing-chain', imgs[3])
+        for index, image in enumerate(chain):
+            self.assertEqual(image['filename'], imgs[3 - index])
+
+
+if __name__ == '__main__':
+    # These are the image formats that run their open() function from their
+    # .bdrv_co_invaliate_cache() implementations, so test them
+    iotests.main(supported_fmts=['qcow2', 'qed'],
+                 supported_protocols=['file'])
diff --git a/tests/qemu-iotests/tests/backing-file-invalidation.out b/tests/qemu-iotests/tests/backing-file-invalidation.out
new file mode 100644
index 0000000..ae1213e
--- /dev/null
+++ b/tests/qemu-iotests/tests/backing-file-invalidation.out
@@ -0,0 +1,5 @@
+.
+----------------------------------------------------------------------
+Ran 1 tests
+
+OK
diff --git a/tests/qtest/ide-test.c b/tests/qtest/ide-test.c
index 4ea89c2..dbe1563 100644
--- a/tests/qtest/ide-test.c
+++ b/tests/qtest/ide-test.c
@@ -90,6 +90,7 @@ enum {
 
 enum {
     CMD_DSM         = 0x06,
+    CMD_DIAGNOSE    = 0x90,
     CMD_READ_DMA    = 0xc8,
     CMD_WRITE_DMA   = 0xca,
     CMD_FLUSH_CACHE = 0xe7,
@@ -121,7 +122,7 @@ enum {
 static QPCIBus *pcibus = NULL;
 static QGuestAllocator guest_malloc;
 
-static char *tmp_path;
+static char *tmp_path[2];
 static char *debug_path;
 
 static QTestState *ide_test_start(const char *cmdline_fmt, ...)
@@ -310,7 +311,7 @@ static QTestState *test_bmdma_setup(void)
     qts = ide_test_start(
         "-drive file=%s,if=ide,cache=writeback,format=raw "
         "-global ide-hd.serial=%s -global ide-hd.ver=%s",
-        tmp_path, "testdisk", "version");
+        tmp_path[0], "testdisk", "version");
     qtest_irq_intercept_in(qts, "ioapic");
 
     return qts;
@@ -574,7 +575,7 @@ static void test_identify(void)
     qts = ide_test_start(
         "-drive file=%s,if=ide,cache=writeback,format=raw "
         "-global ide-hd.serial=%s -global ide-hd.ver=%s",
-        tmp_path, "testdisk", "version");
+        tmp_path[0], "testdisk", "version");
 
     dev = get_pci_device(qts, &bmdma_bar, &ide_bar);
 
@@ -614,6 +615,36 @@ static void test_identify(void)
     free_pci_device(dev);
 }
 
+static void test_diagnostic(void)
+{
+    QTestState *qts;
+    QPCIDevice *dev;
+    QPCIBar bmdma_bar, ide_bar;
+    uint8_t data;
+
+    qts = ide_test_start(
+        "-blockdev driver=file,node-name=hda,filename=%s "
+        "-blockdev driver=file,node-name=hdb,filename=%s "
+        "-device ide-hd,drive=hda,bus=ide.0,unit=0 "
+        "-device ide-hd,drive=hdb,bus=ide.0,unit=1 ",
+        tmp_path[0], tmp_path[1]);
+
+    dev = get_pci_device(qts, &bmdma_bar, &ide_bar);
+
+    /* DIAGNOSE command on device 1 */
+    qpci_io_writeb(dev, ide_bar, reg_device, DEV);
+    data = qpci_io_readb(dev, ide_bar, reg_device);
+    g_assert_cmphex(data & DEV, ==, DEV);
+    qpci_io_writeb(dev, ide_bar, reg_command, CMD_DIAGNOSE);
+
+    /* Verify that DEVICE is now 0 */
+    data = qpci_io_readb(dev, ide_bar, reg_device);
+    g_assert_cmphex(data & DEV, ==, 0);
+
+    ide_test_quit(qts);
+    free_pci_device(dev);
+}
+
 /*
  * Write sector 1 with random data to make IDE storage dirty
  * Needed for flush tests so that flushes actually go though the block layer
@@ -662,7 +693,7 @@ static void test_flush(void)
 
     qts = ide_test_start(
         "-drive file=blkdebug::%s,if=ide,cache=writeback,format=raw",
-        tmp_path);
+        tmp_path[0]);
 
     dev = get_pci_device(qts, &bmdma_bar, &ide_bar);
 
@@ -713,7 +744,7 @@ static void test_pci_retry_flush(void)
     qts = ide_test_start(
         "-drive file=blkdebug:%s:%s,if=ide,cache=writeback,format=raw,"
         "rerror=stop,werror=stop",
-        debug_path, tmp_path);
+        debug_path, tmp_path[0]);
 
     dev = get_pci_device(qts, &bmdma_bar, &ide_bar);
 
@@ -892,14 +923,14 @@ static void cdrom_pio_impl(int nblocks)
 
     /* Prepopulate the CDROM with an interesting pattern */
     generate_pattern(pattern, patt_len, ATAPI_BLOCK_SIZE);
-    fh = fopen(tmp_path, "wb+");
+    fh = fopen(tmp_path[0], "wb+");
     ret = fwrite(pattern, ATAPI_BLOCK_SIZE, patt_blocks, fh);
     g_assert_cmpint(ret, ==, patt_blocks);
     fclose(fh);
 
     qts = ide_test_start(
             "-drive if=none,file=%s,media=cdrom,format=raw,id=sr0,index=0 "
-            "-device ide-cd,drive=sr0,bus=ide.0", tmp_path);
+            "-device ide-cd,drive=sr0,bus=ide.0", tmp_path[0]);
     dev = get_pci_device(qts, &bmdma_bar, &ide_bar);
     qtest_irq_intercept_in(qts, "ioapic");
 
@@ -985,7 +1016,7 @@ static void test_cdrom_dma(void)
 
     qts = ide_test_start(
             "-drive if=none,file=%s,media=cdrom,format=raw,id=sr0,index=0 "
-            "-device ide-cd,drive=sr0,bus=ide.0", tmp_path);
+            "-device ide-cd,drive=sr0,bus=ide.0", tmp_path[0]);
     qtest_irq_intercept_in(qts, "ioapic");
 
     guest_buf = guest_alloc(&guest_malloc, len);
@@ -993,7 +1024,7 @@ static void test_cdrom_dma(void)
     prdt[0].size = cpu_to_le32(len | PRDT_EOT);
 
     generate_pattern(pattern, ATAPI_BLOCK_SIZE * 16, ATAPI_BLOCK_SIZE);
-    fh = fopen(tmp_path, "wb+");
+    fh = fopen(tmp_path[0], "wb+");
     ret = fwrite(pattern, ATAPI_BLOCK_SIZE, 16, fh);
     g_assert_cmpint(ret, ==, 16);
     fclose(fh);
@@ -1012,6 +1043,7 @@ static void test_cdrom_dma(void)
 int main(int argc, char **argv)
 {
     const char *base;
+    int i;
     int fd;
     int ret;
 
@@ -1035,18 +1067,22 @@ int main(int argc, char **argv)
     close(fd);
 
     /* Create a temporary raw image */
-    tmp_path = g_strdup_printf("%s/qtest.XXXXXX", base);
-    fd = g_mkstemp(tmp_path);
-    g_assert(fd >= 0);
-    ret = ftruncate(fd, TEST_IMAGE_SIZE);
-    g_assert(ret == 0);
-    close(fd);
+    for (i = 0; i < 2; ++i) {
+        tmp_path[i] = g_strdup_printf("%s/qtest.XXXXXX", base);
+        fd = g_mkstemp(tmp_path[i]);
+        g_assert(fd >= 0);
+        ret = ftruncate(fd, TEST_IMAGE_SIZE);
+        g_assert(ret == 0);
+        close(fd);
+    }
 
     /* Run the tests */
     g_test_init(&argc, &argv, NULL);
 
     qtest_add_func("/ide/identify", test_identify);
 
+    qtest_add_func("/ide/diagnostic", test_diagnostic);
+
     qtest_add_func("/ide/bmdma/simple_rw", test_bmdma_simple_rw);
     qtest_add_func("/ide/bmdma/trim", test_bmdma_trim);
     qtest_add_func("/ide/bmdma/various_prdts", test_bmdma_various_prdts);
@@ -1064,8 +1100,10 @@ int main(int argc, char **argv)
     ret = g_test_run();
 
     /* Cleanup */
-    unlink(tmp_path);
-    g_free(tmp_path);
+    for (i = 0; i < 2; ++i) {
+        unlink(tmp_path[i]);
+        g_free(tmp_path[i]);
+    }
     unlink(debug_path);
     g_free(debug_path);