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

Block layer patches

- mirror: Fix active mirror deadlock
- replication: Fix crashes due to operations on wrong BdrvChild
- configure: Add option to use driver whitelist even in tools
- vvfat: Fix crash when opening image read-write
- export: Fix crash in error path with fixed-iothread=false

# gpg: Signature made Tue 20 Jul 2021 16:09:23 BST
# 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

* remotes/kevin/tags/for-upstream:
  iotests/307: Test iothread conflict for exports
  block/export: Conditionally ignore set-context error
  block/vvfat: fix: drop backing
  replication: Remove workaround
  replication: Properly attach children
  replication: Reduce usage of s->hidden_disk and s->secondary_disk
  replication: Remove s->active_disk
  block: Add option to use driver whitelist even in tools
  block/mirror: fix active mirror dead-lock in mirror_wait_on_conflicts
  iotest 151: add test-case that shows active mirror dead-lock
  block/mirror: set .co for active-write MirrorOp objects

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

4 files changed, 77 insertions, 4 deletions

diff --git a/tests/qemu-iotests/151 b/tests/qemu-iotests/151
index 182f6b5321..93d14193d0 100755
--- a/tests/qemu-iotests/151
+++ b/tests/qemu-iotests/151
@@ -38,8 +38,9 @@ class TestActiveMirror(iotests.QMPTestCase):
                       'if': 'none',
                       'node-name': 'source-node',
                       'driver': iotests.imgfmt,
-                      'file': {'driver': 'file',
-                               'filename': source_img}}
+                      'file': {'driver': 'blkdebug',
+                               'image': {'driver': 'file',
+                                         'filename': source_img}}}
 
         blk_target = {'node-name': 'target-node',
                       'driver': iotests.imgfmt,
@@ -141,6 +142,55 @@ class TestActiveMirror(iotests.QMPTestCase):
 
         self.potential_writes_in_flight = False
 
+    def testIntersectingActiveIO(self):
+        # Fill the source image
+        result = self.vm.hmp_qemu_io('source', 'write -P 1 0 2M')
+
+        # Start the block job (very slowly)
+        result = self.vm.qmp('blockdev-mirror',
+                             job_id='mirror',
+                             filter_node_name='mirror-node',
+                             device='source-node',
+                             target='target-node',
+                             sync='full',
+                             copy_mode='write-blocking',
+                             speed=1)
+
+        self.vm.hmp_qemu_io('source', 'break write_aio A')
+        self.vm.hmp_qemu_io('source', 'aio_write 0 1M')  # 1
+        self.vm.hmp_qemu_io('source', 'wait_break A')
+        self.vm.hmp_qemu_io('source', 'aio_write 0 2M')  # 2
+        self.vm.hmp_qemu_io('source', 'aio_write 0 2M')  # 3
+
+        # Now 2 and 3 are in mirror_wait_on_conflicts, waiting for 1
+
+        self.vm.hmp_qemu_io('source', 'break write_aio B')
+        self.vm.hmp_qemu_io('source', 'aio_write 1M 2M')  # 4
+        self.vm.hmp_qemu_io('source', 'wait_break B')
+
+        # 4 doesn't wait for 2 and 3, because they didn't yet set
+        # in_flight_bitmap. So, nothing prevents 4 to go except for our
+        # break-point B.
+
+        self.vm.hmp_qemu_io('source', 'resume A')
+
+        # Now we resumed 1, so 2 and 3 goes to the next iteration of while loop
+        # in mirror_wait_on_conflicts(). They don't exit, as bitmap is dirty
+        # due to request 4.
+        # In the past at that point 2 and 3 would wait for each other producing
+        # a dead-lock. Now this is fixed and they will wait for request 4.
+
+        self.vm.hmp_qemu_io('source', 'resume B')
+
+        # After resuming 4, one of 2 and 3 goes first and set in_flight_bitmap,
+        # so the other will wait for it.
+
+        result = self.vm.qmp('block-job-set-speed', device='mirror', speed=0)
+        self.assert_qmp(result, 'return', {})
+        self.complete_and_wait(drive='mirror')
+
+        self.potential_writes_in_flight = False
+
 
 if __name__ == '__main__':
     iotests.main(supported_fmts=['qcow2', 'raw'],
diff --git a/tests/qemu-iotests/151.out b/tests/qemu-iotests/151.out
index 8d7e996700..89968f35d7 100644
--- a/tests/qemu-iotests/151.out
+++ b/tests/qemu-iotests/151.out
@@ -1,5 +1,5 @@
-...
+....
 ----------------------------------------------------------------------
-Ran 3 tests
+Ran 4 tests
 
 OK
diff --git a/tests/qemu-iotests/307 b/tests/qemu-iotests/307
index c7685347bc..b429b5aa50 100755
--- a/tests/qemu-iotests/307
+++ b/tests/qemu-iotests/307
@@ -41,9 +41,11 @@ with iotests.FilePath('image') as img, \
     iotests.log('=== Launch VM ===')
 
     vm.add_object('iothread,id=iothread0')
+    vm.add_object('iothread,id=iothread1')
     vm.add_blockdev(f'file,filename={img},node-name=file')
     vm.add_blockdev(f'{iotests.imgfmt},file=file,node-name=fmt')
     vm.add_blockdev('raw,file=file,node-name=ro,read-only=on')
+    vm.add_blockdev('null-co,node-name=null')
     vm.add_device(f'id=scsi0,driver=virtio-scsi,iothread=iothread0')
     vm.launch()
 
@@ -74,6 +76,19 @@ with iotests.FilePath('image') as img, \
     vm.qmp_log('query-block-exports')
     iotests.qemu_nbd_list_log('-k', socket)
 
+    iotests.log('\n=== Add export with conflicting iothread ===')
+
+    vm.qmp_log('device_add', id='sdb', driver='scsi-hd', drive='null')
+
+    # Should fail because of fixed-iothread
+    vm.qmp_log('block-export-add', id='export1', type='nbd', node_name='null',
+               iothread='iothread1', fixed_iothread=True, writable=True)
+
+    # Should ignore the iothread conflict, but then fail because of the
+    # permission conflict (and not crash)
+    vm.qmp_log('block-export-add', id='export1', type='nbd', node_name='null',
+               iothread='iothread1', fixed_iothread=False, writable=True)
+
     iotests.log('\n=== Add a writable export ===')
 
     # This fails because share-rw=off
diff --git a/tests/qemu-iotests/307.out b/tests/qemu-iotests/307.out
index 4b0c7e155a..ec8d2be0e0 100644
--- a/tests/qemu-iotests/307.out
+++ b/tests/qemu-iotests/307.out
@@ -51,6 +51,14 @@ exports available: 1
    base:allocation
 
 
+=== Add export with conflicting iothread ===
+{"execute": "device_add", "arguments": {"drive": "null", "driver": "scsi-hd", "id": "sdb"}}
+{"return": {}}
+{"execute": "block-export-add", "arguments": {"fixed-iothread": true, "id": "export1", "iothread": "iothread1", "node-name": "null", "type": "nbd", "writable": true}}
+{"error": {"class": "GenericError", "desc": "Cannot change iothread of active block backend"}}
+{"execute": "block-export-add", "arguments": {"fixed-iothread": false, "id": "export1", "iothread": "iothread1", "node-name": "null", "type": "nbd", "writable": true}}
+{"error": {"class": "GenericError", "desc": "Permission conflict on node 'null': permissions 'write' are both required by an unnamed block device (uses node 'null' as 'root' child) and unshared by block device 'sdb' (uses node 'null' as 'root' child)."}}
+
 === Add a writable export ===
 {"execute": "block-export-add", "arguments": {"description": "This is the writable second export", "id": "export1", "name": "export1", "node-name": "fmt", "type": "nbd", "writable": true, "writethrough": true}}
 {"error": {"class": "GenericError", "desc": "Permission conflict on node 'fmt': permissions 'write' are both required by an unnamed block device (uses node 'fmt' as 'root' child) and unshared by block device 'sda' (uses node 'fmt' as 'root' child)."}}