* [Qemu-devel] [PATCH 1/2] block: Drain source node in bdrv_replace_node()
2019-05-21 19:16 [Qemu-devel] [PATCH 0/2] commit: Fix crash on job start with active I/O Kevin Wolf
@ 2019-05-21 19:16 ` Kevin Wolf
2019-05-22 11:28 ` Max Reitz
2019-05-21 19:16 ` [Qemu-devel] [PATCH 2/2] iotests: Test commit job start with concurrent I/O Kevin Wolf
1 sibling, 1 reply; 5+ messages in thread
From: Kevin Wolf @ 2019-05-21 19:16 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, qemu-devel, mreitz
Instead of just asserting that no requests are in flight in
bdrv_replace_node(), which is a requirement that most callers ignore, we
can just drain the source node right there. This fixes at least starting
a commit job while I/O is active on the backing chain, but probably
other callers, too.
Having requests in flight on the target node isn't a problem because the
target just gets new parents, but the call path of running requests
isn't modified. So we can just drop this assertion without a replacement.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1711643
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/block.c b/block.c
index cb11537029..75f370dbba 100644
--- a/block.c
+++ b/block.c
@@ -4021,13 +4021,13 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
uint64_t perm = 0, shared = BLK_PERM_ALL;
int ret;
- assert(!atomic_read(&from->in_flight));
- assert(!atomic_read(&to->in_flight));
-
/* Make sure that @from doesn't go away until we have successfully attached
* all of its parents to @to. */
bdrv_ref(from);
+ assert(qemu_get_current_aio_context() == qemu_get_aio_context());
+ bdrv_drained_begin(from);
+
/* Put all parents into @list and calculate their cumulative permissions */
QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
assert(c->bs == from);
@@ -4068,6 +4068,7 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
out:
g_slist_free(list);
+ bdrv_drained_end(from);
bdrv_unref(from);
}
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [Qemu-devel] [PATCH 2/2] iotests: Test commit job start with concurrent I/O
2019-05-21 19:16 [Qemu-devel] [PATCH 0/2] commit: Fix crash on job start with active I/O Kevin Wolf
2019-05-21 19:16 ` [Qemu-devel] [PATCH 1/2] block: Drain source node in bdrv_replace_node() Kevin Wolf
@ 2019-05-21 19:16 ` Kevin Wolf
2019-05-22 11:48 ` Max Reitz
1 sibling, 1 reply; 5+ messages in thread
From: Kevin Wolf @ 2019-05-21 19:16 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, qemu-devel, mreitz
This tests that concurrent requests are correctly drained before making
graph modifications instead of running into assertions in
bdrv_replace_node().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
tests/qemu-iotests/255 | 83 +++++++++++++++++++++++++++++++++++
tests/qemu-iotests/255.out | 16 +++++++
tests/qemu-iotests/group | 1 +
tests/qemu-iotests/iotests.py | 10 ++++-
4 files changed, 109 insertions(+), 1 deletion(-)
create mode 100755 tests/qemu-iotests/255
create mode 100644 tests/qemu-iotests/255.out
diff --git a/tests/qemu-iotests/255 b/tests/qemu-iotests/255
new file mode 100755
index 0000000000..c0bb37a9b0
--- /dev/null
+++ b/tests/qemu-iotests/255
@@ -0,0 +1,83 @@
+#!/usr/bin/env python
+#
+# Test commit job graph modifications while requests are active
+#
+# Copyright (C) 2019 Red Hat, Inc.
+#
+# Creator/Owner: Kevin Wolf <kwolf@redhat.com>
+#
+# 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 iotests
+from iotests import imgfmt
+
+iotests.verify_image_format(supported_fmts=['qcow2'])
+
+def blockdev_create(vm, options):
+ result = vm.qmp_log('blockdev-create',
+ filters=[iotests.filter_qmp_testfiles],
+ job_id='job0', options=options)
+
+ if 'return' in result:
+ assert result['return'] == {}
+ vm.run_job('job0')
+ iotests.log("")
+
+with iotests.FilePath('t.qcow2') as disk_path, \
+ iotests.FilePath('t.qcow2.mid') as mid_path, \
+ iotests.FilePath('t.qcow2.base') as base_path, \
+ iotests.VM() as vm:
+
+ iotests.log("=== Create backing chain and start VM ===")
+ iotests.log("")
+
+ size = 128 * 1024 * 1024
+ size_str = str(size)
+
+ iotests.create_image(base_path, size)
+ iotests.qemu_img_log('create', '-f', iotests.imgfmt, mid_path, size_str)
+ iotests.qemu_img_log('create', '-f', iotests.imgfmt, disk_path, size_str)
+
+ # Create a backing chain like this:
+ # base <- [throttled: bps-read=4096] <- mid <- overlay
+
+ vm.add_object('throttle-group,x-bps-read=4096,id=throttle0')
+ vm.add_blockdev('file,filename=%s,node-name=base' % (base_path))
+ vm.add_blockdev('throttle,throttle-group=throttle0,file=base,node-name=throttled')
+ vm.add_blockdev('file,filename=%s,node-name=mid-file' % (mid_path))
+ vm.add_blockdev('qcow2,file=mid-file,node-name=mid,backing=throttled')
+ vm.add_drive_raw('if=none,id=overlay,driver=qcow2,file=%s,backing=mid' % (disk_path))
+
+ vm.launch()
+
+ iotests.log("=== Start background read requests ===")
+ iotests.log("")
+
+ def start_requests():
+ vm.hmp_qemu_io('overlay', 'aio_read 0 4k')
+ vm.hmp_qemu_io('overlay', 'aio_read 0 4k')
+
+ start_requests()
+
+ iotests.log("=== Run a commit job ===")
+ iotests.log("")
+
+ result = vm.qmp_log('block-commit', job_id='job0', auto_finalize=False,
+ device='overlay', top_node='mid')
+
+ vm.run_job('job0', auto_finalize=False, pre_finalize=start_requests,
+ auto_dismiss=True)
+
+ vm.shutdown()
diff --git a/tests/qemu-iotests/255.out b/tests/qemu-iotests/255.out
new file mode 100644
index 0000000000..9a2d7cbb77
--- /dev/null
+++ b/tests/qemu-iotests/255.out
@@ -0,0 +1,16 @@
+=== Create backing chain and start VM ===
+
+Formatting 'TEST_DIR/PID-t.qcow2.mid', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+
+Formatting 'TEST_DIR/PID-t.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+
+=== Start background read requests ===
+
+=== Run a commit job ===
+
+{"execute": "block-commit", "arguments": {"auto-finalize": false, "device": "overlay", "job-id": "job0", "top-node": "mid"}}
+{"return": {}}
+{"execute": "job-finalize", "arguments": {"id": "job0"}}
+{"return": {}}
+{"data": {"id": "job0", "type": "commit"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"device": "job0", "len": 134217728, "offset": 134217728, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 52b7c16e15..2758f48143 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -251,3 +251,4 @@
249 rw auto quick
252 rw auto backing quick
253 rw auto quick
+255 rw auto quick
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 7bde380d96..6bcddd8870 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -126,6 +126,11 @@ def qemu_img_pipe(*args):
sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
return subp.communicate()[0]
+def qemu_img_log(*args):
+ result = qemu_img_pipe(*args)
+ log(result, filters=[filter_testfiles])
+ return result
+
def img_info_log(filename, filter_path=None, imgopts=False, extra_args=[]):
args = [ 'info' ]
if imgopts:
@@ -533,7 +538,8 @@ class VM(qtest.QEMUQtestMachine):
return result
# Returns None on success, and an error string on failure
- def run_job(self, job, auto_finalize=True, auto_dismiss=False):
+ def run_job(self, job, auto_finalize=True, auto_dismiss=False,
+ pre_finalize=None):
error = None
while True:
for ev in self.get_qmp_events_filtered(wait=True):
@@ -546,6 +552,8 @@ class VM(qtest.QEMUQtestMachine):
error = j['error']
log('Job failed: %s' % (j['error']))
elif status == 'pending' and not auto_finalize:
+ if pre_finalize:
+ pre_finalize()
self.qmp_log('job-finalize', id=job)
elif status == 'concluded' and not auto_dismiss:
self.qmp_log('job-dismiss', id=job)
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread