block: Fix crash on migration with explicit child nodes
v2 cover block: Fix crash on migration with explicit child nodes
v2:
- Cover children that were created after their parents [Max]
Kevin Wolf (2):
block: Don't inactivate children before parents
iotests: Test migration with -blockdev
block.c | 32 ++++++++++- tests/qemu-iotests/234 | 115 +++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/234.out | 27 +++++++++ tests/qemu-iotests/group | 1 + 4 files changed, 174 insertions(+), 1 deletion(-) create mode 100755 tests/qemu-iotests/234 create mode 100644 tests/qemu-iotests/234.out
Signature · 1 line
2.19.1
PATCH v2 1/2 block: Don't inactivate children before parents
bdrv_child_cb_inactivate() asserts that parents are already inactive when children get inactivated. This precondition is necessary because parents could still issue requests in their inactivation code.
When block nodes are created individually with -blockdev, all of them are monitor owned and will be returned by bdrv_next() in an undefined order (in practice, in the order of their creation, which is usually children before parents), which obviously fails the assertion:
qemu: block.c:899: bdrv_child_cb_inactivate: Assertion `bs->open_flags & BDRV_O_INACTIVE' failed.
This patch fixes the ordering by skipping nodes with still active parents in bdrv_inactivate_recurse() because we know that they will be covered by recursion when the last active parent becomes inactive.
Signed-off-by Kevin Wolf <[email protected]>
--- block.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-)
block.c +31 -1
@@ -4612,6 +4612,22 @@ void bdrv_invalidate_cache_all(Error **errp) } } +static bool bdrv_has_bds_parent (BlockDriverState *bs,bool only_active) +{ +BdrvChild *parent; + + QLIST_FOREACH(parent, &bs->parents, next_parent) { +if (parent->role->parent_is_bds) { +BlockDriverState *parent_bs = parent->opaque; +if (!only_active || !(parent_bs->open_flags &BDRV_O_INACTIVE )) { +return true; + } + } + } + +return false; +} +static int bdrv_inactivate_recurse (BlockDriverState *bs,bool setting_flag) {
@@ -4622,6 +4638,14 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs,return -ENOMEDIUM ; } +/* Make sure that we don't inactivate a child before its parent. +* It will be covered by recursion from the yet active parent. */ +if (bdrv_has_bds_parent (bs, true)) { +return 0 ; + } + +assert (!(bs->open_flags &BDRV_O_INACTIVE )); +if (!setting_flag && bs->drv->bdrv_inactivate) { ret = bs->drv->bdrv_inactivate (bs);if (ret <0 ) {
@@ -4629,7 +4653,7 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs, } } -if (setting_flag && !(bs->open_flags &BDRV_O_INACTIVE )) { +if (setting_flag) {uint64_t perm, shared_perm; QLIST_FOREACH(parent, &bs->parents, next_parent) {
@@ -4682,6 +4706,12 @@ int bdrv_inactivate_all(void)* is allowed. */ for (pass =0 ; pass <2 ; pass++) {for (bs =bdrv_first (&it); bs; bs =bdrv_next (&it)) { +/* Nodes with BDS parents are covered by recursion from the last +* parent that gets inactivated. Don't inactivate them a second +* time if that has already happened. */ +if (bdrv_has_bds_parent (bs, false)) { +continue ; + } ret =bdrv_inactivate_recurse (bs, pass);if (ret <0 ) {bdrv_next_cleanup (&it);
Signature · 1 line
2.19.1
Re: [Qemu-devel] [PATCH for-3.1 v2 1/2] block: Don't inactivate children before parents
Quoted 24 lines · Kevin Wolf
bdrv_child_cb_inactivate()asserts that parents are already inactive when children get inactivated. This precondition is necessary because parents could still issue requests in their inactivation code.When block nodes are created individually with -blockdev, all of them are monitor owned and will be returned by
bdrv_next()in an undefined order (in practice, in the order of their creation, which is usually children before parents), which obviously fails the assertion:qemu: block.c:899:
bdrv_child_cb_inactivate: Assertion `bs->open_flags &BDRV_O_INACTIVE' failed.This patch fixes the ordering by skipping nodes with still active parents in
bdrv_inactivate_recurse()because we know that they will be covered by recursion when the last active parent becomes inactive.Signed-off-by Kevin Wolf <[email protected]>--- block.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-)block.c +0
-0
[...]
block.c static int bdrv_inactivate_recurse(BlockDriverState *bs, · line 4643
Quoted 7 lines
block.c +3
-0@@ -4622,6 +4638,14 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs,return -ENOMEDIUM ; } +/* Make sure that we don't inactivate a child before its parent. +* It will be covered by recursion from the yet active parent. */ +if (bdrv_has_bds_parent (bs, true)) {
Overall the patch looks good to me, apart from the fact that I still think this should only be checked if setting_flag is true.
(Because BDRV_O_INACTIVE is only set during the second pass, so this check will lead to the first pass not doing anything (and thus not calling bs->drv->bdrv_inactivate()) on any non-root bs.)
Max
Quoted 8 lines
block.c +5
-0+return 0 ; + } + +assert (!(bs->open_flags &BDRV_O_INACTIVE )); +if (!setting_flag && bs->drv->bdrv_inactivate) { ret = bs->drv->bdrv_inactivate (bs);if (ret <0 ) {
PATCH v2 2/2 iotests: Test migration with -blockdev
In reply to Kevin WolfCheck that block node activation and inactivation works with a block graph that is built with individually created nodes.
Signed-off-by Kevin Wolf <[email protected]>
--- tests/qemu-iotests/234 | 115 +++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/234.out | 27 +++++++++ tests/qemu-iotests/group | 1 + 3 files changed, 143 insertions(+) create mode 100755 tests/qemu-iotests/234 create mode 100644 tests/qemu-iotests/234.out
tests/qemu-iotests/234 new file +115 -0
@@ -0,0 +1,115 @@ +#!/usr/bin/env python +# +# 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: Kevin Wolf <[email protected]> +# +# Check that block node activation and inactivation works with a block graph +# that is built with individually created nodes + +import iotests +import os + +iotests.verify_image_format(supported_fmts=['raw', 'qcow2']) +iotests.verify_platform(['linux']) + +with iotests.FilePath('img') as img_path, \ + iotests.FilePath('backing') as backing_path, \ + iotests.FilePath('mig_fifo_a') as fifo_a, \ + iotests.FilePath('mig_fifo_b') as fifo_b, \ + iotests.VM(path_suffix='a') as vm_a, \ + iotests.VM(path_suffix='b') as vm_b: + + iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, backing_path, '64M') + iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, img_path, '64M') + + os.mkfifo(fifo_a) + os.mkfifo(fifo_b) + + iotests.log('Launching source VM...') + (vm_a.add_blockdev('file,filename=%s,node-name=drive0-file' % (img_path)) + .add_blockdev('%s,file=drive0-file,node-name=drive0' % (iotests.imgfmt)) + .add_blockdev('file,filename=%s,node-name=drive0-backing-file' % (backing_path)) + .add_blockdev('%s,file=drive0-backing-file,node-name=drive0-backing' % (iotests.imgfmt)) + .launch()) + + iotests.log('Launching destination VM...') + (vm_b.add_blockdev('file,filename=%s,node-name=drive0-file' % (img_path)) + .add_blockdev('%s,file=drive0-file,node-name=drive0' % (iotests.imgfmt)) + .add_blockdev('file,filename=%s,node-name=drive0-backing-file' % (backing_path)) + .add_blockdev('%s,file=drive0-backing-file,node-name=drive0-backing' % (iotests.imgfmt)) + .add_incoming("exec: cat '%s'" % (fifo_a)) + .launch()) + + # Add a child node that was created after the parent node. The reverse case + # is covered by the -blockdev options above. + vm_a.qmp('blockdev-snapshot', node='drive0-backing', overlay='drive0') + + iotests.log('Enabling migration QMP events on A...') + iotests.log(vm_a.qmp('migrate-set-capabilities', capabilities=[ + { + 'capability': 'events', + 'state': True + } + ])) + + iotests.log('Starting migration to B...') + iotests.log(vm_a.qmp('migrate', uri='exec:cat >%s' % (fifo_a))) + with iotests.Timeout(3, 'Migration does not complete'): + while True: + event = vm_a.event_wait('MIGRATION') + iotests.log(event, filters=[iotests.filter_qmp_event]) + if event['data']['status'] == 'completed': + break + + iotests.log(vm_a.qmp('query-migrate')['return']['status']) + iotests.log(vm_b.qmp('query-migrate')['return']['status']) + + iotests.log(vm_a.qmp('query-status')) + iotests.log(vm_b.qmp('query-status')) + + iotests.log('Add a second parent to drive0-file...') + iotests.log(vm_b.qmp('blockdev-add', driver='raw', file='drive0-file', + node_name='drive0-raw')) + + iotests.log('Restart A with -incoming and second parent...') + vm_a.shutdown() + (vm_a.add_blockdev('raw,file=drive0-file,node-name=drive0-raw') + .add_incoming("exec: cat '%s'" % (fifo_b)) + .launch()) + + iotests.log('Enabling migration QMP events on B...') + iotests.log(vm_b.qmp('migrate-set-capabilities', capabilities=[ + { + 'capability': 'events', + 'state': True + } + ])) + + iotests.log('Starting migration back to A...') + iotests.log(vm_b.qmp('migrate', uri='exec:cat >%s' % (fifo_b))) + with iotests.Timeout(3, 'Migration does not complete'): + while True: + event = vm_b.event_wait('MIGRATION') + iotests.log(event, filters=[iotests.filter_qmp_event]) + if event['data']['status'] == 'completed': + break + + iotests.log(vm_a.qmp('query-migrate')['return']['status']) + iotests.log(vm_b.qmp('query-migrate')['return']['status']) + + iotests.log(vm_a.qmp('query-status')) + iotests.log(vm_b.qmp('query-status'))
tests/qemu-iotests/234.out new file +27 -0
@@ -0,0 +1,27 @@ +Launching source VM... +Launching destination VM... +Enabling migration QMP events on A... +{"return": {}} +Starting migration to B... +{"return": {}} +{"data": {"status": "setup"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "active"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "completed"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +completed +completed +{"return": {"running": false, "singlestep": false, "status": "postmigrate"}} +{"return": {"running": true, "singlestep": false, "status": "running"}} +Add a second parent to drive0-file... +{"return": {}} +Restart A with -incoming and second parent... +Enabling migration QMP events on B... +{"return": {}} +Starting migration back to A... +{"return": {}} +{"data": {"status": "setup"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "active"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "completed"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +completed +completed +{"return": {"running": true, "singlestep": false, "status": "running"}} +{"return": {"running": false, "singlestep": false, "status": "postmigrate"}}
tests/qemu-iotests/group +1 -0
@@ -231,3 +231,4 @@ 231 auto quick 232 auto quick 233 auto quick +234 auto quick migration
Signature · 1 line
2.19.1
Re: [Qemu-devel] [PATCH for-3.1 v2 2/2] iotests: Test migration with -blockdev
Quoted 67 lines · Kevin Wolf
Check that block node activation and inactivation works with a block graph that is built with individually created nodes.
Signed-off-by Kevin Wolf <[email protected]>--- tests/qemu-iotests/234 | 115 +++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/234.out | 27 +++++++++ tests/qemu-iotests/group | 1 + 3 files changed, 143 insertions(+) create mode 100755 tests/qemu-iotests/234 create mode 100644 tests/qemu-iotests/234.outtests/qemu-iotests/234 new file +49
-0@@ -0,0 +1,115 @@ +#!/usr/bin/env python +# +# 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: Kevin Wolf <[email protected]> +# +# Check that block node activation and inactivation works with a block graph +# that is built with individually created nodes + +import iotests +import os + +iotests.verify_image_format(supported_fmts=['raw', 'qcow2']) +iotests.verify_platform(['linux']) + +with iotests.FilePath('img') as img_path, \ + iotests.FilePath('backing') as backing_path, \ + iotests.FilePath('mig_fifo_a') as fifo_a, \ + iotests.FilePath('mig_fifo_b') as fifo_b, \ + iotests.VM(path_suffix='a') as vm_a, \ + iotests.VM(path_suffix='b') as vm_b: + + iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, backing_path, '64M') + iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, img_path, '64M') + + os.mkfifo(fifo_a) + os.mkfifo(fifo_b) + + iotests.log('Launching source VM...') + (vm_a.add_blockdev('file,filename=%s,node-name=drive0-file' % (img_path)) + .add_blockdev('%s,file=drive0-file,node-name=drive0' % (iotests.imgfmt)) + .add_blockdev('file,filename=%s,node-name=drive0-backing-file' % (backing_path)) + .add_blockdev('%s,file=drive0-backing-file,node-name=drive0-backing' % (iotests.imgfmt)) + .launch()) + + iotests.log('Launching destination VM...')
tests/qemu-iotests/234 line 59
Quoted 10 lines
tests/qemu-iotests/234 new file +10
-0+ (vm_b.add_blockdev('file,filename=%s,node-name=drive0-file' % (img_path)) + .add_blockdev('%s,file=drive0-file,node-name=drive0' % (iotests.imgfmt)) + .add_blockdev('file,filename=%s,node-name=drive0-backing-file' % (backing_path)) + .add_blockdev('%s,file=drive0-backing-file,node-name=drive0-backing' % (iotests.imgfmt)) + .add_incoming("exec: cat '%s'" % (fifo_a)) + .launch()) + + # Add a child node that was created after the parent node. The reverse case + # is covered by the -blockdev options above. + vm_a.qmp('blockdev-snapshot', node='drive0-backing', overlay='drive0')
Sorry if I made it sound like my diff was ready for inclusion as-is. O:-)
I think this should be vm_a.qmp_log() at least (and the reference output needs to be adjusted accordingly).
Also, we probably have to execute the same command on vm_b...
Quoted 22 lines
tests/qemu-iotests/234 new file +22
-0+ iotests.log('Enabling migration QMP events on A...') + iotests.log(vm_a.qmp('migrate-set-capabilities', capabilities=[ + { + 'capability': 'events', + 'state': True + } + ])) + + iotests.log('Starting migration to B...') + iotests.log(vm_a.qmp('migrate', uri='exec:cat >%s' % (fifo_a))) + with iotests.Timeout(3, 'Migration does not complete'): + while True: + event = vm_a.event_wait('MIGRATION') + iotests.log(event, filters=[iotests.filter_qmp_event]) + if event['data']['status'] == 'completed': + break + + iotests.log(vm_a.qmp('query-migrate')['return']['status']) + iotests.log(vm_b.qmp('query-migrate')['return']['status']) + + iotests.log(vm_a.qmp('query-status')) + iotests.log(vm_b.qmp('query-status'))
tests/qemu-iotests/234 line 92
Quoted 10 lines
tests/qemu-iotests/234 new file +10
-0+ + iotests.log('Add a second parent to drive0-file...') + iotests.log(vm_b.qmp('blockdev-add', driver='raw', file='drive0-file', + node_name='drive0-raw')) + + iotests.log('Restart A with -incoming and second parent...') + vm_a.shutdown() + (vm_a.add_blockdev('raw,file=drive0-file,node-name=drive0-raw') + .add_incoming("exec: cat '%s'" % (fifo_b)) + .launch())
...and here on vm_a again?
Max
Quoted 65 lines
tests/qemu-iotests/234 new file +22
-0+ iotests.log('Enabling migration QMP events on B...') + iotests.log(vm_b.qmp('migrate-set-capabilities', capabilities=[ + { + 'capability': 'events', + 'state': True + } + ])) + + iotests.log('Starting migration back to A...') + iotests.log(vm_b.qmp('migrate', uri='exec:cat >%s' % (fifo_b))) + with iotests.Timeout(3, 'Migration does not complete'): + while True: + event = vm_b.event_wait('MIGRATION') + iotests.log(event, filters=[iotests.filter_qmp_event]) + if event['data']['status'] == 'completed': + break + + iotests.log(vm_a.qmp('query-migrate')['return']['status']) + iotests.log(vm_b.qmp('query-migrate')['return']['status']) + + iotests.log(vm_a.qmp('query-status')) + iotests.log(vm_b.qmp('query-status'))tests/qemu-iotests/234.out new file +27
-0@@ -0,0 +1,27 @@ +Launching source VM... +Launching destination VM... +Enabling migration QMP events on A... +{"return": {}} +Starting migration to B... +{"return": {}} +{"data": {"status": "setup"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "active"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "completed"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +completed +completed +{"return": {"running": false, "singlestep": false, "status": "postmigrate"}} +{"return": {"running": true, "singlestep": false, "status": "running"}} +Add a second parent to drive0-file... +{"return": {}} +Restart A with -incoming and second parent... +Enabling migration QMP events on B... +{"return": {}} +Starting migration back to A... +{"return": {}} +{"data": {"status": "setup"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "active"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +{"data": {"status": "completed"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} +completed +completed +{"return": {"running": true, "singlestep": false, "status": "running"}} +{"return": {"running": false, "singlestep": false, "status": "postmigrate"}}tests/qemu-iotests/group +1
-0@@ -231,3 +231,4 @@ 231 auto quick 232 auto quick 233 auto quick +234 auto quick migration