bd57f8f7f8
Rewrite bdrv_check_perm(), bdrv_abort_perm_update() and bdrv_set_perm()
to update nodes in topological sort order instead of simple DFS. With
topologically sorted nodes, we update a node only when all its parents
already updated. With DFS it's not so.
Consider the following example:
A -+
| |
| v
| B
| |
v |
C<-+
A is parent for B and C, B is parent for C.
Obviously, to update permissions, we should go in order A B C, so, when
we update C, all parent permissions already updated. But with current
approach (simple recursion) we can update in sequence A C B C (C is
updated twice). On first update of C, we consider old B permissions, so
doing wrong thing. If it succeed, all is OK, on second C update we will
finish with correct graph. But if the wrong thing failed, we break the
whole process for no reason (it's possible that updated B permission
will be less strict, but we will never check it).
Also new approach gives a way to simultaneously and correctly update
several nodes, we just need to run bdrv_topological_dfs() several times
to add all nodes and their subtrees into one topologically sorted list
(next patch will update bdrv_replace_node() in this manner).
Test test_parallel_perm_update() is now passing, so move it out of
debugging "if".
We also need to support ignore_children in
bdrv_parent_perms_conflict()
For test 283 order of conflicting parents check is changed.
Note also that in bdrv_check_perm() we don't check for parents conflict
at root bs, as we may be in the middle of permission update in
bdrv_reopen_multiple(). bdrv_reopen_multiple() will be updated soon.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-14-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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| .. | ||
| check-block-qdict.c | ||
| check-qdict.c | ||
| check-qjson.c | ||
| check-qlist.c | ||
| check-qlit.c | ||
| check-qnull.c | ||
| check-qnum.c | ||
| check-qobject.c | ||
| check-qom-interface.c | ||
| check-qom-proplist.c | ||
| check-qstring.c | ||
| crypto-tls-psk-helpers.c | ||
| crypto-tls-psk-helpers.h | ||
| crypto-tls-x509-helpers.c | ||
| crypto-tls-x509-helpers.h | ||
| io-channel-helpers.c | ||
| io-channel-helpers.h | ||
| iothread.c | ||
| iothread.h | ||
| meson.build | ||
| pkix_asn1_tab.c | ||
| ptimer-test-stubs.c | ||
| ptimer-test.c | ||
| ptimer-test.h | ||
| rcutorture.c | ||
| socket-helpers.c | ||
| socket-helpers.h | ||
| test-aio-multithread.c | ||
| test-aio.c | ||
| test-authz-list.c | ||
| test-authz-listfile.c | ||
| test-authz-pam.c | ||
| test-authz-simple.c | ||
| test-base64.c | ||
| test-bdrv-drain.c | ||
| test-bdrv-graph-mod.c | ||
| test-bitcnt.c | ||
| test-bitmap.c | ||
| test-bitops.c | ||
| test-block-backend.c | ||
| test-block-iothread.c | ||
| test-blockjob-txn.c | ||
| test-blockjob.c | ||
| test-bufferiszero.c | ||
| test-char.c | ||
| test-clone-visitor.c | ||
| test-coroutine.c | ||
| test-crypto-afsplit.c | ||
| test-crypto-block.c | ||
| test-crypto-cipher.c | ||
| test-crypto-hash.c | ||
| test-crypto-hmac.c | ||
| test-crypto-ivgen.c | ||
| test-crypto-pbkdf.c | ||
| test-crypto-secret.c | ||
| test-crypto-tlscredsx509.c | ||
| test-crypto-tlssession.c | ||
| test-crypto-xts.c | ||
| test-cutils.c | ||
| test-fdmon-epoll.c | ||
| test-hbitmap.c | ||
| test-image-locking.c | ||
| test-int128.c | ||
| test-io-channel-buffer.c | ||
| test-io-channel-command.c | ||
| test-io-channel-file.c | ||
| test-io-channel-socket.c | ||
| test-io-channel-tls.c | ||
| test-io-task.c | ||
| test-iov.c | ||
| test-keyval.c | ||
| test-logging.c | ||
| test-mul64.c | ||
| test-opts-visitor.c | ||
| test-qapi-util.c | ||
| test-qdev-global-props.c | ||
| test-qdist.c | ||
| test-qemu-opts.c | ||
| test-qga.c | ||
| test-qgraph.c | ||
| test-qht.c | ||
| test-qmp-cmds.c | ||
| test-qmp-event.c | ||
| test-qobject-input-visitor.c | ||
| test-qobject-output-visitor.c | ||
| test-rcu-list.c | ||
| test-rcu-simpleq.c | ||
| test-rcu-slist.c | ||
| test-rcu-tailq.c | ||
| test-replication.c | ||
| test-shift128.c | ||
| test-string-input-visitor.c | ||
| test-string-output-visitor.c | ||
| test-thread-pool.c | ||
| test-throttle.c | ||
| test-timed-average.c | ||
| test-util-filemonitor.c | ||
| test-util-sockets.c | ||
| test-uuid.c | ||
| test-visitor-serialization.c | ||
| test-vmstate.c | ||
| test-write-threshold.c | ||
| test-x86-cpuid.c | ||
| test-xbzrle.c | ||
| test-yank.c | ||