xemu/tests/qemu-iotests/142.out
Eric Blake b66ff2c298 iotests: Specify explicit backing format where sensible
There are many existing qcow2 images that specify a backing file but
no format.  This has been the source of CVEs in the past, but has
become more prominent of a problem now that libvirt has switched to
-blockdev.  With older -drive, at least the probing was always done by
qemu (so the only risk of a changed format between successive boots of
a guest was if qemu was upgraded and probed differently).  But with
newer -blockdev, libvirt must specify a format; if libvirt guesses raw
where the image was formatted, this results in data corruption visible
to the guest; conversely, if libvirt guesses qcow2 where qemu was
using raw, this can result in potential security holes, so modern
libvirt instead refuses to use images without explicit backing format.

The change in libvirt to reject images without explicit backing format
has pointed out that a number of tools have been far too reliant on
probing in the past.  It's time to set a better example in our own
iotests of properly setting this parameter.

iotest calls to create, rebase, and convert are all impacted to some
degree.  It's a bit annoying that we are inconsistent on command line
- while all of those accept -o backing_file=...,backing_fmt=..., the
shortcuts are different: create and rebase have -b and -F, while
convert has -B but no -F.  (amend has no shortcuts, but the previous
patch just deprecated the use of amend to change backing chains).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-9-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00

751 lines
26 KiB
Plaintext

QA output created by 142
Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=134217728
Formatting 'TEST_DIR/t.IMGFMT.snap', fmt=IMGFMT size=134217728
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.base backing_fmt=IMGFMT
=== Simple test for all cache modes ===
Testing: -drive file=TEST_DIR/t.qcow2,cache=none
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) quit
Testing: -drive file=TEST_DIR/t.qcow2,cache=directsync
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) quit
Testing: -drive file=TEST_DIR/t.qcow2,cache=writeback
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) quit
Testing: -drive file=TEST_DIR/t.qcow2,cache=writethrough
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) quit
Testing: -drive file=TEST_DIR/t.qcow2,cache=unsafe
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) quit
Testing: -drive file=TEST_DIR/t.qcow2,cache=invalid_value
QEMU_PROG: -drive file=TEST_DIR/t.qcow2,cache=invalid_value: invalid cache option
=== Check inheritance of cache modes ===
--- Configure cache modes on the command line ---
cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
cache.direct=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
cache.writeback=off on none0
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.writeback=off on backing
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
cache.writeback=off on backing-file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.no-flush=on on none0
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
cache.no-flush=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
cache.no-flush=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
--- Cache modes after reopen (live snapshot) ---
cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
cache.direct=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
cache.writeback=off on none0
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.writeback=off on backing
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
cache.writeback=off on backing-file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.no-flush=on on none0
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
cache.no-flush=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
cache.no-flush=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
--- Change cache modes with reopen (qemu-io command, flags) ---
cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.writeback=off on backing
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
cache.writeback=off on backing-file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.no-flush=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
--- Change cache modes with reopen (qemu-io command, options) ---
cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on none0
Cache mode: writethrough, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.writeback=off on backing
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
cache.writeback=off on backing-file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.no-flush=on on none0
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
--- Change cache modes after snapshot ---
cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
cache.direct=on on backing
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
cache.writeback=off on none0
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.writeback=off on backing
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
cache.writeback=off on backing-file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.no-flush=on on none0
Cache mode: writeback, direct
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
cache.no-flush=on on file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on backing
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
cache.no-flush=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
--- Change cache mode in parent, child has explicit option in JSON ---
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, ignore flushes
=== Check that referenced BDSes don't inherit ===
--- Configure cache modes on the command line ---
cache.direct=on on blk
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.direct=on on file
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
cache.direct=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
cache.direct=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
cache.writeback=off on blk
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on blk
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on file
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
cache.no-flush=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
--- Cache modes after reopen (live snapshot) ---
cache.direct=on on blk
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.direct=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
cache.direct=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
cache.direct=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
cache.writeback=off on blk
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on blk
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
cache.no-flush=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
--- Change cache modes with reopen (qemu-io command, flags) ---
cache.direct=on on blk
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.direct=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
cache.direct=on on backing
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
cache.direct=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
cache.writeback=off on blk
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing-file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on blk
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on file
Cache mode: writeback, direct
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on backing
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
cache.no-flush=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
=== Reopening children instead of the root ===
--- Basic reopen ---
cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on none0
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.writeback=off on backing
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
cache.writeback=off on backing-file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
cache.no-flush=on on none0
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
--- Change cache mode after reopening child ---
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, ignore flushes
*** done