From: Kevin Wolf <kwolf@redhat.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, vsementsov@virtuozzo.com,
qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com
Subject: [PATCH for-4.2? 0/6] block: Fix resize (extending) of short overlays
Date: Wed, 20 Nov 2019 15:03:13 +0100 [thread overview]
Message-ID: <20191120140319.1505-1-kwolf@redhat.com> (raw)
Consider the following scenario where the overlay is shorter than its
backing file:
base.qcow2: AAAAAAAA
overlay.qcow2: BBBB
When resizing (extending) overlay.qcow2, the new blocks should not stay
unallocated and make the additional As from base.qcow2 visible like
before this series, but zeros should be read.
A similar case happens with the various variants of a commit job when an
intermediate file is short (- for unallocated):
base.qcow2: A-A-AAAA
mid.qcow2: BB-B
top.qcow2: C--C--C-
After commit top.qcow2 to mid.qcow2, the following happens:
mid.qcow2: CB-C00C0 (correct result)
mid.qcow2: CB-C--C- (before this fix)
Without the fix, blocks that previously read as zeros on top.qcow2
suddenly turn into A.
Kevin Wolf (6):
block: bdrv_co_do_pwrite_zeroes: 64 bit 'bytes' parameter
block: truncate: Don't make backing file data visible
iotests: Add qemu_io_log()
iotests: Fix timeout in run_job()
iotests: Support job-complete in run_job()
iotests: Test committing to short backing file
block/io.c | 31 ++++++-
tests/qemu-iotests/274 | 131 +++++++++++++++++++++++++++++
tests/qemu-iotests/274.out | 150 ++++++++++++++++++++++++++++++++++
tests/qemu-iotests/group | 1 +
tests/qemu-iotests/iotests.py | 11 ++-
5 files changed, 319 insertions(+), 5 deletions(-)
create mode 100755 tests/qemu-iotests/274
create mode 100644 tests/qemu-iotests/274.out
--
2.20.1
next reply other threads:[~2019-11-20 14:05 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-20 14:03 Kevin Wolf [this message]
2019-11-20 14:03 ` [PATCH 1/6] block: bdrv_co_do_pwrite_zeroes: 64 bit 'bytes' parameter Kevin Wolf
2019-11-20 14:14 ` Eric Blake
2019-11-20 14:27 ` Vladimir Sementsov-Ogievskiy
2019-11-20 16:18 ` Alberto Garcia
2019-11-20 14:03 ` [PATCH 2/6] block: truncate: Don't make backing file data visible Kevin Wolf
2019-11-20 14:20 ` Eric Blake
2019-11-20 14:47 ` Vladimir Sementsov-Ogievskiy
2019-11-20 15:12 ` Kevin Wolf
2019-11-20 18:01 ` Vladimir Sementsov-Ogievskiy
2019-11-25 11:06 ` Kevin Wolf
2019-11-20 14:03 ` [PATCH 3/6] iotests: Add qemu_io_log() Kevin Wolf
2019-11-20 14:26 ` Eric Blake
2019-11-20 14:49 ` Vladimir Sementsov-Ogievskiy
2019-11-20 14:03 ` [PATCH 4/6] iotests: Fix timeout in run_job() Kevin Wolf
2019-11-20 14:29 ` Eric Blake
2019-11-20 14:51 ` Vladimir Sementsov-Ogievskiy
2019-11-20 14:03 ` [PATCH 5/6] iotests: Support job-complete " Kevin Wolf
2019-11-20 14:46 ` Eric Blake
2019-11-20 14:56 ` Vladimir Sementsov-Ogievskiy
2019-11-20 14:03 ` [PATCH 6/6] iotests: Test committing to short backing file Kevin Wolf
2019-11-20 14:52 ` Eric Blake
2019-11-20 15:41 ` Vladimir Sementsov-Ogievskiy
2019-11-20 16:11 ` Kevin Wolf
2019-11-20 16:29 ` Vladimir Sementsov-Ogievskiy
2019-11-20 16:10 ` Vladimir Sementsov-Ogievskiy
2019-11-20 15:49 ` [PATCH for-4.2? 0/6] block: Fix resize (extending) of short overlays Vladimir Sementsov-Ogievskiy
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