* [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes()
@ 2019-08-22 16:26 Max Reitz
2019-08-22 16:26 ` [Qemu-devel] [PATCH 1/2] " Max Reitz
` (3 more replies)
0 siblings, 4 replies; 8+ messages in thread
From: Max Reitz @ 2019-08-22 16:26 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Lukáš Doktor, qemu-stable, qemu-devel, Max Reitz
Lukàš ran over a nasty regression in our xfs_write_zeroes() function
(sorry, my fault) made apparent by a recent patch from Anton that makes
qcow2 images heavily exercise the offending code path.
This series fixes the bug and adds a test to prevent it from
reoccurring.
Max Reitz (2):
block/file-posix: Fix xfs_write_zeroes()
iotests: Test reverse sub-cluster qcow2 writes
block/file-posix.c | 16 ++++++---
tests/qemu-iotests/265 | 67 ++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/265.out | 6 ++++
tests/qemu-iotests/group | 1 +
4 files changed, 85 insertions(+), 5 deletions(-)
create mode 100755 tests/qemu-iotests/265
create mode 100644 tests/qemu-iotests/265.out
--
2.21.0
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 1/2] block/file-posix: Fix xfs_write_zeroes()
2019-08-22 16:26 [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Max Reitz
@ 2019-08-22 16:26 ` Max Reitz
2019-08-22 16:26 ` [Qemu-devel] [PATCH 2/2] iotests: Test reverse sub-cluster qcow2 writes Max Reitz
` (2 subsequent siblings)
3 siblings, 0 replies; 8+ messages in thread
From: Max Reitz @ 2019-08-22 16:26 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Lukáš Doktor, qemu-stable, qemu-devel, Max Reitz
Calling ftruncate() in xfs_write_zeroes() is dangerous because it may
yield and then discard data that parallel write requests have written
past the old EOF in the meantime. We must not use it here.
Instead, return -ENOTSUP and let the more generic fallocate code handle
writing zeroes past the EOF.
Reported-by: Lukáš Doktor <ldoktor@redhat.com>
Fixes: 50ba5b2d994853b38fed10e0841b119da0f8b8e5
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
block/file-posix.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index fbeb0068db..b49e0784a4 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1472,10 +1472,13 @@ static int xfs_write_zeroes(BDRVRawState *s, int64_t offset, uint64_t bytes)
}
if (offset + bytes > len) {
- /* XFS_IOC_ZERO_RANGE does not increase the file length */
- if (ftruncate(s->fd, offset + bytes) < 0) {
- return -errno;
- }
+ /*
+ * XFS_IOC_ZERO_RANGE does not increase the file length, but
+ * the caller probably wants us to.
+ * Calling ftruncate() would not be safe, so let the generic
+ * implementation handle this case.
+ */
+ return -ENOTSUP;
}
memset(&fl, 0, sizeof(fl));
@@ -1580,7 +1583,10 @@ static int handle_aiocb_write_zeroes(void *opaque)
#ifdef CONFIG_XFS
if (s->is_xfs) {
- return xfs_write_zeroes(s, aiocb->aio_offset, aiocb->aio_nbytes);
+ int ret = xfs_write_zeroes(s, aiocb->aio_offset, aiocb->aio_nbytes);
+ if (ret != -ENOTSUP) {
+ return ret;
+ }
}
#endif
--
2.21.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 2/2] iotests: Test reverse sub-cluster qcow2 writes
2019-08-22 16:26 [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Max Reitz
2019-08-22 16:26 ` [Qemu-devel] [PATCH 1/2] " Max Reitz
@ 2019-08-22 16:26 ` Max Reitz
2019-08-22 16:53 ` [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Paolo Bonzini
2019-08-23 8:16 ` Anton Nefedov
3 siblings, 0 replies; 8+ messages in thread
From: Max Reitz @ 2019-08-22 16:26 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Lukáš Doktor, qemu-stable, qemu-devel, Max Reitz
This exercises the regression introduced in commit
50ba5b2d994853b38fed10e0841b119da0f8b8e5. On my machine, it has close
to a 50 % false-negative rate, but that should still be sufficient to
test the fix.
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
tests/qemu-iotests/265 | 67 ++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/265.out | 6 ++++
tests/qemu-iotests/group | 1 +
3 files changed, 74 insertions(+)
create mode 100755 tests/qemu-iotests/265
create mode 100644 tests/qemu-iotests/265.out
diff --git a/tests/qemu-iotests/265 b/tests/qemu-iotests/265
new file mode 100755
index 0000000000..dce6f77be3
--- /dev/null
+++ b/tests/qemu-iotests/265
@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+#
+# Test reverse-ordered qcow2 writes on a sub-cluster level
+#
+# Copyright (C) 2019 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/>.
+#
+
+seq=$(basename $0)
+echo "QA output created by $seq"
+
+status=1 # failure is the default!
+
+_cleanup()
+{
+ _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# qcow2-specific test
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+echo '--- Writing to the image ---'
+
+# Reduce cluster size so we get more and quicker I/O
+IMGOPTS='cluster_size=4096' _make_test_img 1M
+(for ((kb = 1024 - 4; kb >= 0; kb -= 4)); do \
+ echo "aio_write -P 42 $((kb + 1))k 2k"; \
+ done) \
+ | $QEMU_IO "$TEST_IMG" > /dev/null
+
+echo '--- Verifying its content ---'
+
+(for ((kb = 0; kb < 1024; kb += 4)); do \
+ echo "read -P 0 ${kb}k 1k"; \
+ echo "read -P 42 $((kb + 1))k 2k"; \
+ echo "read -P 0 $((kb + 3))k 1k"; \
+ done) \
+ | $QEMU_IO "$TEST_IMG" | _filter_qemu_io | grep 'verification'
+
+# Status of qemu-io
+if [ ${PIPESTATUS[1]} = 0 ]; then
+ echo 'Content verified.'
+fi
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/265.out b/tests/qemu-iotests/265.out
new file mode 100644
index 0000000000..6eac620f25
--- /dev/null
+++ b/tests/qemu-iotests/265.out
@@ -0,0 +1,6 @@
+QA output created by 265
+--- Writing to the image ---
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
+--- Verifying its content ---
+Content verified.
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index d95d556414..0c129c1644 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -274,3 +274,4 @@
257 rw
258 rw quick
262 rw quick migration
+265 rw auto quick
--
2.21.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes()
2019-08-22 16:26 [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Max Reitz
2019-08-22 16:26 ` [Qemu-devel] [PATCH 1/2] " Max Reitz
2019-08-22 16:26 ` [Qemu-devel] [PATCH 2/2] iotests: Test reverse sub-cluster qcow2 writes Max Reitz
@ 2019-08-22 16:53 ` Paolo Bonzini
2019-08-22 17:09 ` Max Reitz
2019-08-23 8:16 ` Anton Nefedov
3 siblings, 1 reply; 8+ messages in thread
From: Paolo Bonzini @ 2019-08-22 16:53 UTC (permalink / raw)
To: Max Reitz, qemu-block
Cc: Kevin Wolf, Lukáš Doktor, qemu-stable, qemu-devel
On 22/08/19 18:26, Max Reitz wrote:
> Lukàš ran over a nasty regression in our xfs_write_zeroes() function
> (sorry, my fault) made apparent by a recent patch from Anton that makes
> qcow2 images heavily exercise the offending code path.
>
> This series fixes the bug and adds a test to prevent it from
> reoccurring.
>
>
> Max Reitz (2):
> block/file-posix: Fix xfs_write_zeroes()
> iotests: Test reverse sub-cluster qcow2 writes
>
> block/file-posix.c | 16 ++++++---
> tests/qemu-iotests/265 | 67 ++++++++++++++++++++++++++++++++++++++
> tests/qemu-iotests/265.out | 6 ++++
> tests/qemu-iotests/group | 1 +
> 4 files changed, 85 insertions(+), 5 deletions(-)
> create mode 100755 tests/qemu-iotests/265
> create mode 100644 tests/qemu-iotests/265.out
>
What about just killing libxfs support and only use fallocate?
FALLOC_FL_ZERO_RANGE was added in Linux 3.15 (2014) and the only
platform we probably support with such an old kernel is of course
RHEL/CentOS 7 which has had it backported.
Paolo
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes()
2019-08-22 16:53 ` [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Paolo Bonzini
@ 2019-08-22 17:09 ` Max Reitz
2019-08-23 6:28 ` Lukáš Doktor
0 siblings, 1 reply; 8+ messages in thread
From: Max Reitz @ 2019-08-22 17:09 UTC (permalink / raw)
To: Paolo Bonzini, qemu-block
Cc: Kevin Wolf, Lukáš Doktor, qemu-stable, qemu-devel
On 22.08.19 18:53, Paolo Bonzini wrote:
> On 22/08/19 18:26, Max Reitz wrote:
>> Lukàš ran over a nasty regression in our xfs_write_zeroes() function
>> (sorry, my fault) made apparent by a recent patch from Anton that makes
>> qcow2 images heavily exercise the offending code path.
>>
>> This series fixes the bug and adds a test to prevent it from
>> reoccurring.
>>
>>
>> Max Reitz (2):
>> block/file-posix: Fix xfs_write_zeroes()
>> iotests: Test reverse sub-cluster qcow2 writes
>>
>> block/file-posix.c | 16 ++++++---
>> tests/qemu-iotests/265 | 67 ++++++++++++++++++++++++++++++++++++++
>> tests/qemu-iotests/265.out | 6 ++++
>> tests/qemu-iotests/group | 1 +
>> 4 files changed, 85 insertions(+), 5 deletions(-)
>> create mode 100755 tests/qemu-iotests/265
>> create mode 100644 tests/qemu-iotests/265.out
>>
>
> What about just killing libxfs support and only use fallocate?
> FALLOC_FL_ZERO_RANGE was added in Linux 3.15 (2014) and the only
> platform we probably support with such an old kernel is of course
> RHEL/CentOS 7 which has had it backported.
Works just as well for me. :-)
Max
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes()
2019-08-22 17:09 ` Max Reitz
@ 2019-08-23 6:28 ` Lukáš Doktor
0 siblings, 0 replies; 8+ messages in thread
From: Lukáš Doktor @ 2019-08-23 6:28 UTC (permalink / raw)
To: Max Reitz, Paolo Bonzini, qemu-block
Cc: Kevin Wolf, Anton Nefedov, qemu-stable, qemu-devel
[-- Attachment #1.1: Type: text/plain, Size: 1454 bytes --]
Dne 22. 08. 19 v 19:09 Max Reitz napsal(a):
> On 22.08.19 18:53, Paolo Bonzini wrote:
>> On 22/08/19 18:26, Max Reitz wrote:
>>> Lukàš ran over a nasty regression in our xfs_write_zeroes() function
>>> (sorry, my fault) made apparent by a recent patch from Anton that makes
>>> qcow2 images heavily exercise the offending code path.
>>>
>>> This series fixes the bug and adds a test to prevent it from
>>> reoccurring.
>>>
>>>
>>> Max Reitz (2):
>>> block/file-posix: Fix xfs_write_zeroes()
>>> iotests: Test reverse sub-cluster qcow2 writes
>>>
>>> block/file-posix.c | 16 ++++++---
>>> tests/qemu-iotests/265 | 67 ++++++++++++++++++++++++++++++++++++++
>>> tests/qemu-iotests/265.out | 6 ++++
>>> tests/qemu-iotests/group | 1 +
>>> 4 files changed, 85 insertions(+), 5 deletions(-)
>>> create mode 100755 tests/qemu-iotests/265
>>> create mode 100644 tests/qemu-iotests/265.out
>>>
>>
>> What about just killing libxfs support and only use fallocate?
>> FALLOC_FL_ZERO_RANGE was added in Linux 3.15 (2014) and the only
>> platform we probably support with such an old kernel is of course
>> RHEL/CentOS 7 which has had it backported.
>
> Works just as well for me. :-)
>
> Max
>
Whatever you decide, anyway this patch fixes my arm installation issue and the attached qemu iotest is also passing on my system.
Thank you,
Lukáš
Tested-by: Lukáš Doktor <ldoktor@redhat.com>
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes()
2019-08-22 16:26 [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Max Reitz
` (2 preceding siblings ...)
2019-08-22 16:53 ` [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Paolo Bonzini
@ 2019-08-23 8:16 ` Anton Nefedov
3 siblings, 0 replies; 8+ messages in thread
From: Anton Nefedov @ 2019-08-23 8:16 UTC (permalink / raw)
To: Max Reitz, qemu-block
Cc: Kevin Wolf, Lukáš Doktor, qemu-stable, qemu-devel
On 22/8/2019 7:26 PM, Max Reitz wrote:
> Lukàš ran over a nasty regression in our xfs_write_zeroes() function
> (sorry, my fault) made apparent by a recent patch from Anton that makes
> qcow2 images heavily exercise the offending code path.
>
> This series fixes the bug and adds a test to prevent it from
> reoccurring.
>
>
> Max Reitz (2):
> block/file-posix: Fix xfs_write_zeroes()
> iotests: Test reverse sub-cluster qcow2 writes
>
> block/file-posix.c | 16 ++++++---
> tests/qemu-iotests/265 | 67 ++++++++++++++++++++++++++++++++++++++
> tests/qemu-iotests/265.out | 6 ++++
> tests/qemu-iotests/group | 1 +
> 4 files changed, 85 insertions(+), 5 deletions(-)
> create mode 100755 tests/qemu-iotests/265
> create mode 100644 tests/qemu-iotests/265.out
>
Nice! thanks Max
Reviewed-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 2/2] iotests: Test reverse sub-cluster qcow2 writes
2019-08-23 13:03 [Qemu-devel] [PATCH 0/2] block/file-posix: Reduce xfsctl() use Max Reitz
@ 2019-08-23 13:03 ` Max Reitz
0 siblings, 0 replies; 8+ messages in thread
From: Max Reitz @ 2019-08-23 13:03 UTC (permalink / raw)
To: qemu-block
Cc: Lukáš Doktor, Kevin Wolf, qemu-stable, qemu-devel,
Paolo Bonzini, Max Reitz
This exercises the regression introduced in commit
50ba5b2d994853b38fed10e0841b119da0f8b8e5. On my machine, it has close
to a 50 % false-negative rate, but that should still be sufficient to
test the fix.
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
tests/qemu-iotests/265 | 67 ++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/265.out | 6 ++++
tests/qemu-iotests/group | 1 +
3 files changed, 74 insertions(+)
create mode 100755 tests/qemu-iotests/265
create mode 100644 tests/qemu-iotests/265.out
diff --git a/tests/qemu-iotests/265 b/tests/qemu-iotests/265
new file mode 100755
index 0000000000..dce6f77be3
--- /dev/null
+++ b/tests/qemu-iotests/265
@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+#
+# Test reverse-ordered qcow2 writes on a sub-cluster level
+#
+# Copyright (C) 2019 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/>.
+#
+
+seq=$(basename $0)
+echo "QA output created by $seq"
+
+status=1 # failure is the default!
+
+_cleanup()
+{
+ _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# qcow2-specific test
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+echo '--- Writing to the image ---'
+
+# Reduce cluster size so we get more and quicker I/O
+IMGOPTS='cluster_size=4096' _make_test_img 1M
+(for ((kb = 1024 - 4; kb >= 0; kb -= 4)); do \
+ echo "aio_write -P 42 $((kb + 1))k 2k"; \
+ done) \
+ | $QEMU_IO "$TEST_IMG" > /dev/null
+
+echo '--- Verifying its content ---'
+
+(for ((kb = 0; kb < 1024; kb += 4)); do \
+ echo "read -P 0 ${kb}k 1k"; \
+ echo "read -P 42 $((kb + 1))k 2k"; \
+ echo "read -P 0 $((kb + 3))k 1k"; \
+ done) \
+ | $QEMU_IO "$TEST_IMG" | _filter_qemu_io | grep 'verification'
+
+# Status of qemu-io
+if [ ${PIPESTATUS[1]} = 0 ]; then
+ echo 'Content verified.'
+fi
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/265.out b/tests/qemu-iotests/265.out
new file mode 100644
index 0000000000..6eac620f25
--- /dev/null
+++ b/tests/qemu-iotests/265.out
@@ -0,0 +1,6 @@
+QA output created by 265
+--- Writing to the image ---
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
+--- Verifying its content ---
+Content verified.
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index d95d556414..0c129c1644 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -274,3 +274,4 @@
257 rw
258 rw quick
262 rw quick migration
+265 rw auto quick
--
2.21.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2019-08-23 13:06 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-22 16:26 [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Max Reitz
2019-08-22 16:26 ` [Qemu-devel] [PATCH 1/2] " Max Reitz
2019-08-22 16:26 ` [Qemu-devel] [PATCH 2/2] iotests: Test reverse sub-cluster qcow2 writes Max Reitz
2019-08-22 16:53 ` [Qemu-devel] [PATCH 0/2] block/file-posix: Fix xfs_write_zeroes() Paolo Bonzini
2019-08-22 17:09 ` Max Reitz
2019-08-23 6:28 ` Lukáš Doktor
2019-08-23 8:16 ` Anton Nefedov
2019-08-23 13:03 [Qemu-devel] [PATCH 0/2] block/file-posix: Reduce xfsctl() use Max Reitz
2019-08-23 13:03 ` [Qemu-devel] [PATCH 2/2] iotests: Test reverse sub-cluster qcow2 writes Max Reitz
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).