[PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

Test writing into a file range containing prealloc extents beyond the current
i_size, with an unmount and mount after fallocate and the write, to verify
that the file data, size and extent layout were not lost.

This used to fail on btrfs when not using the no-holes feature (which is
a default since btrfs-progs 5.15) before this recent kernel fix:

   080ecbd05432 ("btrfs: mark file extent range dirty after converting prealloc extents")

So in order to reproduce the failure when using an unpatched kernel and
a btrfs-progs >= 5.15, one must run the test with:

   MKFS_OPTIONS="-O ^no-holes"

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 tests/generic/796     | 54 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/796.out | 10 ++++++++
 2 files changed, 64 insertions(+)
 create mode 100755 tests/generic/796
 create mode 100644 tests/generic/796.out

diff --git a/tests/generic/796 b/tests/generic/796
new file mode 100755
index 00000000..c42a4722
--- /dev/null
+++ b/tests/generic/796
@@ -0,0 +1,54 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
+#
+# FS QA Test 796
+#
+# Test writing into a file range containing prealloc extents beyond the current
+# i_size, with an unmount and mount after fallocate and the write, to verify
+# that the file data, size and extent layout were not lost.
+#
+. ./common/preamble
+_begin_fstest auto quick prealloc preallocrw fiemap
+
+. ./common/filter
+. ./common/punch # for _filter_fiemap
+
+_require_scratch
+_require_xfs_io_command "falloc" "-k"
+_require_xfs_io_command "fiemap"
+
+_fixed_by_fs_commit btrfs 080ecbd05432 \
+	"btrfs: mark file extent range dirty after converting prealloc extents"
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+# The fiemap results in the golden output requires file allocations to align to
+# 1M boundaries.
+_require_congruent_file_oplen $SCRATCH_MNT 1048576
+
+# Create our file with a size of 0 and a prealloc extent in the range [0, 2M].
+$XFS_IO_PROG -f -c "falloc -k 0 2M" $SCRATCH_MNT/foo
+
+# Unmount and mount again to remove any in memory state of the inode. We will
+# verify later that neither metadata nor extents were lost during unmount.
+_scratch_cycle_mount
+
+# Write into the [0, 1M] range, which increases the inode's i_size.
+$XFS_IO_PROG -c "pwrite -S 0xab -b 1M 0 1M" $SCRATCH_MNT/foo | _filter_xfs_io
+
+# Unmount and mount again to remove any in memory state of the inode. We will
+# verify later that neither metadata nor extents were lost during unmount.
+_scratch_cycle_mount
+
+# Check file data (and size).
+echo "File data:"
+_hexdump $SCRATCH_MNT/foo
+
+# Check we have unwritten extents in range [1M, 2M].
+echo "Fiemap output:"
+$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap
+
+# Success, all done.
+_exit 0
diff --git a/tests/generic/796.out b/tests/generic/796.out
new file mode 100644
index 00000000..c6c6e6a8
--- /dev/null
+++ b/tests/generic/796.out
@@ -0,0 +1,10 @@
+QA output created by 796
+wrote 1048576/1048576 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+File data:
+000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab  >................<
+*
+100000
+Fiemap output:
+0: [0..2047]: data
+1: [2048..4095]: unwritten
-- 
2.47.2

Re: [PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[Qu Wenruo]

在 2026/5/28 19:57, fdmanana@kernel.org 写道:
> From: Filipe Manana <fdmanana@suse.com>
> 
> Test writing into a file range containing prealloc extents beyond the current
> i_size, with an unmount and mount after fallocate and the write, to verify
> that the file data, size and extent layout were not lost.
> 
> This used to fail on btrfs when not using the no-holes feature (which is
> a default since btrfs-progs 5.15) before this recent kernel fix:
> 
>     080ecbd05432 ("btrfs: mark file extent range dirty after converting prealloc extents")
> 
> So in order to reproduce the failure when using an unpatched kernel and
> a btrfs-progs >= 5.15, one must run the test with:
> 
>     MKFS_OPTIONS="-O ^no-holes"
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Reviewed-by: Qu Wenruo <wqu@suse.com>


Just one question related to the specified mkfs option.

As you mentioned, this bug is only affecting ^no-holes, thus default 
mount option runs won't trigger it.

This makes me wondering, should we have a dedicated btrfs test case just 
exercising the ^no-holes path.

I know this will cause duplication, thus will not be a good idea to 
maintain, but we also have dedicated test cases utilizing specified 
mount option/mkfs options already.

So what is the prefer method here?

Thanks,
Qu
> ---
>   tests/generic/796     | 54 +++++++++++++++++++++++++++++++++++++++++++
>   tests/generic/796.out | 10 ++++++++
>   2 files changed, 64 insertions(+)
>   create mode 100755 tests/generic/796
>   create mode 100644 tests/generic/796.out
> 
> diff --git a/tests/generic/796 b/tests/generic/796
> new file mode 100755
> index 00000000..c42a4722
> --- /dev/null
> +++ b/tests/generic/796
> @@ -0,0 +1,54 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
> +#
> +# FS QA Test 796
> +#
> +# Test writing into a file range containing prealloc extents beyond the current
> +# i_size, with an unmount and mount after fallocate and the write, to verify
> +# that the file data, size and extent layout were not lost.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick prealloc preallocrw fiemap
> +
> +. ./common/filter
> +. ./common/punch # for _filter_fiemap
> +
> +_require_scratch
> +_require_xfs_io_command "falloc" "-k"
> +_require_xfs_io_command "fiemap"
> +
> +_fixed_by_fs_commit btrfs 080ecbd05432 \
> +	"btrfs: mark file extent range dirty after converting prealloc extents"
> +
> +_scratch_mkfs >>$seqres.full 2>&1
> +_scratch_mount
> +
> +# The fiemap results in the golden output requires file allocations to align to
> +# 1M boundaries.
> +_require_congruent_file_oplen $SCRATCH_MNT 1048576
> +
> +# Create our file with a size of 0 and a prealloc extent in the range [0, 2M].
> +$XFS_IO_PROG -f -c "falloc -k 0 2M" $SCRATCH_MNT/foo
> +
> +# Unmount and mount again to remove any in memory state of the inode. We will
> +# verify later that neither metadata nor extents were lost during unmount.
> +_scratch_cycle_mount
> +
> +# Write into the [0, 1M] range, which increases the inode's i_size.
> +$XFS_IO_PROG -c "pwrite -S 0xab -b 1M 0 1M" $SCRATCH_MNT/foo | _filter_xfs_io
> +
> +# Unmount and mount again to remove any in memory state of the inode. We will
> +# verify later that neither metadata nor extents were lost during unmount.
> +_scratch_cycle_mount
> +
> +# Check file data (and size).
> +echo "File data:"
> +_hexdump $SCRATCH_MNT/foo
> +
> +# Check we have unwritten extents in range [1M, 2M].
> +echo "Fiemap output:"
> +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap
> +
> +# Success, all done.
> +_exit 0
> diff --git a/tests/generic/796.out b/tests/generic/796.out
> new file mode 100644
> index 00000000..c6c6e6a8
> --- /dev/null
> +++ b/tests/generic/796.out
> @@ -0,0 +1,10 @@
> +QA output created by 796
> +wrote 1048576/1048576 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +File data:
> +000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab  >................<
> +*
> +100000
> +Fiemap output:
> +0: [0..2047]: data
> +1: [2048..4095]: unwritten

Re: [PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[Filipe Manana]

On Thu, May 28, 2026 at 12:23 PM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>
>
>
> 在 2026/5/28 19:57, fdmanana@kernel.org 写道:
> > From: Filipe Manana <fdmanana@suse.com>
> >
> > Test writing into a file range containing prealloc extents beyond the current
> > i_size, with an unmount and mount after fallocate and the write, to verify
> > that the file data, size and extent layout were not lost.
> >
> > This used to fail on btrfs when not using the no-holes feature (which is
> > a default since btrfs-progs 5.15) before this recent kernel fix:
> >
> >     080ecbd05432 ("btrfs: mark file extent range dirty after converting prealloc extents")
> >
> > So in order to reproduce the failure when using an unpatched kernel and
> > a btrfs-progs >= 5.15, one must run the test with:
> >
> >     MKFS_OPTIONS="-O ^no-holes"
> >
> > Signed-off-by: Filipe Manana <fdmanana@suse.com>
>
> Reviewed-by: Qu Wenruo <wqu@suse.com>
>
>
> Just one question related to the specified mkfs option.
>
> As you mentioned, this bug is only affecting ^no-holes, thus default
> mount option runs won't trigger it.
>
> This makes me wondering, should we have a dedicated btrfs test case just
> exercising the ^no-holes path.
>
> I know this will cause duplication, thus will not be a good idea to
> maintain, but we also have dedicated test cases utilizing specified
> mount option/mkfs options already.
>
> So what is the prefer method here?

So in the past I attempted tests like that, making them btrfs specific
and forcing a mount option.
Some people (non-btrfs people, I don't recall exactly who, to be
honest) disagreed with the claims that the test was actually generic,
and that exercising the bug should be done by setting MKFS_OPTIONS in
the command line.

I'm assuming people and our automations run tests with -O ^no-holes. I
do it frequently in my test vms.

>
> Thanks,
> Qu
> > ---
> >   tests/generic/796     | 54 +++++++++++++++++++++++++++++++++++++++++++
> >   tests/generic/796.out | 10 ++++++++
> >   2 files changed, 64 insertions(+)
> >   create mode 100755 tests/generic/796
> >   create mode 100644 tests/generic/796.out
> >
> > diff --git a/tests/generic/796 b/tests/generic/796
> > new file mode 100755
> > index 00000000..c42a4722
> > --- /dev/null
> > +++ b/tests/generic/796
> > @@ -0,0 +1,54 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
> > +#
> > +# FS QA Test 796
> > +#
> > +# Test writing into a file range containing prealloc extents beyond the current
> > +# i_size, with an unmount and mount after fallocate and the write, to verify
> > +# that the file data, size and extent layout were not lost.
> > +#
> > +. ./common/preamble
> > +_begin_fstest auto quick prealloc preallocrw fiemap
> > +
> > +. ./common/filter
> > +. ./common/punch # for _filter_fiemap
> > +
> > +_require_scratch
> > +_require_xfs_io_command "falloc" "-k"
> > +_require_xfs_io_command "fiemap"
> > +
> > +_fixed_by_fs_commit btrfs 080ecbd05432 \
> > +     "btrfs: mark file extent range dirty after converting prealloc extents"
> > +
> > +_scratch_mkfs >>$seqres.full 2>&1
> > +_scratch_mount
> > +
> > +# The fiemap results in the golden output requires file allocations to align to
> > +# 1M boundaries.
> > +_require_congruent_file_oplen $SCRATCH_MNT 1048576
> > +
> > +# Create our file with a size of 0 and a prealloc extent in the range [0, 2M].
> > +$XFS_IO_PROG -f -c "falloc -k 0 2M" $SCRATCH_MNT/foo
> > +
> > +# Unmount and mount again to remove any in memory state of the inode. We will
> > +# verify later that neither metadata nor extents were lost during unmount.
> > +_scratch_cycle_mount
> > +
> > +# Write into the [0, 1M] range, which increases the inode's i_size.
> > +$XFS_IO_PROG -c "pwrite -S 0xab -b 1M 0 1M" $SCRATCH_MNT/foo | _filter_xfs_io
> > +
> > +# Unmount and mount again to remove any in memory state of the inode. We will
> > +# verify later that neither metadata nor extents were lost during unmount.
> > +_scratch_cycle_mount
> > +
> > +# Check file data (and size).
> > +echo "File data:"
> > +_hexdump $SCRATCH_MNT/foo
> > +
> > +# Check we have unwritten extents in range [1M, 2M].
> > +echo "Fiemap output:"
> > +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap
> > +
> > +# Success, all done.
> > +_exit 0
> > diff --git a/tests/generic/796.out b/tests/generic/796.out
> > new file mode 100644
> > index 00000000..c6c6e6a8
> > --- /dev/null
> > +++ b/tests/generic/796.out
> > @@ -0,0 +1,10 @@
> > +QA output created by 796
> > +wrote 1048576/1048576 bytes at offset 0
> > +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> > +File data:
> > +000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab  >................<
> > +*
> > +100000
> > +Fiemap output:
> > +0: [0..2047]: data
> > +1: [2048..4095]: unwritten
>

Re: [PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[Anand Jain]

On 28/5/26 19:30, Filipe Manana wrote:
> On Thu, May 28, 2026 at 12:23 PM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>>
>>
>>
>> 在 2026/5/28 19:57, fdmanana@kernel.org 写道:
>>> From: Filipe Manana <fdmanana@suse.com>
>>>
>>> Test writing into a file range containing prealloc extents beyond the current
>>> i_size, with an unmount and mount after fallocate and the write, to verify
>>> that the file data, size and extent layout were not lost.
>>>
>>> This used to fail on btrfs when not using the no-holes feature (which is
>>> a default since btrfs-progs 5.15) before this recent kernel fix:
>>>
>>>     080ecbd05432 ("btrfs: mark file extent range dirty after converting prealloc extents")
>>>
>>> So in order to reproduce the failure when using an unpatched kernel and
>>> a btrfs-progs >= 5.15, one must run the test with:
>>>
>>>     MKFS_OPTIONS="-O ^no-holes"
>>>
>>> Signed-off-by: Filipe Manana <fdmanana@suse.com>
>>
>> Reviewed-by: Qu Wenruo <wqu@suse.com>
>>
>>
>> Just one question related to the specified mkfs option.
>>
>> As you mentioned, this bug is only affecting ^no-holes, thus default
>> mount option runs won't trigger it.
>>
>> This makes me wondering, should we have a dedicated btrfs test case just
>> exercising the ^no-holes path.
>>
>> I know this will cause duplication, thus will not be a good idea to
>> maintain, but we also have dedicated test cases utilizing specified
>> mount option/mkfs options already.
>>
>> So what is the prefer method here?
> 

There will be many testcase and option combinations,
which makes this harder to scale and increases the
chances of missing a testcase + option combination
across federated teams.

I think it makes sense to maintain a standard testing config
(not sure what to call it, maybe a Test-Profile?).

V2 was sent here:

https://lore.kernel.org/fstests/cfb8c19533ac3c764edc1fe62b7fde75e76579a4.1743137470.git.anand.jain@oracle.com/

Any thoughts? I'm ok to revisit to send v3 if needed.

Thanks, Anand


> So in the past I attempted tests like that, making them btrfs specific
> and forcing a mount option.
> Some people (non-btrfs people, I don't recall exactly who, to be
> honest) disagreed with the claims that the test was actually generic,
> and that exercising the bug should be done by setting MKFS_OPTIONS in
> the command line.
> 
> I'm assuming people and our automations run tests with -O ^no-holes. I
> do it frequently in my test vms.
> 
>>
>> Thanks,
>> Qu
>>> ---
>>>   tests/generic/796     | 54 +++++++++++++++++++++++++++++++++++++++++++
>>>   tests/generic/796.out | 10 ++++++++
>>>   2 files changed, 64 insertions(+)
>>>   create mode 100755 tests/generic/796
>>>   create mode 100644 tests/generic/796.out
>>>
>>> diff --git a/tests/generic/796 b/tests/generic/796
>>> new file mode 100755
>>> index 00000000..c42a4722
>>> --- /dev/null
>>> +++ b/tests/generic/796
>>> @@ -0,0 +1,54 @@
>>> +#! /bin/bash
>>> +# SPDX-License-Identifier: GPL-2.0
>>> +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
>>> +#
>>> +# FS QA Test 796
>>> +#
>>> +# Test writing into a file range containing prealloc extents beyond the current
>>> +# i_size, with an unmount and mount after fallocate and the write, to verify
>>> +# that the file data, size and extent layout were not lost.
>>> +#
>>> +. ./common/preamble
>>> +_begin_fstest auto quick prealloc preallocrw fiemap
>>> +
>>> +. ./common/filter
>>> +. ./common/punch # for _filter_fiemap
>>> +
>>> +_require_scratch
>>> +_require_xfs_io_command "falloc" "-k"
>>> +_require_xfs_io_command "fiemap"
>>> +
>>> +_fixed_by_fs_commit btrfs 080ecbd05432 \
>>> +     "btrfs: mark file extent range dirty after converting prealloc extents"
>>> +
>>> +_scratch_mkfs >>$seqres.full 2>&1
>>> +_scratch_mount
>>> +
>>> +# The fiemap results in the golden output requires file allocations to align to
>>> +# 1M boundaries.
>>> +_require_congruent_file_oplen $SCRATCH_MNT 1048576
>>> +
>>> +# Create our file with a size of 0 and a prealloc extent in the range [0, 2M].
>>> +$XFS_IO_PROG -f -c "falloc -k 0 2M" $SCRATCH_MNT/foo
>>> +
>>> +# Unmount and mount again to remove any in memory state of the inode. We will
>>> +# verify later that neither metadata nor extents were lost during unmount.
>>> +_scratch_cycle_mount
>>> +
>>> +# Write into the [0, 1M] range, which increases the inode's i_size.
>>> +$XFS_IO_PROG -c "pwrite -S 0xab -b 1M 0 1M" $SCRATCH_MNT/foo | _filter_xfs_io
>>> +
>>> +# Unmount and mount again to remove any in memory state of the inode. We will
>>> +# verify later that neither metadata nor extents were lost during unmount.
>>> +_scratch_cycle_mount
>>> +
>>> +# Check file data (and size).
>>> +echo "File data:"
>>> +_hexdump $SCRATCH_MNT/foo
>>> +
>>> +# Check we have unwritten extents in range [1M, 2M].
>>> +echo "Fiemap output:"
>>> +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap
>>> +
>>> +# Success, all done.
>>> +_exit 0
>>> diff --git a/tests/generic/796.out b/tests/generic/796.out
>>> new file mode 100644
>>> index 00000000..c6c6e6a8
>>> --- /dev/null
>>> +++ b/tests/generic/796.out
>>> @@ -0,0 +1,10 @@
>>> +QA output created by 796
>>> +wrote 1048576/1048576 bytes at offset 0
>>> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
>>> +File data:
>>> +000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab  >................<
>>> +*
>>> +100000
>>> +Fiemap output:
>>> +0: [0..2047]: data
>>> +1: [2048..4095]: unwritten
>>

Re: [PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[Qu Wenruo]

在 2026/5/29 09:22, Anand Jain 写道:
> On 28/5/26 19:30, Filipe Manana wrote:
>> On Thu, May 28, 2026 at 12:23 PM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>>>
>>>
>>>
>>> 在 2026/5/28 19:57, fdmanana@kernel.org 写道:
>>>> From: Filipe Manana <fdmanana@suse.com>
>>>>
>>>> Test writing into a file range containing prealloc extents beyond the current
>>>> i_size, with an unmount and mount after fallocate and the write, to verify
>>>> that the file data, size and extent layout were not lost.
>>>>
>>>> This used to fail on btrfs when not using the no-holes feature (which is
>>>> a default since btrfs-progs 5.15) before this recent kernel fix:
>>>>
>>>>      080ecbd05432 ("btrfs: mark file extent range dirty after converting prealloc extents")
>>>>
>>>> So in order to reproduce the failure when using an unpatched kernel and
>>>> a btrfs-progs >= 5.15, one must run the test with:
>>>>
>>>>      MKFS_OPTIONS="-O ^no-holes"
>>>>
>>>> Signed-off-by: Filipe Manana <fdmanana@suse.com>
>>>
>>> Reviewed-by: Qu Wenruo <wqu@suse.com>
>>>
>>>
>>> Just one question related to the specified mkfs option.
>>>
>>> As you mentioned, this bug is only affecting ^no-holes, thus default
>>> mount option runs won't trigger it.
>>>
>>> This makes me wondering, should we have a dedicated btrfs test case just
>>> exercising the ^no-holes path.
>>>
>>> I know this will cause duplication, thus will not be a good idea to
>>> maintain, but we also have dedicated test cases utilizing specified
>>> mount option/mkfs options already.
>>>
>>> So what is the prefer method here?
>>
> 
> There will be many testcase and option combinations,
> which makes this harder to scale and increases the
> chances of missing a testcase + option combination
> across federated teams.
> 
> I think it makes sense to maintain a standard testing config
> (not sure what to call it, maybe a Test-Profile?).
> 
> V2 was sent here:
> 
> https://lore.kernel.org/fstests/cfb8c19533ac3c764edc1fe62b7fde75e76579a4.1743137470.git.anand.jain@oracle.com/
> 
> Any thoughts? I'm ok to revisit to send v3 if needed.

There is no "nodatasum" mount option to verify the behavior of zero-copy 
direct writes.
Although I hope the incoming IOMAP_DIO_BOUNCE flag usage will get rid of 
the special nodatasum requirement for dio.

Nor "flushoncommit" mount option which recently exposed a deadlock.

And I'm not sure if you should put "rst" mkfs option as default, it's 
still very experimental.

Not to mention there will be more and more sectorsize/nodesize 
combination to come with bs > ps support, or on 64K page sizes systems.
Meanwhile the coverage itself may not be improved that much with extra 
sectorsizes...

Finally you're pushing for a lot of compression runs (3 out of 8), but 
IIRC there are some known failures and some ENOSPC runs will take way 
too longer than regular runs.

Even with a 24x7 VM running tests, the generated false alerts still will 
take a lot of human time to review and fix.

> 
> Thanks, Anand
> 
> 
>> So in the past I attempted tests like that, making them btrfs specific
>> and forcing a mount option.
>> Some people (non-btrfs people, I don't recall exactly who, to be
>> honest) disagreed with the claims that the test was actually generic,
>> and that exercising the bug should be done by setting MKFS_OPTIONS in
>> the command line.
>>
>> I'm assuming people and our automations run tests with -O ^no-holes. I
>> do it frequently in my test vms.
>>
>>>
>>> Thanks,
>>> Qu
>>>> ---
>>>>    tests/generic/796     | 54 +++++++++++++++++++++++++++++++++++++++++++
>>>>    tests/generic/796.out | 10 ++++++++
>>>>    2 files changed, 64 insertions(+)
>>>>    create mode 100755 tests/generic/796
>>>>    create mode 100644 tests/generic/796.out
>>>>
>>>> diff --git a/tests/generic/796 b/tests/generic/796
>>>> new file mode 100755
>>>> index 00000000..c42a4722
>>>> --- /dev/null
>>>> +++ b/tests/generic/796
>>>> @@ -0,0 +1,54 @@
>>>> +#! /bin/bash
>>>> +# SPDX-License-Identifier: GPL-2.0
>>>> +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
>>>> +#
>>>> +# FS QA Test 796
>>>> +#
>>>> +# Test writing into a file range containing prealloc extents beyond the current
>>>> +# i_size, with an unmount and mount after fallocate and the write, to verify
>>>> +# that the file data, size and extent layout were not lost.
>>>> +#
>>>> +. ./common/preamble
>>>> +_begin_fstest auto quick prealloc preallocrw fiemap
>>>> +
>>>> +. ./common/filter
>>>> +. ./common/punch # for _filter_fiemap
>>>> +
>>>> +_require_scratch
>>>> +_require_xfs_io_command "falloc" "-k"
>>>> +_require_xfs_io_command "fiemap"
>>>> +
>>>> +_fixed_by_fs_commit btrfs 080ecbd05432 \
>>>> +     "btrfs: mark file extent range dirty after converting prealloc extents"
>>>> +
>>>> +_scratch_mkfs >>$seqres.full 2>&1
>>>> +_scratch_mount
>>>> +
>>>> +# The fiemap results in the golden output requires file allocations to align to
>>>> +# 1M boundaries.
>>>> +_require_congruent_file_oplen $SCRATCH_MNT 1048576
>>>> +
>>>> +# Create our file with a size of 0 and a prealloc extent in the range [0, 2M].
>>>> +$XFS_IO_PROG -f -c "falloc -k 0 2M" $SCRATCH_MNT/foo
>>>> +
>>>> +# Unmount and mount again to remove any in memory state of the inode. We will
>>>> +# verify later that neither metadata nor extents were lost during unmount.
>>>> +_scratch_cycle_mount
>>>> +
>>>> +# Write into the [0, 1M] range, which increases the inode's i_size.
>>>> +$XFS_IO_PROG -c "pwrite -S 0xab -b 1M 0 1M" $SCRATCH_MNT/foo | _filter_xfs_io
>>>> +
>>>> +# Unmount and mount again to remove any in memory state of the inode. We will
>>>> +# verify later that neither metadata nor extents were lost during unmount.
>>>> +_scratch_cycle_mount
>>>> +
>>>> +# Check file data (and size).
>>>> +echo "File data:"
>>>> +_hexdump $SCRATCH_MNT/foo
>>>> +
>>>> +# Check we have unwritten extents in range [1M, 2M].
>>>> +echo "Fiemap output:"
>>>> +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap
>>>> +
>>>> +# Success, all done.
>>>> +_exit 0
>>>> diff --git a/tests/generic/796.out b/tests/generic/796.out
>>>> new file mode 100644
>>>> index 00000000..c6c6e6a8
>>>> --- /dev/null
>>>> +++ b/tests/generic/796.out
>>>> @@ -0,0 +1,10 @@
>>>> +QA output created by 796
>>>> +wrote 1048576/1048576 bytes at offset 0
>>>> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
>>>> +File data:
>>>> +000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab  >................<
>>>> +*
>>>> +100000
>>>> +Fiemap output:
>>>> +0: [0..2047]: data
>>>> +1: [2048..4095]: unwritten
>>>
> 
> 

Re: [PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[Filipe Manana]

On Thu, May 28, 2026 at 11:27 AM <fdmanana@kernel.org> wrote:
>
> From: Filipe Manana <fdmanana@suse.com>
>
> Test writing into a file range containing prealloc extents beyond the current
> i_size, with an unmount and mount after fallocate and the write, to verify
> that the file data, size and extent layout were not lost.
>
> This used to fail on btrfs when not using the no-holes feature (which is
> a default since btrfs-progs 5.15) before this recent kernel fix:
>
>    080ecbd05432 ("btrfs: mark file extent range dirty after converting prealloc extents")
>
> So in order to reproduce the failure when using an unpatched kernel and
> a btrfs-progs >= 5.15, one must run the test with:
>
>    MKFS_OPTIONS="-O ^no-holes"
>
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Zorro, this is missing in the patches-in-queue branch (and for-next).
Did you miss this?

Thanks.

> ---
>  tests/generic/796     | 54 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/796.out | 10 ++++++++
>  2 files changed, 64 insertions(+)
>  create mode 100755 tests/generic/796
>  create mode 100644 tests/generic/796.out
>
> diff --git a/tests/generic/796 b/tests/generic/796
> new file mode 100755
> index 00000000..c42a4722
> --- /dev/null
> +++ b/tests/generic/796
> @@ -0,0 +1,54 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
> +#
> +# FS QA Test 796
> +#
> +# Test writing into a file range containing prealloc extents beyond the current
> +# i_size, with an unmount and mount after fallocate and the write, to verify
> +# that the file data, size and extent layout were not lost.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick prealloc preallocrw fiemap
> +
> +. ./common/filter
> +. ./common/punch # for _filter_fiemap
> +
> +_require_scratch
> +_require_xfs_io_command "falloc" "-k"
> +_require_xfs_io_command "fiemap"
> +
> +_fixed_by_fs_commit btrfs 080ecbd05432 \
> +       "btrfs: mark file extent range dirty after converting prealloc extents"
> +
> +_scratch_mkfs >>$seqres.full 2>&1
> +_scratch_mount
> +
> +# The fiemap results in the golden output requires file allocations to align to
> +# 1M boundaries.
> +_require_congruent_file_oplen $SCRATCH_MNT 1048576
> +
> +# Create our file with a size of 0 and a prealloc extent in the range [0, 2M].
> +$XFS_IO_PROG -f -c "falloc -k 0 2M" $SCRATCH_MNT/foo
> +
> +# Unmount and mount again to remove any in memory state of the inode. We will
> +# verify later that neither metadata nor extents were lost during unmount.
> +_scratch_cycle_mount
> +
> +# Write into the [0, 1M] range, which increases the inode's i_size.
> +$XFS_IO_PROG -c "pwrite -S 0xab -b 1M 0 1M" $SCRATCH_MNT/foo | _filter_xfs_io
> +
> +# Unmount and mount again to remove any in memory state of the inode. We will
> +# verify later that neither metadata nor extents were lost during unmount.
> +_scratch_cycle_mount
> +
> +# Check file data (and size).
> +echo "File data:"
> +_hexdump $SCRATCH_MNT/foo
> +
> +# Check we have unwritten extents in range [1M, 2M].
> +echo "Fiemap output:"
> +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap
> +
> +# Success, all done.
> +_exit 0
> diff --git a/tests/generic/796.out b/tests/generic/796.out
> new file mode 100644
> index 00000000..c6c6e6a8
> --- /dev/null
> +++ b/tests/generic/796.out
> @@ -0,0 +1,10 @@
> +QA output created by 796
> +wrote 1048576/1048576 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +File data:
> +000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab  >................<
> +*
> +100000
> +Fiemap output:
> +0: [0..2047]: data
> +1: [2048..4095]: unwritten
> --
> 2.47.2
>
>

Re: [PATCH] generic: add a test case for writes with prealloc extents beyond i_size

[Zorro Lang]

On Sun, Jun 14, 2026 at 11:57:39AM +0100, Filipe Manana wrote:
> On Thu, May 28, 2026 at 11:27 AM <fdmanana@kernel.org> wrote:
> >
> > From: Filipe Manana <fdmanana@suse.com>
> >
> > Test writing into a file range containing prealloc extents beyond the current
> > i_size, with an unmount and mount after fallocate and the write, to verify
> > that the file data, size and extent layout were not lost.
> >
> > This used to fail on btrfs when not using the no-holes feature (which is
> > a default since btrfs-progs 5.15) before this recent kernel fix:
> >
> >    080ecbd05432 ("btrfs: mark file extent range dirty after converting prealloc extents")
> >
> > So in order to reproduce the failure when using an unpatched kernel and
> > a btrfs-progs >= 5.15, one must run the test with:
> >
> >    MKFS_OPTIONS="-O ^no-holes"
> >
> > Signed-off-by: Filipe Manana <fdmanana@suse.com>
> 
> Zorro, this is missing in the patches-in-queue branch (and for-next).
> Did you miss this?

Hi Filipe,

Sorry, I got this patch mixed up with another one -- 32b4dfff ("generic: add a
test case for fallocate i_size extension"). They have the same author, reviewer,
and case number, and even their commit logs look very similar. At first glance,
I mistakenly thought it was a patch I had already merged :-P

Thank you for pointing this out. I will test it and merge it into the
patches-in-queue branch right away, and it will be released next week
along with the others.

Thanks,
Zorro

> 
> Thanks.
> 
> > ---
> >  tests/generic/796     | 54 +++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/796.out | 10 ++++++++
> >  2 files changed, 64 insertions(+)
> >  create mode 100755 tests/generic/796
> >  create mode 100644 tests/generic/796.out
> >
> > diff --git a/tests/generic/796 b/tests/generic/796
> > new file mode 100755
> > index 00000000..c42a4722
> > --- /dev/null
> > +++ b/tests/generic/796
> > @@ -0,0 +1,54 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2026 SUSE S.A.  All Rights Reserved.
> > +#
> > +# FS QA Test 796
> > +#
> > +# Test writing into a file range containing prealloc extents beyond the current
> > +# i_size, with an unmount and mount after fallocate and the write, to verify
> > +# that the file data, size and extent layout were not lost.
> > +#
> > +. ./common/preamble
> > +_begin_fstest auto quick prealloc preallocrw fiemap
> > +
> > +. ./common/filter
> > +. ./common/punch # for _filter_fiemap
> > +
> > +_require_scratch
> > +_require_xfs_io_command "falloc" "-k"
> > +_require_xfs_io_command "fiemap"
> > +
> > +_fixed_by_fs_commit btrfs 080ecbd05432 \
> > +       "btrfs: mark file extent range dirty after converting prealloc extents"
> > +
> > +_scratch_mkfs >>$seqres.full 2>&1
> > +_scratch_mount
> > +
> > +# The fiemap results in the golden output requires file allocations to align to
> > +# 1M boundaries.
> > +_require_congruent_file_oplen $SCRATCH_MNT 1048576
> > +
> > +# Create our file with a size of 0 and a prealloc extent in the range [0, 2M].
> > +$XFS_IO_PROG -f -c "falloc -k 0 2M" $SCRATCH_MNT/foo
> > +
> > +# Unmount and mount again to remove any in memory state of the inode. We will
> > +# verify later that neither metadata nor extents were lost during unmount.
> > +_scratch_cycle_mount
> > +
> > +# Write into the [0, 1M] range, which increases the inode's i_size.
> > +$XFS_IO_PROG -c "pwrite -S 0xab -b 1M 0 1M" $SCRATCH_MNT/foo | _filter_xfs_io
> > +
> > +# Unmount and mount again to remove any in memory state of the inode. We will
> > +# verify later that neither metadata nor extents were lost during unmount.
> > +_scratch_cycle_mount
> > +
> > +# Check file data (and size).
> > +echo "File data:"
> > +_hexdump $SCRATCH_MNT/foo
> > +
> > +# Check we have unwritten extents in range [1M, 2M].
> > +echo "Fiemap output:"
> > +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap
> > +
> > +# Success, all done.
> > +_exit 0
> > diff --git a/tests/generic/796.out b/tests/generic/796.out
> > new file mode 100644
> > index 00000000..c6c6e6a8
> > --- /dev/null
> > +++ b/tests/generic/796.out
> > @@ -0,0 +1,10 @@
> > +QA output created by 796
> > +wrote 1048576/1048576 bytes at offset 0
> > +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> > +File data:
> > +000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab  >................<
> > +*
> > +100000
> > +Fiemap output:
> > +0: [0..2047]: data
> > +1: [2048..4095]: unwritten
> > --
> > 2.47.2
> >
> >