generic: fallocate two bytes at block boundary
diff mbox series

Message ID 20190926152927.2331-1-mreitz@redhat.com
State New
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Series
  • generic: fallocate two bytes at block boundary
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Commit Message

Max Reitz Sept. 26, 2019, 3:29 p.m. UTC
Allocating two bytes at a block boundary with fallocate should allocate
both blocks involved.  Test this by writing both bytes with dd
afterwards and see whether the on-disk size increases (it should not).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/generic/568     | 63 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/568.out |  2 ++
 tests/generic/group   |  1 +
 3 files changed, 66 insertions(+)
 create mode 100755 tests/generic/568
 create mode 100644 tests/generic/568.out

Comments

Darrick J. Wong Sept. 26, 2019, 3:55 p.m. UTC | #1
On Thu, Sep 26, 2019 at 05:29:27PM +0200, Max Reitz wrote:
> Allocating two bytes at a block boundary with fallocate should allocate
> both blocks involved.  Test this by writing both bytes with dd
> afterwards and see whether the on-disk size increases (it should not).
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  tests/generic/568     | 63 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/568.out |  2 ++
>  tests/generic/group   |  1 +
>  3 files changed, 66 insertions(+)
>  create mode 100755 tests/generic/568
>  create mode 100644 tests/generic/568.out
> 
> diff --git a/tests/generic/568 b/tests/generic/568
> new file mode 100755
> index 00000000..8fbdcda0
> --- /dev/null
> +++ b/tests/generic/568
> @@ -0,0 +1,63 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2019 Red Hat, Inc.  All Rights Reserved.
> +#
> +# FS QA Test No. generic/568
> +#
> +# Test that fallocating an unaligned range allocates all blocks
> +# touched by that range
> +#
> +seq=$(basename $0)
> +seqres="$RESULT_DIR/$seq"
> +echo "QA output created by $seq"
> +
> +here=$PWD
> +tmp=/tmp/$$
> +status=1	# failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -f "$tmp".*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +_require_scratch
> +
> +testfile="$SCRATCH_MNT/testfile"
> +
> +_scratch_mkfs > /dev/null 2>&1
> +_scratch_mount
> +
> +# Fallocate 2 bytes across a block boundary
> +block_size=$(stat -fc '%S' "$SCRATCH_MNT")

block_size=$(_get_file_block_size $SCRATCH_MNT)

> +fallocate -o $((block_size - 1)) -l 2 "$testfile"

If you're going to use an external program, you need to gate the test on
whether or not the program's installed, by calling _require_command.

Though probably the easier way would be to use xfs_io since fstests
requires that xfsprogs be installed:

	$XFS_IO_PROG -f -c "falloc $((block_size - 1)) 2" $testfile

Though you do still have to put at the top of the test:

	_require_xfs_io_command "falloc"

Because not all filesystems support fallocate.

> +
> +# Both the first blocks should be allocated now.  Check that by
> +# inquiring whether the file grows when we write to the two bytes we
> +# have just fallocated.
> +
> +allocated_size_before=$(($(stat -c '%b * %B' "$testfile")))
> +
> +dd if=/dev/zero of="$testfile" bs=1 conv=notrunc \
> +    seek=$((block_size - 1)) count=2 \
> +    2>&1 | _filter_dd

$XFS_IO_PROG -c "pwrite $((block_size - 1)) 2" $testfile

> +
> +allocated_size_after=$(($(stat -c '%b * %B' "$testfile")))
> +
> +if [ $allocated_size_after -gt $allocated_size_before ]; then
> +	echo "ERROR: File grew from ${allocated_size_before} B to" \
> +	     "${allocated_size_after} when writing to the fallocated range."
> +else
> +	echo "OK: File did not grow."

Other than that, the logic makes sense to me.  Thanks for writing this
up!

--D

> +fi
> +
> +status=0
> +exit
> diff --git a/tests/generic/568.out b/tests/generic/568.out
> new file mode 100644
> index 00000000..d8210882
> --- /dev/null
> +++ b/tests/generic/568.out
> @@ -0,0 +1,2 @@
> +QA output created by 568
> +OK: File did not grow.
> diff --git a/tests/generic/group b/tests/generic/group
> index 7cf4f6c4..24ab29bc 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -570,3 +570,4 @@
>  565 auto quick copy_range
>  566 auto quick quota metadata
>  567 auto quick rw punch
> +568 auto quick rw
> -- 
> 2.21.0
>
Max Reitz Sept. 26, 2019, 4:02 p.m. UTC | #2
On 26.09.19 17:55, Darrick J. Wong wrote:
> On Thu, Sep 26, 2019 at 05:29:27PM +0200, Max Reitz wrote:
>> Allocating two bytes at a block boundary with fallocate should allocate
>> both blocks involved.  Test this by writing both bytes with dd
>> afterwards and see whether the on-disk size increases (it should not).
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>  tests/generic/568     | 63 +++++++++++++++++++++++++++++++++++++++++++
>>  tests/generic/568.out |  2 ++
>>  tests/generic/group   |  1 +
>>  3 files changed, 66 insertions(+)
>>  create mode 100755 tests/generic/568
>>  create mode 100644 tests/generic/568.out
>>
>> diff --git a/tests/generic/568 b/tests/generic/568
>> new file mode 100755
>> index 00000000..8fbdcda0
>> --- /dev/null
>> +++ b/tests/generic/568
>> @@ -0,0 +1,63 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2019 Red Hat, Inc.  All Rights Reserved.
>> +#
>> +# FS QA Test No. generic/568
>> +#
>> +# Test that fallocating an unaligned range allocates all blocks
>> +# touched by that range
>> +#
>> +seq=$(basename $0)
>> +seqres="$RESULT_DIR/$seq"
>> +echo "QA output created by $seq"
>> +
>> +here=$PWD
>> +tmp=/tmp/$$
>> +status=1	# failure is the default!
>> +trap "_cleanup; exit \$status" 0 1 2 3 15
>> +
>> +_cleanup()
>> +{
>> +	cd /
>> +	rm -f "$tmp".*
>> +}
>> +
>> +# get standard environment, filters and checks
>> +. ./common/rc
>> +. ./common/filter
>> +
>> +# real QA test starts here
>> +_supported_fs generic
>> +_supported_os Linux
>> +_require_scratch
>> +
>> +testfile="$SCRATCH_MNT/testfile"
>> +
>> +_scratch_mkfs > /dev/null 2>&1
>> +_scratch_mount
>> +
>> +# Fallocate 2 bytes across a block boundary
>> +block_size=$(stat -fc '%S' "$SCRATCH_MNT")
> 
> block_size=$(_get_file_block_size $SCRATCH_MNT)

Ah, nice.

>> +fallocate -o $((block_size - 1)) -l 2 "$testfile"
> 
> If you're going to use an external program, you need to gate the test on
> whether or not the program's installed, by calling _require_command.

OK.

> Though probably the easier way would be to use xfs_io since fstests
> requires that xfsprogs be installed:
> 
> 	$XFS_IO_PROG -f -c "falloc $((block_size - 1)) 2" $testfile
> 
> Though you do still have to put at the top of the test:
> 
> 	_require_xfs_io_command "falloc"
> 
> Because not all filesystems support fallocate.

So I suppose as long as one doesn’t use special XFS commands, xfs_io is
filesystem-agnostic?

>> +
>> +# Both the first blocks should be allocated now.  Check that by
>> +# inquiring whether the file grows when we write to the two bytes we
>> +# have just fallocated.
>> +
>> +allocated_size_before=$(($(stat -c '%b * %B' "$testfile")))
>> +
>> +dd if=/dev/zero of="$testfile" bs=1 conv=notrunc \
>> +    seek=$((block_size - 1)) count=2 \
>> +    2>&1 | _filter_dd
> 
> $XFS_IO_PROG -c "pwrite $((block_size - 1)) 2" $testfile
> 
>> +
>> +allocated_size_after=$(($(stat -c '%b * %B' "$testfile")))
>> +
>> +if [ $allocated_size_after -gt $allocated_size_before ]; then
>> +	echo "ERROR: File grew from ${allocated_size_before} B to" \
>> +	     "${allocated_size_after} when writing to the fallocated range."
>> +else
>> +	echo "OK: File did not grow."
> 
> Other than that, the logic makes sense to me.  Thanks for writing this
> up!

OK, thanks, I’ll prepare a v2.

Max
Darrick J. Wong Sept. 26, 2019, 4:06 p.m. UTC | #3
On Thu, Sep 26, 2019 at 06:02:17PM +0200, Max Reitz wrote:
> On 26.09.19 17:55, Darrick J. Wong wrote:
> > On Thu, Sep 26, 2019 at 05:29:27PM +0200, Max Reitz wrote:
> >> Allocating two bytes at a block boundary with fallocate should allocate
> >> both blocks involved.  Test this by writing both bytes with dd
> >> afterwards and see whether the on-disk size increases (it should not).
> >>
> >> Signed-off-by: Max Reitz <mreitz@redhat.com>
> >> ---
> >>  tests/generic/568     | 63 +++++++++++++++++++++++++++++++++++++++++++
> >>  tests/generic/568.out |  2 ++
> >>  tests/generic/group   |  1 +
> >>  3 files changed, 66 insertions(+)
> >>  create mode 100755 tests/generic/568
> >>  create mode 100644 tests/generic/568.out
> >>
> >> diff --git a/tests/generic/568 b/tests/generic/568
> >> new file mode 100755
> >> index 00000000..8fbdcda0
> >> --- /dev/null
> >> +++ b/tests/generic/568
> >> @@ -0,0 +1,63 @@
> >> +#! /bin/bash
> >> +# SPDX-License-Identifier: GPL-2.0
> >> +# Copyright (c) 2019 Red Hat, Inc.  All Rights Reserved.
> >> +#
> >> +# FS QA Test No. generic/568
> >> +#
> >> +# Test that fallocating an unaligned range allocates all blocks
> >> +# touched by that range
> >> +#
> >> +seq=$(basename $0)
> >> +seqres="$RESULT_DIR/$seq"
> >> +echo "QA output created by $seq"
> >> +
> >> +here=$PWD
> >> +tmp=/tmp/$$
> >> +status=1	# failure is the default!
> >> +trap "_cleanup; exit \$status" 0 1 2 3 15
> >> +
> >> +_cleanup()
> >> +{
> >> +	cd /
> >> +	rm -f "$tmp".*
> >> +}
> >> +
> >> +# get standard environment, filters and checks
> >> +. ./common/rc
> >> +. ./common/filter
> >> +
> >> +# real QA test starts here
> >> +_supported_fs generic
> >> +_supported_os Linux
> >> +_require_scratch
> >> +
> >> +testfile="$SCRATCH_MNT/testfile"
> >> +
> >> +_scratch_mkfs > /dev/null 2>&1
> >> +_scratch_mount
> >> +
> >> +# Fallocate 2 bytes across a block boundary
> >> +block_size=$(stat -fc '%S' "$SCRATCH_MNT")
> > 
> > block_size=$(_get_file_block_size $SCRATCH_MNT)
> 
> Ah, nice.
> 
> >> +fallocate -o $((block_size - 1)) -l 2 "$testfile"
> > 
> > If you're going to use an external program, you need to gate the test on
> > whether or not the program's installed, by calling _require_command.
> 
> OK.
> 
> > Though probably the easier way would be to use xfs_io since fstests
> > requires that xfsprogs be installed:
> > 
> > 	$XFS_IO_PROG -f -c "falloc $((block_size - 1)) 2" $testfile
> > 
> > Though you do still have to put at the top of the test:
> > 
> > 	_require_xfs_io_command "falloc"
> > 
> > Because not all filesystems support fallocate.
> 
> So I suppose as long as one doesn’t use special XFS commands, xfs_io is
> filesystem-agnostic?

Right.  At this point xfs_io is largely a testing vehicle for fstests
scripts to call various system calls or ioctls, some of which aren't
even supported on XFS itself. :P

--D

> >> +
> >> +# Both the first blocks should be allocated now.  Check that by
> >> +# inquiring whether the file grows when we write to the two bytes we
> >> +# have just fallocated.
> >> +
> >> +allocated_size_before=$(($(stat -c '%b * %B' "$testfile")))
> >> +
> >> +dd if=/dev/zero of="$testfile" bs=1 conv=notrunc \
> >> +    seek=$((block_size - 1)) count=2 \
> >> +    2>&1 | _filter_dd
> > 
> > $XFS_IO_PROG -c "pwrite $((block_size - 1)) 2" $testfile
> > 
> >> +
> >> +allocated_size_after=$(($(stat -c '%b * %B' "$testfile")))
> >> +
> >> +if [ $allocated_size_after -gt $allocated_size_before ]; then
> >> +	echo "ERROR: File grew from ${allocated_size_before} B to" \
> >> +	     "${allocated_size_after} when writing to the fallocated range."
> >> +else
> >> +	echo "OK: File did not grow."
> > 
> > Other than that, the logic makes sense to me.  Thanks for writing this
> > up!
> 
> OK, thanks, I’ll prepare a v2.
> 
> Max
>

Patch
diff mbox series

diff --git a/tests/generic/568 b/tests/generic/568
new file mode 100755
index 00000000..8fbdcda0
--- /dev/null
+++ b/tests/generic/568
@@ -0,0 +1,63 @@ 
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2019 Red Hat, Inc.  All Rights Reserved.
+#
+# FS QA Test No. generic/568
+#
+# Test that fallocating an unaligned range allocates all blocks
+# touched by that range
+#
+seq=$(basename $0)
+seqres="$RESULT_DIR/$seq"
+echo "QA output created by $seq"
+
+here=$PWD
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f "$tmp".*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_scratch
+
+testfile="$SCRATCH_MNT/testfile"
+
+_scratch_mkfs > /dev/null 2>&1
+_scratch_mount
+
+# Fallocate 2 bytes across a block boundary
+block_size=$(stat -fc '%S' "$SCRATCH_MNT")
+fallocate -o $((block_size - 1)) -l 2 "$testfile"
+
+# Both the first blocks should be allocated now.  Check that by
+# inquiring whether the file grows when we write to the two bytes we
+# have just fallocated.
+
+allocated_size_before=$(($(stat -c '%b * %B' "$testfile")))
+
+dd if=/dev/zero of="$testfile" bs=1 conv=notrunc \
+    seek=$((block_size - 1)) count=2 \
+    2>&1 | _filter_dd
+
+allocated_size_after=$(($(stat -c '%b * %B' "$testfile")))
+
+if [ $allocated_size_after -gt $allocated_size_before ]; then
+	echo "ERROR: File grew from ${allocated_size_before} B to" \
+	     "${allocated_size_after} when writing to the fallocated range."
+else
+	echo "OK: File did not grow."
+fi
+
+status=0
+exit
diff --git a/tests/generic/568.out b/tests/generic/568.out
new file mode 100644
index 00000000..d8210882
--- /dev/null
+++ b/tests/generic/568.out
@@ -0,0 +1,2 @@ 
+QA output created by 568
+OK: File did not grow.
diff --git a/tests/generic/group b/tests/generic/group
index 7cf4f6c4..24ab29bc 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -570,3 +570,4 @@ 
 565 auto quick copy_range
 566 auto quick quota metadata
 567 auto quick rw punch
+568 auto quick rw