[PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

This is a regression test for a Btrfs bug, but there's nothing
Btrfs-specific about it. Since it's a race, we just try to make the race
happen in a loop and pass if it doesn't crash after all of our attempts.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
Changes from v1 [1]:

- Added missing groups and requires.
- Simplified $XFS_IO_PROG calls.
- Removed -i flag from $XFS_IO_PROG to make race reproduce more
  reliably.
- Removed all of the file creation and dump-tree parsing since the only
  file on a fresh filesystem is guaranteed to be at the end of a leaf
  anyways.
- Rewrote to be a generic test.

1: https://lore.kernel.org/linux-btrfs/297da2b53ce9b697d82d89afd322b2cc0d0f392d.1716492850.git.osandov@osandov.com/

 tests/generic/745     | 44 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/745.out |  2 ++
 2 files changed, 46 insertions(+)
 create mode 100755 tests/generic/745
 create mode 100644 tests/generic/745.out

diff --git a/tests/generic/745 b/tests/generic/745
new file mode 100755
index 00000000..925adba9
--- /dev/null
+++ b/tests/generic/745
@@ -0,0 +1,44 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# FS QA Test 745
+#
+# Repeatedly prealloc beyond i_size, set an xattr, direct write into the
+# prealloc while extending i_size, then fdatasync. This is a regression test
+# for a Btrfs crash.
+#
+. ./common/preamble
+. ./common/attr
+_begin_fstest auto quick log preallocrw dangerous
+
+_supported_fs generic
+_require_scratch
+_require_attrs
+_require_xfs_io_command falloc -k
+_fixed_by_kernel_commit XXXXXXXXXXXX \
+	"btrfs: fix crash on racing fsync and size-extending write into prealloc"
+
+# -i slows down xfs_io startup and makes the race much less reliable.
+export XFS_IO_PROG="$(echo "$XFS_IO_PROG" | sed 's/ -i\b//')"
+
+_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
+_scratch_mount
+
+blksz=$(_get_block_size "$SCRATCH_MNT")
+
+# On Btrfs, since this is the only file on the filesystem, its metadata is at
+# the end of a B-tree leaf. We want an ordered extent completion to add an
+# extent item at the end of the leaf while we're logging prealloc extents
+# beyond i_size after an xattr was set.
+for ((i = 0; i < 5000; i++)); do
+	$XFS_IO_PROG -ftd -c "falloc -k 0 $((blksz * 3))" -c "pwrite -q -w 0 $blksz" "$SCRATCH_MNT/file"
+	$SETFATTR_PROG -n user.a -v a "$SCRATCH_MNT/file"
+	$XFS_IO_PROG -d -c "pwrite -q -w $blksz $blksz" "$SCRATCH_MNT/file"
+done
+
+# If it didn't crash, we're good.
+
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/generic/745.out b/tests/generic/745.out
new file mode 100644
index 00000000..fce6b7f5
--- /dev/null
+++ b/tests/generic/745.out
@@ -0,0 +1,2 @@
+QA output created by 745
+Silence is golden
-- 
2.45.1

Re: [PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[Filipe Manana]

On Fri, May 24, 2024 at 9:58 PM Omar Sandoval <osandov@osandov.com> wrote:
>
> From: Omar Sandoval <osandov@fb.com>
>
> This is a regression test for a Btrfs bug, but there's nothing
> Btrfs-specific about it. Since it's a race, we just try to make the race
> happen in a loop and pass if it doesn't crash after all of our attempts.
>
> Signed-off-by: Omar Sandoval <osandov@fb.com>
> ---
> Changes from v1 [1]:
>
> - Added missing groups and requires.
> - Simplified $XFS_IO_PROG calls.
> - Removed -i flag from $XFS_IO_PROG to make race reproduce more
>   reliably.
> - Removed all of the file creation and dump-tree parsing since the only
>   file on a fresh filesystem is guaranteed to be at the end of a leaf
>   anyways.
> - Rewrote to be a generic test.
>
> 1: https://lore.kernel.org/linux-btrfs/297da2b53ce9b697d82d89afd322b2cc0d0f392d.1716492850.git.osandov@osandov.com/
>
>  tests/generic/745     | 44 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/745.out |  2 ++
>  2 files changed, 46 insertions(+)
>  create mode 100755 tests/generic/745
>  create mode 100644 tests/generic/745.out
>
> diff --git a/tests/generic/745 b/tests/generic/745
> new file mode 100755
> index 00000000..925adba9
> --- /dev/null
> +++ b/tests/generic/745

Btw, generic/745 already exists in the for-next branch (development is
based against that branch nowadays).

> @@ -0,0 +1,44 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) Meta Platforms, Inc. and affiliates.
> +#
> +# FS QA Test 745
> +#
> +# Repeatedly prealloc beyond i_size, set an xattr, direct write into the
> +# prealloc while extending i_size, then fdatasync. This is a regression test
> +# for a Btrfs crash.
> +#
> +. ./common/preamble
> +. ./common/attr
> +_begin_fstest auto quick log preallocrw dangerous
> +
> +_supported_fs generic
> +_require_scratch
> +_require_attrs
> +_require_xfs_io_command falloc -k

Since this is now a generic test and we're using direct IO, also:

_require_odirect

> +_fixed_by_kernel_commit XXXXXXXXXXXX \
> +       "btrfs: fix crash on racing fsync and size-extending write into prealloc"

Because it's now a generic test, it should be:

[ "$FSTYP" = "btrfs" ] && _fixed_by_kernel_commit ....

Otherwise it looks good to me, so with that:

Reviewed-by: Filipe Manana <fdmanana@suse.com>

Thanks.

> +
> +# -i slows down xfs_io startup and makes the race much less reliable.
> +export XFS_IO_PROG="$(echo "$XFS_IO_PROG" | sed 's/ -i\b//')"
> +
> +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> +_scratch_mount
> +
> +blksz=$(_get_block_size "$SCRATCH_MNT")
> +
> +# On Btrfs, since this is the only file on the filesystem, its metadata is at
> +# the end of a B-tree leaf. We want an ordered extent completion to add an
> +# extent item at the end of the leaf while we're logging prealloc extents
> +# beyond i_size after an xattr was set.
> +for ((i = 0; i < 5000; i++)); do
> +       $XFS_IO_PROG -ftd -c "falloc -k 0 $((blksz * 3))" -c "pwrite -q -w 0 $blksz" "$SCRATCH_MNT/file"
> +       $SETFATTR_PROG -n user.a -v a "$SCRATCH_MNT/file"
> +       $XFS_IO_PROG -d -c "pwrite -q -w $blksz $blksz" "$SCRATCH_MNT/file"
> +done
> +
> +# If it didn't crash, we're good.
> +
> +echo "Silence is golden"
> +status=0
> +exit
> diff --git a/tests/generic/745.out b/tests/generic/745.out
> new file mode 100644
> index 00000000..fce6b7f5
> --- /dev/null
> +++ b/tests/generic/745.out
> @@ -0,0 +1,2 @@
> +QA output created by 745
> +Silence is golden
> --
> 2.45.1
>
>

Re: [PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[Zorro Lang]

On Sun, May 26, 2024 at 12:47:49PM +0100, Filipe Manana wrote:
> On Fri, May 24, 2024 at 9:58 PM Omar Sandoval <osandov@osandov.com> wrote:
> >
> > From: Omar Sandoval <osandov@fb.com>
> >
> > This is a regression test for a Btrfs bug, but there's nothing
> > Btrfs-specific about it. Since it's a race, we just try to make the race
> > happen in a loop and pass if it doesn't crash after all of our attempts.
> >
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > ---
> > Changes from v1 [1]:
> >
> > - Added missing groups and requires.
> > - Simplified $XFS_IO_PROG calls.
> > - Removed -i flag from $XFS_IO_PROG to make race reproduce more
> >   reliably.
> > - Removed all of the file creation and dump-tree parsing since the only
> >   file on a fresh filesystem is guaranteed to be at the end of a leaf
> >   anyways.
> > - Rewrote to be a generic test.
> >
> > 1: https://lore.kernel.org/linux-btrfs/297da2b53ce9b697d82d89afd322b2cc0d0f392d.1716492850.git.osandov@osandov.com/
> >
> >  tests/generic/745     | 44 +++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/745.out |  2 ++
> >  2 files changed, 46 insertions(+)
> >  create mode 100755 tests/generic/745
> >  create mode 100644 tests/generic/745.out
> >
> > diff --git a/tests/generic/745 b/tests/generic/745
> > new file mode 100755
> > index 00000000..925adba9
> > --- /dev/null
> > +++ b/tests/generic/745
> 
> Btw, generic/745 already exists in the for-next branch (development is
> based against that branch nowadays).
> 
> > @@ -0,0 +1,44 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) Meta Platforms, Inc. and affiliates.
> > +#
> > +# FS QA Test 745
> > +#
> > +# Repeatedly prealloc beyond i_size, set an xattr, direct write into the
> > +# prealloc while extending i_size, then fdatasync. This is a regression test
> > +# for a Btrfs crash.
> > +#
> > +. ./common/preamble
> > +. ./common/attr
> > +_begin_fstest auto quick log preallocrw dangerous
> > +
> > +_supported_fs generic
> > +_require_scratch
> > +_require_attrs
> > +_require_xfs_io_command falloc -k
> 
> Since this is now a generic test and we're using direct IO, also:
> 
> _require_odirect
> 
> > +_fixed_by_kernel_commit XXXXXXXXXXXX \
> > +       "btrfs: fix crash on racing fsync and size-extending write into prealloc"
> 
> Because it's now a generic test, it should be:
> 
> [ "$FSTYP" = "btrfs" ] && _fixed_by_kernel_commit ....
> 
> Otherwise it looks good to me, so with that:
> 
> Reviewed-by: Filipe Manana <fdmanana@suse.com>

Thanks Filipe, merged this patch with above review points, more details refer to
"patches-in-queue" branch. Feel free to have more review points before I push
to for-next :)

Thanks,
Zorro

> 
> Thanks.
> 
> > +
> > +# -i slows down xfs_io startup and makes the race much less reliable.
> > +export XFS_IO_PROG="$(echo "$XFS_IO_PROG" | sed 's/ -i\b//')"
> > +
> > +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> > +_scratch_mount
> > +
> > +blksz=$(_get_block_size "$SCRATCH_MNT")
> > +
> > +# On Btrfs, since this is the only file on the filesystem, its metadata is at
> > +# the end of a B-tree leaf. We want an ordered extent completion to add an
> > +# extent item at the end of the leaf while we're logging prealloc extents
> > +# beyond i_size after an xattr was set.
> > +for ((i = 0; i < 5000; i++)); do
> > +       $XFS_IO_PROG -ftd -c "falloc -k 0 $((blksz * 3))" -c "pwrite -q -w 0 $blksz" "$SCRATCH_MNT/file"
> > +       $SETFATTR_PROG -n user.a -v a "$SCRATCH_MNT/file"
> > +       $XFS_IO_PROG -d -c "pwrite -q -w $blksz $blksz" "$SCRATCH_MNT/file"
> > +done
> > +
> > +# If it didn't crash, we're good.
> > +
> > +echo "Silence is golden"
> > +status=0
> > +exit
> > diff --git a/tests/generic/745.out b/tests/generic/745.out
> > new file mode 100644
> > index 00000000..fce6b7f5
> > --- /dev/null
> > +++ b/tests/generic/745.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 745
> > +Silence is golden
> > --
> > 2.45.1
> >
> >
> 

Re: [PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[Filipe Manana]

On Fri, Jun 7, 2024 at 6:12 AM Zorro Lang <zlang@redhat.com> wrote:
>
> On Sun, May 26, 2024 at 12:47:49PM +0100, Filipe Manana wrote:
> > On Fri, May 24, 2024 at 9:58 PM Omar Sandoval <osandov@osandov.com> wrote:
> > >
> > > From: Omar Sandoval <osandov@fb.com>
> > >
> > > This is a regression test for a Btrfs bug, but there's nothing
> > > Btrfs-specific about it. Since it's a race, we just try to make the race
> > > happen in a loop and pass if it doesn't crash after all of our attempts.
> > >
> > > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > > ---
> > > Changes from v1 [1]:
> > >
> > > - Added missing groups and requires.
> > > - Simplified $XFS_IO_PROG calls.
> > > - Removed -i flag from $XFS_IO_PROG to make race reproduce more
> > >   reliably.
> > > - Removed all of the file creation and dump-tree parsing since the only
> > >   file on a fresh filesystem is guaranteed to be at the end of a leaf
> > >   anyways.
> > > - Rewrote to be a generic test.
> > >
> > > 1: https://lore.kernel.org/linux-btrfs/297da2b53ce9b697d82d89afd322b2cc0d0f392d.1716492850.git.osandov@osandov.com/
> > >
> > >  tests/generic/745     | 44 +++++++++++++++++++++++++++++++++++++++++++
> > >  tests/generic/745.out |  2 ++
> > >  2 files changed, 46 insertions(+)
> > >  create mode 100755 tests/generic/745
> > >  create mode 100644 tests/generic/745.out
> > >
> > > diff --git a/tests/generic/745 b/tests/generic/745
> > > new file mode 100755
> > > index 00000000..925adba9
> > > --- /dev/null
> > > +++ b/tests/generic/745
> >
> > Btw, generic/745 already exists in the for-next branch (development is
> > based against that branch nowadays).
> >
> > > @@ -0,0 +1,44 @@
> > > +#! /bin/bash
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +# Copyright (c) Meta Platforms, Inc. and affiliates.
> > > +#
> > > +# FS QA Test 745
> > > +#
> > > +# Repeatedly prealloc beyond i_size, set an xattr, direct write into the
> > > +# prealloc while extending i_size, then fdatasync. This is a regression test
> > > +# for a Btrfs crash.
> > > +#
> > > +. ./common/preamble
> > > +. ./common/attr
> > > +_begin_fstest auto quick log preallocrw dangerous
> > > +
> > > +_supported_fs generic
> > > +_require_scratch
> > > +_require_attrs
> > > +_require_xfs_io_command falloc -k
> >
> > Since this is now a generic test and we're using direct IO, also:
> >
> > _require_odirect
> >
> > > +_fixed_by_kernel_commit XXXXXXXXXXXX \
> > > +       "btrfs: fix crash on racing fsync and size-extending write into prealloc"
> >
> > Because it's now a generic test, it should be:
> >
> > [ "$FSTYP" = "btrfs" ] && _fixed_by_kernel_commit ....
> >
> > Otherwise it looks good to me, so with that:
> >
> > Reviewed-by: Filipe Manana <fdmanana@suse.com>
>
> Thanks Filipe, merged this patch with above review points, more details refer to
> "patches-in-queue" branch. Feel free to have more review points before I push
> to for-next :)

Btw, there's a v3 with all that addressed:

https://lore.kernel.org/fstests/8c91247dd109bb94e8df36f2812274b5de2a7183.1716916346.git.osandov@osandov.com/

Also, looking at patches-in-queue, the test was added twice, once as
generic/748 and once as generic/749, in two different commits.

Also, unrelated, but this commit:

https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/commit/?h=patches-in-queue&id=b4c4ba99435aa7fd4f8a6e3c02938e357e137ec9

As a Signed-off-by tag for David Disseldorp instead of Reviewed-by.

Thanks.

>
> Thanks,
> Zorro
>
> >
> > Thanks.
> >
> > > +
> > > +# -i slows down xfs_io startup and makes the race much less reliable.
> > > +export XFS_IO_PROG="$(echo "$XFS_IO_PROG" | sed 's/ -i\b//')"
> > > +
> > > +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> > > +_scratch_mount
> > > +
> > > +blksz=$(_get_block_size "$SCRATCH_MNT")
> > > +
> > > +# On Btrfs, since this is the only file on the filesystem, its metadata is at
> > > +# the end of a B-tree leaf. We want an ordered extent completion to add an
> > > +# extent item at the end of the leaf while we're logging prealloc extents
> > > +# beyond i_size after an xattr was set.
> > > +for ((i = 0; i < 5000; i++)); do
> > > +       $XFS_IO_PROG -ftd -c "falloc -k 0 $((blksz * 3))" -c "pwrite -q -w 0 $blksz" "$SCRATCH_MNT/file"
> > > +       $SETFATTR_PROG -n user.a -v a "$SCRATCH_MNT/file"
> > > +       $XFS_IO_PROG -d -c "pwrite -q -w $blksz $blksz" "$SCRATCH_MNT/file"
> > > +done
> > > +
> > > +# If it didn't crash, we're good.
> > > +
> > > +echo "Silence is golden"
> > > +status=0
> > > +exit
> > > diff --git a/tests/generic/745.out b/tests/generic/745.out
> > > new file mode 100644
> > > index 00000000..fce6b7f5
> > > --- /dev/null
> > > +++ b/tests/generic/745.out
> > > @@ -0,0 +1,2 @@
> > > +QA output created by 745
> > > +Silence is golden
> > > --
> > > 2.45.1
> > >
> > >
> >
>

Re: [PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[Zorro Lang]

On Fri, Jun 07, 2024 at 10:43:47AM +0100, Filipe Manana wrote:
> On Fri, Jun 7, 2024 at 6:12 AM Zorro Lang <zlang@redhat.com> wrote:
> >
> > On Sun, May 26, 2024 at 12:47:49PM +0100, Filipe Manana wrote:
> > > On Fri, May 24, 2024 at 9:58 PM Omar Sandoval <osandov@osandov.com> wrote:
> > > >
> > > > From: Omar Sandoval <osandov@fb.com>
> > > >
> > > > This is a regression test for a Btrfs bug, but there's nothing
> > > > Btrfs-specific about it. Since it's a race, we just try to make the race
> > > > happen in a loop and pass if it doesn't crash after all of our attempts.
> > > >
> > > > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > > > ---
> > > > Changes from v1 [1]:
> > > >
> > > > - Added missing groups and requires.
> > > > - Simplified $XFS_IO_PROG calls.
> > > > - Removed -i flag from $XFS_IO_PROG to make race reproduce more
> > > >   reliably.
> > > > - Removed all of the file creation and dump-tree parsing since the only
> > > >   file on a fresh filesystem is guaranteed to be at the end of a leaf
> > > >   anyways.
> > > > - Rewrote to be a generic test.
> > > >
> > > > 1: https://lore.kernel.org/linux-btrfs/297da2b53ce9b697d82d89afd322b2cc0d0f392d.1716492850.git.osandov@osandov.com/
> > > >
> > > >  tests/generic/745     | 44 +++++++++++++++++++++++++++++++++++++++++++
> > > >  tests/generic/745.out |  2 ++
> > > >  2 files changed, 46 insertions(+)
> > > >  create mode 100755 tests/generic/745
> > > >  create mode 100644 tests/generic/745.out
> > > >
> > > > diff --git a/tests/generic/745 b/tests/generic/745
> > > > new file mode 100755
> > > > index 00000000..925adba9
> > > > --- /dev/null
> > > > +++ b/tests/generic/745
> > >
> > > Btw, generic/745 already exists in the for-next branch (development is
> > > based against that branch nowadays).
> > >
> > > > @@ -0,0 +1,44 @@
> > > > +#! /bin/bash
> > > > +# SPDX-License-Identifier: GPL-2.0
> > > > +# Copyright (c) Meta Platforms, Inc. and affiliates.
> > > > +#
> > > > +# FS QA Test 745
> > > > +#
> > > > +# Repeatedly prealloc beyond i_size, set an xattr, direct write into the
> > > > +# prealloc while extending i_size, then fdatasync. This is a regression test
> > > > +# for a Btrfs crash.
> > > > +#
> > > > +. ./common/preamble
> > > > +. ./common/attr
> > > > +_begin_fstest auto quick log preallocrw dangerous
> > > > +
> > > > +_supported_fs generic
> > > > +_require_scratch
> > > > +_require_attrs
> > > > +_require_xfs_io_command falloc -k
> > >
> > > Since this is now a generic test and we're using direct IO, also:
> > >
> > > _require_odirect
> > >
> > > > +_fixed_by_kernel_commit XXXXXXXXXXXX \
> > > > +       "btrfs: fix crash on racing fsync and size-extending write into prealloc"
> > >
> > > Because it's now a generic test, it should be:
> > >
> > > [ "$FSTYP" = "btrfs" ] && _fixed_by_kernel_commit ....
> > >
> > > Otherwise it looks good to me, so with that:
> > >
> > > Reviewed-by: Filipe Manana <fdmanana@suse.com>
> >
> > Thanks Filipe, merged this patch with above review points, more details refer to
> > "patches-in-queue" branch. Feel free to have more review points before I push
> > to for-next :)
> 
> Btw, there's a v3 with all that addressed:
> 
> https://lore.kernel.org/fstests/8c91247dd109bb94e8df36f2812274b5de2a7183.1716916346.git.osandov@osandov.com/
> 
> Also, looking at patches-in-queue, the test was added twice, once as
> generic/748 and once as generic/749, in two different commits.

Oh, I've merged this test case last week... sorry I forgot that. I'll keep
the g/748, and remove the g/749.

> 
> Also, unrelated, but this commit:
> 
> https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/commit/?h=patches-in-queue&id=b4c4ba99435aa7fd4f8a6e3c02938e357e137ec9
> 
> As a Signed-off-by tag for David Disseldorp instead of Reviewed-by.

Oh, this Signed-off-by tag is generated automatically by:

https://lore.kernel.org/fstests/c9e54af5-4370-4d45-a8ed-4098b06b2629@suse.com/T/#m8fc24d233b2cf3a323c94c2b8039c0f043e09023

if it's a mistake, I'll change it to Reviewed-by:

Thanks,
Zorro

> 
> Thanks.
> 
> >
> > Thanks,
> > Zorro
> >
> > >
> > > Thanks.
> > >
> > > > +
> > > > +# -i slows down xfs_io startup and makes the race much less reliable.
> > > > +export XFS_IO_PROG="$(echo "$XFS_IO_PROG" | sed 's/ -i\b//')"
> > > > +
> > > > +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> > > > +_scratch_mount
> > > > +
> > > > +blksz=$(_get_block_size "$SCRATCH_MNT")
> > > > +
> > > > +# On Btrfs, since this is the only file on the filesystem, its metadata is at
> > > > +# the end of a B-tree leaf. We want an ordered extent completion to add an
> > > > +# extent item at the end of the leaf while we're logging prealloc extents
> > > > +# beyond i_size after an xattr was set.
> > > > +for ((i = 0; i < 5000; i++)); do
> > > > +       $XFS_IO_PROG -ftd -c "falloc -k 0 $((blksz * 3))" -c "pwrite -q -w 0 $blksz" "$SCRATCH_MNT/file"
> > > > +       $SETFATTR_PROG -n user.a -v a "$SCRATCH_MNT/file"
> > > > +       $XFS_IO_PROG -d -c "pwrite -q -w $blksz $blksz" "$SCRATCH_MNT/file"
> > > > +done
> > > > +
> > > > +# If it didn't crash, we're good.
> > > > +
> > > > +echo "Silence is golden"
> > > > +status=0
> > > > +exit
> > > > diff --git a/tests/generic/745.out b/tests/generic/745.out
> > > > new file mode 100644
> > > > index 00000000..fce6b7f5
> > > > --- /dev/null
> > > > +++ b/tests/generic/745.out
> > > > @@ -0,0 +1,2 @@
> > > > +QA output created by 745
> > > > +Silence is golden
> > > > --
> > > > 2.45.1
> > > >
> > > >
> > >
> >
> 

Re: [PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[Filipe Manana]

On Fri, Jun 7, 2024 at 11:04 AM Zorro Lang <zlang@redhat.com> wrote:
>
> On Fri, Jun 07, 2024 at 10:43:47AM +0100, Filipe Manana wrote:
> > On Fri, Jun 7, 2024 at 6:12 AM Zorro Lang <zlang@redhat.com> wrote:
> > >
> > > On Sun, May 26, 2024 at 12:47:49PM +0100, Filipe Manana wrote:
> > > > On Fri, May 24, 2024 at 9:58 PM Omar Sandoval <osandov@osandov.com> wrote:
> > > > >
> > > > > From: Omar Sandoval <osandov@fb.com>
> > > > >
> > > > > This is a regression test for a Btrfs bug, but there's nothing
> > > > > Btrfs-specific about it. Since it's a race, we just try to make the race
> > > > > happen in a loop and pass if it doesn't crash after all of our attempts.
> > > > >
> > > > > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > > > > ---
> > > > > Changes from v1 [1]:
> > > > >
> > > > > - Added missing groups and requires.
> > > > > - Simplified $XFS_IO_PROG calls.
> > > > > - Removed -i flag from $XFS_IO_PROG to make race reproduce more
> > > > >   reliably.
> > > > > - Removed all of the file creation and dump-tree parsing since the only
> > > > >   file on a fresh filesystem is guaranteed to be at the end of a leaf
> > > > >   anyways.
> > > > > - Rewrote to be a generic test.
> > > > >
> > > > > 1: https://lore.kernel.org/linux-btrfs/297da2b53ce9b697d82d89afd322b2cc0d0f392d.1716492850.git.osandov@osandov.com/
> > > > >
> > > > >  tests/generic/745     | 44 +++++++++++++++++++++++++++++++++++++++++++
> > > > >  tests/generic/745.out |  2 ++
> > > > >  2 files changed, 46 insertions(+)
> > > > >  create mode 100755 tests/generic/745
> > > > >  create mode 100644 tests/generic/745.out
> > > > >
> > > > > diff --git a/tests/generic/745 b/tests/generic/745
> > > > > new file mode 100755
> > > > > index 00000000..925adba9
> > > > > --- /dev/null
> > > > > +++ b/tests/generic/745
> > > >
> > > > Btw, generic/745 already exists in the for-next branch (development is
> > > > based against that branch nowadays).
> > > >
> > > > > @@ -0,0 +1,44 @@
> > > > > +#! /bin/bash
> > > > > +# SPDX-License-Identifier: GPL-2.0
> > > > > +# Copyright (c) Meta Platforms, Inc. and affiliates.
> > > > > +#
> > > > > +# FS QA Test 745
> > > > > +#
> > > > > +# Repeatedly prealloc beyond i_size, set an xattr, direct write into the
> > > > > +# prealloc while extending i_size, then fdatasync. This is a regression test
> > > > > +# for a Btrfs crash.
> > > > > +#
> > > > > +. ./common/preamble
> > > > > +. ./common/attr
> > > > > +_begin_fstest auto quick log preallocrw dangerous
> > > > > +
> > > > > +_supported_fs generic
> > > > > +_require_scratch
> > > > > +_require_attrs
> > > > > +_require_xfs_io_command falloc -k
> > > >
> > > > Since this is now a generic test and we're using direct IO, also:
> > > >
> > > > _require_odirect
> > > >
> > > > > +_fixed_by_kernel_commit XXXXXXXXXXXX \
> > > > > +       "btrfs: fix crash on racing fsync and size-extending write into prealloc"
> > > >
> > > > Because it's now a generic test, it should be:
> > > >
> > > > [ "$FSTYP" = "btrfs" ] && _fixed_by_kernel_commit ....
> > > >
> > > > Otherwise it looks good to me, so with that:
> > > >
> > > > Reviewed-by: Filipe Manana <fdmanana@suse.com>
> > >
> > > Thanks Filipe, merged this patch with above review points, more details refer to
> > > "patches-in-queue" branch. Feel free to have more review points before I push
> > > to for-next :)
> >
> > Btw, there's a v3 with all that addressed:
> >
> > https://lore.kernel.org/fstests/8c91247dd109bb94e8df36f2812274b5de2a7183.1716916346.git.osandov@osandov.com/
> >
> > Also, looking at patches-in-queue, the test was added twice, once as
> > generic/748 and once as generic/749, in two different commits.
>
> Oh, I've merged this test case last week... sorry I forgot that. I'll keep
> the g/748, and remove the g/749.
>
> >
> > Also, unrelated, but this commit:
> >
> > https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/commit/?h=patches-in-queue&id=b4c4ba99435aa7fd4f8a6e3c02938e357e137ec9
> >
> > As a Signed-off-by tag for David Disseldorp instead of Reviewed-by.
>
> Oh, this Signed-off-by tag is generated automatically by:
>
> https://lore.kernel.org/fstests/c9e54af5-4370-4d45-a8ed-4098b06b2629@suse.com/T/#m8fc24d233b2cf3a323c94c2b8039c0f043e09023
>
> if it's a mistake, I'll change it to Reviewed-by:

That I didn't notice, odd that David replied with Signed-off-by and
not Reviewed-by.
(cc'ing him)

Thanks.

>
> Thanks,
> Zorro
>
> >
> > Thanks.
> >
> > >
> > > Thanks,
> > > Zorro
> > >
> > > >
> > > > Thanks.
> > > >
> > > > > +
> > > > > +# -i slows down xfs_io startup and makes the race much less reliable.
> > > > > +export XFS_IO_PROG="$(echo "$XFS_IO_PROG" | sed 's/ -i\b//')"
> > > > > +
> > > > > +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> > > > > +_scratch_mount
> > > > > +
> > > > > +blksz=$(_get_block_size "$SCRATCH_MNT")
> > > > > +
> > > > > +# On Btrfs, since this is the only file on the filesystem, its metadata is at
> > > > > +# the end of a B-tree leaf. We want an ordered extent completion to add an
> > > > > +# extent item at the end of the leaf while we're logging prealloc extents
> > > > > +# beyond i_size after an xattr was set.
> > > > > +for ((i = 0; i < 5000; i++)); do
> > > > > +       $XFS_IO_PROG -ftd -c "falloc -k 0 $((blksz * 3))" -c "pwrite -q -w 0 $blksz" "$SCRATCH_MNT/file"
> > > > > +       $SETFATTR_PROG -n user.a -v a "$SCRATCH_MNT/file"
> > > > > +       $XFS_IO_PROG -d -c "pwrite -q -w $blksz $blksz" "$SCRATCH_MNT/file"
> > > > > +done
> > > > > +
> > > > > +# If it didn't crash, we're good.
> > > > > +
> > > > > +echo "Silence is golden"
> > > > > +status=0
> > > > > +exit
> > > > > diff --git a/tests/generic/745.out b/tests/generic/745.out
> > > > > new file mode 100644
> > > > > index 00000000..fce6b7f5
> > > > > --- /dev/null
> > > > > +++ b/tests/generic/745.out
> > > > > @@ -0,0 +1,2 @@
> > > > > +QA output created by 745
> > > > > +Silence is golden
> > > > > --
> > > > > 2.45.1
> > > > >
> > > > >
> > > >
> > >
> >
>

Re: [PATCH fstests v2] generic: test Btrfs fsync vs. size-extending prealloc write crash

[David Disseldorp]

On Fri, 7 Jun 2024 11:11:34 +0100, Filipe Manana wrote:
...
> > > As a Signed-off-by tag for David Disseldorp instead of Reviewed-by.  
> >
> > Oh, this Signed-off-by tag is generated automatically by:
> >
> > https://lore.kernel.org/fstests/c9e54af5-4370-4d45-a8ed-4098b06b2629@suse.com/T/#m8fc24d233b2cf3a323c94c2b8039c0f043e09023
> >
> > if it's a mistake, I'll change it to Reviewed-by:  
> 
> That I didn't notice, odd that David replied with Signed-off-by and
> not Reviewed-by.
> (cc'ing him)

Oops, yes that should have been a Reviewed-by, sorry.
Please change it.

Thanks, David