[PATCH] btrfs: test ENOSPC caused by many orphan items

[PATCH] btrfs: test ENOSPC caused by many orphan items

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

Btrfs has a bug where we can prematurely ENOSPC if we have lots of
orphaned files, i.e., deleted files which are still open. Add a test
which repeatedly creates and deletes a file while keeping all of the
file descriptors open. This should succeed but doesn't on Btrfs without
the fix.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 tests/generic/479     |  0
 tests/generic/487     | 65 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/487.out |  2 ++
 tests/generic/group   |  1 +
 4 files changed, 68 insertions(+)
 mode change 100644 => 100755 tests/generic/479
 create mode 100755 tests/generic/487
 create mode 100644 tests/generic/487.out

diff --git a/tests/generic/479 b/tests/generic/479
old mode 100644
new mode 100755
diff --git a/tests/generic/487 b/tests/generic/487
new file mode 100755
index 00000000..66379cf0
--- /dev/null
+++ b/tests/generic/487
@@ -0,0 +1,65 @@
+#! /bin/bash
+# FS QA Test 487
+#
+# Test having many file descriptors referring to deleted files open. Regression
+# test for patch "Btrfs: fix ENOSPC caused by orphan items reservations".
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2018 Omar Sandoval.  All Rights Reserved.
+#
+# 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.
+#
+# This program is distributed in the hope that it would 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, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+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.*
+}
+
+. ./common/rc
+. ./common/filter
+
+rm -f $seqres.full
+
+_supported_fs generic
+_supported_os Linux
+_require_scratch
+
+_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full 2>&1
+_scratch_mount
+
+test_file="$SCRATCH_MNT/$seq"
+
+(
+ulimit -n $((16 * 1024))
+# ~10000 files on a 1 GB filesystem should be no problem.
+for ((i = 1000; i < 10000; i++)); do
+	eval "exec $i<> \"$test_file\"" && rm "$test_file" || break
+done
+)
+
+echo "Silence is golden"
+
+status=0
+exit
diff --git a/tests/generic/487.out b/tests/generic/487.out
new file mode 100644
index 00000000..5f31fd97
--- /dev/null
+++ b/tests/generic/487.out
@@ -0,0 +1,2 @@
+QA output created by 487
+Silence is golden
diff --git a/tests/generic/group b/tests/generic/group
index 505383f7..93581257 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -489,3 +489,4 @@
 484 auto quick
 485 auto quick insert
 486 auto quick attr
+487 auto quick
-- 
2.17.0

Re: [PATCH] btrfs: test ENOSPC caused by many orphan items

[Eryu Guan]

On Wed, May 09, 2018 at 11:21:55PM -0700, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Btrfs has a bug where we can prematurely ENOSPC if we have lots of
> orphaned files, i.e., deleted files which are still open. Add a test
> which repeatedly creates and deletes a file while keeping all of the
> file descriptors open. This should succeed but doesn't on Btrfs without
> the fix.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>
> ---
>  tests/generic/479     |  0
>  tests/generic/487     | 65 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/487.out |  2 ++
>  tests/generic/group   |  1 +
>  4 files changed, 68 insertions(+)
>  mode change 100644 => 100755 tests/generic/479
>  create mode 100755 tests/generic/487
>  create mode 100644 tests/generic/487.out
> 
> diff --git a/tests/generic/479 b/tests/generic/479
> old mode 100644
> new mode 100755
> diff --git a/tests/generic/487 b/tests/generic/487
> new file mode 100755
> index 00000000..66379cf0
> --- /dev/null
> +++ b/tests/generic/487
> @@ -0,0 +1,65 @@
> +#! /bin/bash
> +# FS QA Test 487
> +#
> +# Test having many file descriptors referring to deleted files open. Regression
> +# test for patch "Btrfs: fix ENOSPC caused by orphan items reservations".
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2018 Omar Sandoval.  All Rights Reserved.
> +#
> +# 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.
> +#
> +# This program is distributed in the hope that it would 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, write the Free Software Foundation,
> +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> +#-----------------------------------------------------------------------
> +#
> +
> +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.*
> +}
> +
> +. ./common/rc
> +. ./common/filter
> +
> +rm -f $seqres.full
> +
> +_supported_fs generic
> +_supported_os Linux
> +_require_scratch
> +
> +_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full 2>&1
> +_scratch_mount
> +
> +test_file="$SCRATCH_MNT/$seq"
> +
> +(
> +ulimit -n $((16 * 1024))
> +# ~10000 files on a 1 GB filesystem should be no problem.
> +for ((i = 1000; i < 10000; i++)); do
> +	eval "exec $i<> \"$test_file\"" && rm "$test_file" || break
> +done

There's a helper command in src that does exactly this job, e.g.

$here/src/multi_open_unlink -f $SCRATCH_MNT/$seq -n 10000 -s 0

which creates & unlinks 10000 files and keeps them open for 0 second in
$SCRATCH_MNT using "$seq" as name prefix. This reduces the test run time
from 13s to 1s for me.

It's a straightforward change, I'll just update on commit, please let me
know if you have different thoughts.

Thanks,
Eryu

> +)
> +
> +echo "Silence is golden"
> +
> +status=0
> +exit
> diff --git a/tests/generic/487.out b/tests/generic/487.out
> new file mode 100644
> index 00000000..5f31fd97
> --- /dev/null
> +++ b/tests/generic/487.out
> @@ -0,0 +1,2 @@
> +QA output created by 487
> +Silence is golden
> diff --git a/tests/generic/group b/tests/generic/group
> index 505383f7..93581257 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -489,3 +489,4 @@
>  484 auto quick
>  485 auto quick insert
>  486 auto quick attr
> +487 auto quick
> -- 
> 2.17.0
> 

Re: [PATCH] btrfs: test ENOSPC caused by many orphan items

[Omar Sandoval]

On Wed, May 16, 2018 at 09:48:58AM +0800, Eryu Guan wrote:
> On Wed, May 09, 2018 at 11:21:55PM -0700, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > Btrfs has a bug where we can prematurely ENOSPC if we have lots of
> > orphaned files, i.e., deleted files which are still open. Add a test
> > which repeatedly creates and deletes a file while keeping all of the
> > file descriptors open. This should succeed but doesn't on Btrfs without
> > the fix.
> > 
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > ---
> >  tests/generic/479     |  0
> >  tests/generic/487     | 65 +++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/487.out |  2 ++
> >  tests/generic/group   |  1 +
> >  4 files changed, 68 insertions(+)
> >  mode change 100644 => 100755 tests/generic/479
> >  create mode 100755 tests/generic/487
> >  create mode 100644 tests/generic/487.out
> > 
> > diff --git a/tests/generic/479 b/tests/generic/479
> > old mode 100644
> > new mode 100755
> > diff --git a/tests/generic/487 b/tests/generic/487
> > new file mode 100755
> > index 00000000..66379cf0
> > --- /dev/null
> > +++ b/tests/generic/487
> > @@ -0,0 +1,65 @@
> > +#! /bin/bash
> > +# FS QA Test 487
> > +#
> > +# Test having many file descriptors referring to deleted files open. Regression
> > +# test for patch "Btrfs: fix ENOSPC caused by orphan items reservations".
> > +#
> > +#-----------------------------------------------------------------------
> > +# Copyright (c) 2018 Omar Sandoval.  All Rights Reserved.
> > +#
> > +# 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.
> > +#
> > +# This program is distributed in the hope that it would 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, write the Free Software Foundation,
> > +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> > +#-----------------------------------------------------------------------
> > +#
> > +
> > +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.*
> > +}
> > +
> > +. ./common/rc
> > +. ./common/filter
> > +
> > +rm -f $seqres.full
> > +
> > +_supported_fs generic
> > +_supported_os Linux
> > +_require_scratch
> > +
> > +_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full 2>&1
> > +_scratch_mount
> > +
> > +test_file="$SCRATCH_MNT/$seq"
> > +
> > +(
> > +ulimit -n $((16 * 1024))
> > +# ~10000 files on a 1 GB filesystem should be no problem.
> > +for ((i = 1000; i < 10000; i++)); do
> > +	eval "exec $i<> \"$test_file\"" && rm "$test_file" || break
> > +done
> 
> There's a helper command in src that does exactly this job, e.g.
> 
> $here/src/multi_open_unlink -f $SCRATCH_MNT/$seq -n 10000 -s 0
> 
> which creates & unlinks 10000 files and keeps them open for 0 second in
> $SCRATCH_MNT using "$seq" as name prefix. This reduces the test run time
> from 13s to 1s for me.
> 
> It's a straightforward change, I'll just update on commit, please let me
> know if you have different thoughts.
> 
> Thanks,
> Eryu

Great, as long as it still reproduces the bug without the fix applied,
that's perfect. Thanks!

Re: [PATCH] btrfs: test ENOSPC caused by many orphan items

[Eryu Guan]

On Tue, May 15, 2018 at 07:14:02PM -0700, Omar Sandoval wrote:
> On Wed, May 16, 2018 at 09:48:58AM +0800, Eryu Guan wrote:
> > On Wed, May 09, 2018 at 11:21:55PM -0700, Omar Sandoval wrote:
> > > From: Omar Sandoval <osandov@fb.com>
> > > 
> > > Btrfs has a bug where we can prematurely ENOSPC if we have lots of
> > > orphaned files, i.e., deleted files which are still open. Add a test
> > > which repeatedly creates and deletes a file while keeping all of the
> > > file descriptors open. This should succeed but doesn't on Btrfs without
> > > the fix.
> > > 
> > > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > > ---
> > >  tests/generic/479     |  0
> > >  tests/generic/487     | 65 +++++++++++++++++++++++++++++++++++++++++++
> > >  tests/generic/487.out |  2 ++
> > >  tests/generic/group   |  1 +
> > >  4 files changed, 68 insertions(+)
> > >  mode change 100644 => 100755 tests/generic/479
> > >  create mode 100755 tests/generic/487
> > >  create mode 100644 tests/generic/487.out
> > > 
> > > diff --git a/tests/generic/479 b/tests/generic/479
> > > old mode 100644
> > > new mode 100755
> > > diff --git a/tests/generic/487 b/tests/generic/487
> > > new file mode 100755
> > > index 00000000..66379cf0
> > > --- /dev/null
> > > +++ b/tests/generic/487
> > > @@ -0,0 +1,65 @@
> > > +#! /bin/bash
> > > +# FS QA Test 487
> > > +#
> > > +# Test having many file descriptors referring to deleted files open. Regression
> > > +# test for patch "Btrfs: fix ENOSPC caused by orphan items reservations".
> > > +#
> > > +#-----------------------------------------------------------------------
> > > +# Copyright (c) 2018 Omar Sandoval.  All Rights Reserved.
> > > +#
> > > +# 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.
> > > +#
> > > +# This program is distributed in the hope that it would 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, write the Free Software Foundation,
> > > +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> > > +#-----------------------------------------------------------------------
> > > +#
> > > +
> > > +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.*
> > > +}
> > > +
> > > +. ./common/rc
> > > +. ./common/filter
> > > +
> > > +rm -f $seqres.full
> > > +
> > > +_supported_fs generic
> > > +_supported_os Linux
> > > +_require_scratch
> > > +
> > > +_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full 2>&1
> > > +_scratch_mount
> > > +
> > > +test_file="$SCRATCH_MNT/$seq"
> > > +
> > > +(
> > > +ulimit -n $((16 * 1024))
> > > +# ~10000 files on a 1 GB filesystem should be no problem.
> > > +for ((i = 1000; i < 10000; i++)); do
> > > +	eval "exec $i<> \"$test_file\"" && rm "$test_file" || break
> > > +done
> > 
> > There's a helper command in src that does exactly this job, e.g.
> > 
> > $here/src/multi_open_unlink -f $SCRATCH_MNT/$seq -n 10000 -s 0
> > 
> > which creates & unlinks 10000 files and keeps them open for 0 second in
> > $SCRATCH_MNT using "$seq" as name prefix. This reduces the test run time
> > from 13s to 1s for me.
> > 
> > It's a straightforward change, I'll just update on commit, please let me
> > know if you have different thoughts.
> > 
> > Thanks,
> > Eryu
> 
> Great, as long as it still reproduces the bug without the fix applied,
> that's perfect. Thanks!

Yes, I've verified that it still reproduces the bug on btrfs and test
passes with the fix(es) applied.

Thanks,
Eryu