Re: [PATCH v3] fstests: regression test for btrfs buffered read's repair

[Filipe Manana]

On Fri, Apr 28, 2017 at 6:26 PM, Liu Bo  wrote:
> This case tests whether buffered read can repair the bad copy if we
> have a good copy.
>
> Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed
> and drop checks") introduced the regression.
>
> The upstream fix is
> Btrfs: bring back repair during read
>
> Signed-off-by: Liu Bo 

Reviewed-by: Filipe Manana 

Just a comment below.

> ---
> v2: - Add regression commit and the fix to the description
> - Use btrfs inspect-internal dump-tree to get rid of the dependence 
> btrfs-map-logical
> - Add comments in several places
> - Fix typo, dio->buffered.
>
> v3: - Add 'mkfs -b 1G' to limit filesystem size to 2G in raid1 profile so that
>   we get a consistent output.
>
>  tests/btrfs/141 | 169 
> 
>  tests/btrfs/141.out |  39 
>  tests/btrfs/group   |   1 +
>  3 files changed, 209 insertions(+)
>  create mode 100755 tests/btrfs/141
>  create mode 100644 tests/btrfs/141.out
>
> diff --git a/tests/btrfs/141 b/tests/btrfs/141
> new file mode 100755
> index 000..c4e08ed
> --- /dev/null
> +++ b/tests/btrfs/141
> @@ -0,0 +1,169 @@
> +#! /bin/bash
> +# FS QA Test 141
> +#
> +# Regression test for btrfs buffered read's repair during read.
> +#
> +# Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed
> +# and drop checks") introduced the regression.
> +#
> +# The upstream fix is
> +#  Btrfs: bring back repair during read
> +#
> +#---
> +# Copyright (c) 2017 Liu Bo.  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.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_supported_fs btrfs
> +_supported_os Linux
> +_require_scratch_dev_pool 2
> +
> +_require_btrfs_command inspect-internal dump-tree
> +_require_command "$FILEFRAG_PROG" filefrag
> +
> +
> +# helpe to convert 'file offset' to btrfs logical offset
> +FILEFRAG_FILTER='
> +   if (/blocks? of (\d+) bytes/) {
> +   $blocksize = $1;
> +   next
> +   }
> +   ($ext, $logical, $physical, $length) =
> +   (/^\s*(\d+):\s+(\d+)..\s+\d+:\s+(\d+)..\s+\d+:\s+(\d+):/)
> +   or next;
> +   ($flags) = /.*:\s*(\S*)$/;
> +   print $physical * $blocksize, "#",
> + $length * $blocksize, "#",
> + $logical * $blocksize, "#",
> + $flags, " "'
> +
> +# this makes filefrag output script readable by using a perl helper.
> +# output is one extent per line, with three numbers separated by '#'
> +# the numbers are: physical, length, logical (all in bytes)
> +# sample output: "1234#10#5678" -> physical 1234, length 10, logical 5678
> +_filter_extents()
> +{
> +   tee -a $seqres.full | $PERL_PROG -ne "$FILEFRAG_FILTER"
> +}
> +
> +_check_file_extents()
> +{
> +   cmd="filefrag -v $1"
> +   echo "# $cmd" >> $seqres.full
> +   out=`$cmd | _filter_extents`
> +   if [ -z "$out" ]; then
> +   return 1
> +   fi
> +   echo "after filter: $out" >> $seqres.full
> +   echo $out
> +   return 0
> +}
> +
> +_check_repair()
> +{
> +   filter=${1:-cat}
> +   dmesg | tac | sed -ne "0,\#run fstests $seqnum at $date_time#p" | tac 
> | $filter | grep -q -e "csum failed"
> +   if [ $? -eq 0 ]; then
> +   echo 1
> +   else
> +   echo 0
> +   fi
> +}
> +
> +_get_physical()
> +{
> +# $1 is logical address
> +# print chunk tree and find devid 2 which is $SCRATCH_DEV
> +$BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 $SCRATCH_DEV | grep 
> $1 -A 6 | awk '($1 ~ /stripe/ && $3 ~ /devid/ && $4 ~ /1/) { print $6 }'
> +}
> +
> 

[PATCH v3] fstests: regression test for btrfs buffered read's repair

[Liu Bo]

This case tests whether buffered read can repair the bad copy if we
have a good copy.

Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed
and drop checks") introduced the regression.

The upstream fix is
Btrfs: bring back repair during read

Signed-off-by: Liu Bo 
---
v2: - Add regression commit and the fix to the description
- Use btrfs inspect-internal dump-tree to get rid of the dependence 
btrfs-map-logical
- Add comments in several places
- Fix typo, dio->buffered.

v3: - Add 'mkfs -b 1G' to limit filesystem size to 2G in raid1 profile so that
  we get a consistent output.

 tests/btrfs/141 | 169 
 tests/btrfs/141.out |  39 
 tests/btrfs/group   |   1 +
 3 files changed, 209 insertions(+)
 create mode 100755 tests/btrfs/141
 create mode 100644 tests/btrfs/141.out

diff --git a/tests/btrfs/141 b/tests/btrfs/141
new file mode 100755
index 000..c4e08ed
--- /dev/null
+++ b/tests/btrfs/141
@@ -0,0 +1,169 @@
+#! /bin/bash
+# FS QA Test 141
+#
+# Regression test for btrfs buffered read's repair during read.
+#
+# Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed
+# and drop checks") introduced the regression.
+#
+# The upstream fix is
+#  Btrfs: bring back repair during read
+#
+#---
+# Copyright (c) 2017 Liu Bo.  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.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch_dev_pool 2
+
+_require_btrfs_command inspect-internal dump-tree
+_require_command "$FILEFRAG_PROG" filefrag
+
+
+# helpe to convert 'file offset' to btrfs logical offset
+FILEFRAG_FILTER='
+   if (/blocks? of (\d+) bytes/) {
+   $blocksize = $1;
+   next
+   }
+   ($ext, $logical, $physical, $length) =
+   (/^\s*(\d+):\s+(\d+)..\s+\d+:\s+(\d+)..\s+\d+:\s+(\d+):/)
+   or next;
+   ($flags) = /.*:\s*(\S*)$/;
+   print $physical * $blocksize, "#",
+ $length * $blocksize, "#",
+ $logical * $blocksize, "#",
+ $flags, " "'
+
+# this makes filefrag output script readable by using a perl helper.
+# output is one extent per line, with three numbers separated by '#'
+# the numbers are: physical, length, logical (all in bytes)
+# sample output: "1234#10#5678" -> physical 1234, length 10, logical 5678
+_filter_extents()
+{
+   tee -a $seqres.full | $PERL_PROG -ne "$FILEFRAG_FILTER"
+}
+
+_check_file_extents()
+{
+   cmd="filefrag -v $1"
+   echo "# $cmd" >> $seqres.full
+   out=`$cmd | _filter_extents`
+   if [ -z "$out" ]; then
+   return 1
+   fi
+   echo "after filter: $out" >> $seqres.full
+   echo $out
+   return 0
+}
+
+_check_repair()
+{
+   filter=${1:-cat}
+   dmesg | tac | sed -ne "0,\#run fstests $seqnum at $date_time#p" | tac | 
$filter | grep -q -e "csum failed"
+   if [ $? -eq 0 ]; then
+   echo 1
+   else
+   echo 0
+   fi
+}
+
+_get_physical()
+{
+# $1 is logical address
+# print chunk tree and find devid 2 which is $SCRATCH_DEV
+$BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 $SCRATCH_DEV | grep 
$1 -A 6 | awk '($1 ~ /stripe/ && $3 ~ /devid/ && $4 ~ /1/) { print $6 }'
+}
+
+_scratch_dev_pool_get 2
+# step 1, create a raid1 btrfs which contains one 128k file.
+echo "step 1..mkfs.btrfs" >>$seqres.full
+
+mkfs_opts="-d raid1 -b 1G"
+_scratch_pool_mkfs $mkfs_opts >>$seqres.full 2>&1
+
+# -o nospace_cache makes sure data is written to the start position of the data
+# chunk
+_scratch_mount -o nospace_cache
+
+$XFS_IO_PROG -f -d -c "pwrite -S 0xaa -b 128K 0 128K" "$SCRATCH_MNT/foobar" | 
_filter_xfs_io
+
+sync
+
+# step 2, corrupt