btrfs: test unaligned punch hole at ENOSPC

Try to punch hole with unaligned size and offset when the FS is full
and mounted with nodatacow option.

Mainly holes are punched at locations which are unaligned with the
file extent boundaries when the FS is full by data.  As the punching
holes at unaligned location will involve truncating blocks instead
of just dropping the extents, it shall involve reserving data and
metadata space for delalloc and so data alloc fails as the FS is
full.

btrfs_punch_hole()
 btrfs_truncate_block()
   btrfs_check_data_free_space() <-- ENOSPC

We don't fail punch hole if the holes are aligned with the file
extent boundaries as it shall involve just dropping the related
extents, without truncating data extent blocks.

This test was orignally merged as btrfs/172 (commit 4c2c678cd), then
Iremoved by commit 538d8a4bcc78. But it's decided to bring back this
test case, now the problem is better understood and the fix is
available in the ML as below.

Link: https://patchwork.kernel.org/patch/11357415/
Reviewed-by: Filipe Manana <fdmanana@suse.com>
(cherry picked from commit 4c2c678cd56a81a210cb16f9f9347073e91e2fb0)
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

diff --git a/tests/btrfs/204 b/tests/btrfs/204
new file mode 100755 (executable)
index 0000000..bc5f773
--- /dev/null
+++ b/tests/btrfs/204
@@ -0,0 +1,73 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2018 Oracle. All Rights Reserved.
+#
+# FS QA Test 204
+#
+# Test if the unaligned (by size and offset) punch hole is successful when FS
+# is at ENOSPC.
+#
+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
+_require_xfs_io_command "fpunch"
+
+_scratch_mkfs_sized $((256 * 1024 *1024)) >> $seqres.full
+
+# max_inline ensures data is not inlined within metadata extents
+_scratch_mount "-o max_inline=0,nodatacow"
+
+cat /proc/self/mounts | grep $SCRATCH_DEV >> $seqres.full
+$BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT >> $seqres.full
+
+extent_size=$(_scratch_btrfs_sectorsize)
+unalign_by=512
+echo extent_size=$extent_size unalign_by=$unalign_by >> $seqres.full
+
+$XFS_IO_PROG -f -c "pwrite -S 0xab 0 $((extent_size * 10))" \
+                                       $SCRATCH_MNT/testfile >> $seqres.full
+
+echo "Fill all space available for data and all unallocated space." >> $seqres.full
+dd status=none if=/dev/zero of=$SCRATCH_MNT/filler bs=512 >> $seqres.full 2>&1
+
+hole_offset=0
+hole_len=$unalign_by
+$XFS_IO_PROG -c "fpunch $hole_offset $hole_len" $SCRATCH_MNT/testfile
+
+hole_offset=$(($extent_size + $unalign_by))
+hole_len=$(($extent_size - $unalign_by))
+$XFS_IO_PROG -c "fpunch $hole_offset $hole_len" $SCRATCH_MNT/testfile
+
+hole_offset=$(($extent_size * 2 + $unalign_by))
+hole_len=$(($extent_size * 5))
+$XFS_IO_PROG -c "fpunch $hole_offset $hole_len" $SCRATCH_MNT/testfile
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit

diff --git a/tests/btrfs/204.out b/tests/btrfs/204.out
new file mode 100644 (file)
index 0000000..1035eae
--- /dev/null
+++ b/tests/btrfs/204.out
@@ -0,0 +1,2 @@
+QA output created by 204
+Silence is golden

diff --git a/tests/btrfs/group b/tests/btrfs/group
index 6acc64263cd557d37e8024742f188922ff568d61..1947f0d7fa8f1e236e0d4d156d4941925c0435a0 100644 (file)
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -206,3 +206,4 @@
 201 auto quick punch log
 202 auto quick subvol snapshot
 203 auto quick send clone
+204 auto quick punch