[PATCH 06/13] generic: add mmap CoW test for mixed&destination extents

[Shiyang Ruan <ruansy.fnst@fujitsu.com>]

Ensuring that copy on write in mmap mode works when the CoW range originally
covers multiple extents, mixed with reflinked, unwritten, hole, regular and
delalloc blocks.
(MMAP version of generic/200,199)

Also, add a check to make sure the delalloc block accutally exists.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
 common/reflink        |  3 ++
 tests/generic/914     | 68 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/914.out | 12 ++++++++
 3 files changed, 83 insertions(+)
 create mode 100755 tests/generic/914
 create mode 100644 tests/generic/914.out

diff --git a/common/reflink b/common/reflink
index 38210673..84173d59 100644
--- a/common/reflink
+++ b/common/reflink
@@ -362,6 +362,9 @@ _weave_reflink_rainbow_delalloc() {
 		_pwrite_byte 0x62 $((blksz * i)) $blksz $dfile
 		_pwrite_byte 0x62 $((blksz * i)) $blksz $dfile.chk
 	done
+	# make sure we actually got delalloc block
+	$FILEFRAG_PROG -v $dfile 2>&1 | grep -q delalloc || \
+		_notrun "test requires delayed allocation writes"
 }
 
 # Make the source file have interleaved regular blocks and reflinked blocks
diff --git a/tests/generic/914 b/tests/generic/914
new file mode 100755
index 00000000..211f6f26
--- /dev/null
+++ b/tests/generic/914
@@ -0,0 +1,68 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. xxx
+#
+# Ensuring that copy on write in mmap mode works when the CoW
+# range originally covers multiple extents, mixed with reflinked, unwritten,
+# hole, regular and delalloc blocks.
+# (MMAP version of generic/200,199)
+#   - Create a file with the following repeating sequence of blocks:
+#     1. reflinked
+#     2. unwritten
+#     3. hole
+#     4. regular block
+#     5. delalloc
+#   - mmap CoW across the halfway mark, starting with the unwritten extent.
+#   - Check that the files are now different where we say they're different.
+#
+. ./common/preamble
+_begin_fstest auto quick clone punch
+
+# Import common functions.
+. ./common/filter
+. ./common/reflink
+
+# real QA test starts here
+_require_scratch_reflink
+_require_xfs_io_command "falloc"
+_require_xfs_io_command "fpunch"
+_require_cp_reflink
+_require_odirect
+
+echo "Format and mount"
+_scratch_mkfs > $seqres.full 2>&1
+_scratch_mount >> $seqres.full 2>&1
+
+testdir=$SCRATCH_MNT/test-$seq
+mkdir $testdir
+
+echo "Create the original files"
+blksz=65536
+nr=64
+filesize=$((blksz * nr))
+_weave_reflink_rainbow $blksz $nr $testdir/file1 $testdir/file3 >> $seqres.full
+_scratch_cycle_mount
+
+echo "Compare files"
+md5sum $testdir/file1 | _filter_scratch
+md5sum $testdir/file3 | _filter_scratch
+md5sum $testdir/file3.chk | _filter_scratch
+
+echo "mmap CoW across the transition"
+cowoff=$((filesize / 4))
+cowsz=$((filesize / 2))
+_weave_reflink_rainbow_delalloc $blksz $nr $testdir/file3 >> $seqres.full
+# now cow
+mmapsz=$((cowoff + cowsz))
+_mwrite_byte 0x63 $cowoff $cowsz $mmapsz $testdir/file3 >> $seqres.full
+_mwrite_byte 0x63 $cowoff $cowsz $mmapsz $testdir/file3.chk >> $seqres.full
+_scratch_cycle_mount
+
+echo "Compare files"
+md5sum $testdir/file1 | _filter_scratch
+md5sum $testdir/file3 | _filter_scratch
+md5sum $testdir/file3.chk | _filter_scratch
+
+# success, all done
+status=0
diff --git a/tests/generic/914.out b/tests/generic/914.out
new file mode 100644
index 00000000..a8118a02
--- /dev/null
+++ b/tests/generic/914.out
@@ -0,0 +1,12 @@
+QA output created by 914
+Format and mount
+Create the original files
+Compare files
+bdbcf02ee0aa977795a79d25fcfdccb1  SCRATCH_MNT/test-914/file1
+6366fd359371414186688a0ef6988893  SCRATCH_MNT/test-914/file3
+6366fd359371414186688a0ef6988893  SCRATCH_MNT/test-914/file3.chk
+mmap CoW across the transition
+Compare files
+bdbcf02ee0aa977795a79d25fcfdccb1  SCRATCH_MNT/test-914/file1
+26aa3a0749b867ec58363c8539ee5471  SCRATCH_MNT/test-914/file3
+26aa3a0749b867ec58363c8539ee5471  SCRATCH_MNT/test-914/file3.chk
-- 
2.33.0