[PATCH 10/13] generic: add mmap CoW test for delalloc&source extents

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

Ensuring that copy on write in mmap mode to the source file when the CoW range
covers delalloc blocks and regular shared blocks.
(MMAP version of generic/293,295)

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
 common/reflink        |  3 ++
 tests/generic/918     | 64 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/918.out | 12 ++++++++
 3 files changed, 79 insertions(+)
 create mode 100755 tests/generic/918
 create mode 100644 tests/generic/918.out

diff --git a/common/reflink b/common/reflink
index 84173d59..e304ddc8 100644
--- a/common/reflink
+++ b/common/reflink
@@ -431,4 +431,7 @@ _sweave_reflink_holes_delalloc() {
 		_pwrite_byte 0x64 $((blksz * i)) $blksz $sfile
 		_pwrite_byte 0x64 $((blksz * i)) $blksz $sfile.chk
 	done
+	# make sure we actually got delalloc block
+	$FILEFRAG_PROG -v $sfile 2>&1 | grep -q delalloc || \
+		_notrun "test requires delayed allocation writes"
 }
diff --git a/tests/generic/918 b/tests/generic/918
new file mode 100755
index 00000000..f7767a8e
--- /dev/null
+++ b/tests/generic/918
@@ -0,0 +1,64 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. xxx
+#
+# Ensuring that copy on write in mmap mode to the source file when the
+# CoW range covers delalloc blocks and regular shared blocks.
+# (MMAP version of generic/293,295)
+#   - Create two files.
+#   - Truncate the first file.
+#   - Write the odd blocks of the first file.
+#   - Reflink the odd blocks of the first file into the second file.
+#   - Write the even blocks of the first file.
+#   - mmap CoW the first file across the halfway mark, starting with the
+#     regular extent.
+#   - Check that the files are now different where we say they're different.
+#
+. ./common/preamble
+_begin_fstest auto quick clone
+
+# Import common functions.
+. ./common/filter
+. ./common/reflink
+
+# real QA test starts here
+_require_scratch_reflink
+_require_xfs_io_command "falloc"
+
+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))
+_sweave_reflink_holes $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 $testdir/file1.chk | _filter_scratch
+
+echo "mmap CoW across the transition"
+cowoff=$((filesize / 4))
+cowsz=$((filesize / 2))
+_sweave_reflink_holes_delalloc $blksz $nr $testdir/file1 >> $seqres.full
+mmapsz=$((cowoff + cowsz))
+_mwrite_byte 0x63 $cowoff $cowsz $mmapsz $testdir/file1 >> $seqres.full
+_mwrite_byte 0x63 $cowoff $cowsz $mmapsz $testdir/file1.chk >> $seqres.full
+_scratch_cycle_mount
+
+echo "Compare files"
+md5sum $testdir/file1 | _filter_scratch
+md5sum $testdir/file3 | _filter_scratch
+md5sum $testdir/file1.chk | _filter_scratch
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/918.out b/tests/generic/918.out
new file mode 100644
index 00000000..465ade08
--- /dev/null
+++ b/tests/generic/918.out
@@ -0,0 +1,12 @@
+QA output created by 918
+Format and mount
+Create the original files
+Compare files
+b8a8a88d4c143f79900c4b4e79aa3e37  SCRATCH_MNT/test-918/file1
+ce2023f765eba19677517c511886d5c9  SCRATCH_MNT/test-918/file3
+b8a8a88d4c143f79900c4b4e79aa3e37  SCRATCH_MNT/test-918/file1.chk
+mmap CoW across the transition
+Compare files
+35e2170e14665b780c6dec328d6a263b  SCRATCH_MNT/test-918/file1
+ce2023f765eba19677517c511886d5c9  SCRATCH_MNT/test-918/file3
+35e2170e14665b780c6dec328d6a263b  SCRATCH_MNT/test-918/file1.chk
-- 
2.33.0