[v3,01/17] generic: add mmap CoW test for ranges of two shared files

Commit Message

Shiyang Ruan Dec. 14, 2021, 8:18 a.m. UTC

Ensuring that copy on write in mmap mode works when the CoW range originally
covers multiple extents. (MMAP version of generic/185,183)

Signed-off-by: Shiyang Ruan <[e-mail]>
Reviewed-by: Darrick J. Wong <[e-mail]>
---
 tests/generic/900     | 69 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/900.out | 14 +++++++++
 2 files changed, 83 insertions(+)
 create mode 100755 tests/generic/900
 create mode 100644 tests/generic/900.out

Patch

diff --git a/tests/generic/900 b/tests/generic/900
new file mode 100755
index 00000000..de76cd00
--- /dev/null
+++ b/tests/generic/900
@@ -0,0 +1,69 @@ 
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# FS QA Test No. 900
+#
+# Ensuring that copy on write in mmap mode works when the CoW
+# range originally covers multiple extents. (MMAP version of generic/185,183)
+#   - Create two files
+#   - Reflink the odd blocks of the first file into a third file.
+#   - Reflink the even blocks of the second file into the third file.
+#   - mmap CoW across the halfway mark.
+#   - 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
+
+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))
+_pwrite_byte 0x61 0 $filesize $testdir/file1 >> $seqres.full
+_pwrite_byte 0x62 0 $filesize $testdir/file2 >> $seqres.full
+seq 0 2 $((nr-1)) | while read f; do
+	_reflink_range $testdir/file1 $((blksz * f)) $testdir/file3 $((blksz * f)) $blksz >> $seqres.full
+	_pwrite_byte 0x61 $((blksz * f)) $blksz $testdir/file3.chk >> $seqres.full
+done
+seq 1 2 $((nr-1)) | while read f; do
+	_reflink_range $testdir/file2 $((blksz * f)) $testdir/file3 $((blksz * f)) $blksz >> $seqres.full
+	_pwrite_byte 0x62 $((blksz * f)) $blksz $testdir/file3.chk >> $seqres.full
+done
+_scratch_cycle_mount
+
+echo "Compare files"
+md5sum $testdir/file1 | _filter_scratch
+md5sum $testdir/file2 | _filter_scratch
+md5sum $testdir/file3 | _filter_scratch
+md5sum $testdir/file3.chk | _filter_scratch
+
+echo "mmap CoW across the transition"
+cowoff=$((filesize / 4))
+cowsz=$((filesize / 2))
+mmapsz=$((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/file2 | _filter_scratch
+md5sum $testdir/file3 | _filter_scratch
+md5sum $testdir/file3.chk | _filter_scratch
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/900.out b/tests/generic/900.out
new file mode 100644
index 00000000..b2569ab0
--- /dev/null
+++ b/tests/generic/900.out
@@ -0,0 +1,14 @@ 
+QA output created by 900
+Format and mount
+Create the original files
+Compare files
+bdbcf02ee0aa977795a79d25fcfdccb1  SCRATCH_MNT/test-900/file1
+b83f9394092e15bdcda585cd8e776dc6  SCRATCH_MNT/test-900/file2
+d3959a68638c50af07f0258e032cb554  SCRATCH_MNT/test-900/file3
+d3959a68638c50af07f0258e032cb554  SCRATCH_MNT/test-900/file3.chk
+mmap CoW across the transition
+Compare files
+bdbcf02ee0aa977795a79d25fcfdccb1  SCRATCH_MNT/test-900/file1
+b83f9394092e15bdcda585cd8e776dc6  SCRATCH_MNT/test-900/file2
+55968a95dfc0120df4e8485576514320  SCRATCH_MNT/test-900/file3
+55968a95dfc0120df4e8485576514320  SCRATCH_MNT/test-900/file3.chk