overlay/016: split into two tests

overlay/016 tests two cases of ro/rw fd data inconsistecies -
one using pread and one using mmap read (i.e. mread).

The first case now passes with stacked overlay file operations
patch set merged. The second case will still fail.

By splitting the two test cases we get one regression test for
the common case of ro/rw fd data inconsistecy with pread and
one test to track the remaining non-standard behavior of
overlayfs w.r.t mmap.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

tests/overlay/016

@@ -43,13 +43,11 @@ _scratch_mkfs >>$seqres.full 2>&1
 lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
 mkdir -p $lowerdir
 echo "This is old news" > $lowerdir/foo
-echo "This is old news" > $lowerdir/bar
 
 _scratch_mount
 
 
 #
-# case #1:
 # open file for read (rofd)
 # open file for write (rwfd)
 # write to rwfd
@@ -62,18 +60,5 @@ $XFS_IO_PROG -r $SCRATCH_MNT/foo \
 	-C "pread -v 0 16" \
 | _filter_xfs_io | _filter_scratch
 
-#
-# case #2:
-# mmap MAP_SHARED|PROT_READ of rofd
-# write to rwfd
-# read from mapped memory
-#
-$XFS_IO_PROG -r $SCRATCH_MNT/bar \
-	-C "mmap -r 0 16" \
-	-C "open $SCRATCH_MNT/bar" \
-	-C "pwrite -S 0x61 0 16" \
-	-C "mread -v 0 16" \
-| _filter_xfs_io | _filter_scratch
-
 status=0
 exit

tests/overlay/016.out

@@ -6,6 +6,3 @@ XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 00000000:  61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61  aaaaaaaaaaaaaaaa
 read 16/16 bytes at offset 0
 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-wrote 16/16 bytes at offset 0
-XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-00000000:  61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61  aaaaaaaaaaaaaaaa

tests/overlay/061

@@ -0,0 +1,65 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2018 CTERA Networks. All Rights Reserved.
+#
+# FSQA Test No. 061
+#
+# Test ro/rw fd data inconsistecies
+#
+# This is a variant of test overlay/016 with mread instead of pread.
+#
+# This simple test demonstrates a known issue with overlayfs:
+# - process A opens file F for read + mmap
+# - process B writes new data to file F
+# - process A reads old data from mapped memory
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+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
+
+# real QA test starts here
+_supported_fs overlay
+_supported_os Linux
+_require_scratch
+_require_xfs_io_command "open"
+
+rm -f $seqres.full
+
+_scratch_mkfs >>$seqres.full 2>&1
+
+# Create our test files.
+lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
+mkdir -p $lowerdir
+echo "This is old news" > $lowerdir/foo
+
+_scratch_mount
+
+
+#
+# mmap MAP_SHARED|PROT_READ of rofd
+# write to rwfd
+# read from mapped memory
+#
+$XFS_IO_PROG -r $SCRATCH_MNT/foo \
+	-C "mmap -r 0 16" \
+	-C "open $SCRATCH_MNT/foo" \
+	-C "pwrite -S 0x61 0 16" \
+	-C "mread -v 0 16" \
+| _filter_xfs_io | _filter_scratch
+
+status=0
+exit

tests/overlay/061.out

@@ -0,0 +1,4 @@
+QA output created by 061
+wrote 16/16 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+00000000:  61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61  aaaaaaaaaaaaaaaa

tests/overlay/group

@@ -63,3 +63,4 @@
 058 auto quick exportfs
 059 auto quick copyup
 060 auto quick metacopy
+061 auto quick copyup