From: Filipe Manana <fdmanana@xxxxxxxx>
Verify some attempts to write into a file using RWF_NOWAIT:
1) Writing into a fallocated extent that starts at eof should work;
2) Writing into a hole should fail;
3) Writing into a range that is partially allocated should fail.
This is motivated by several bugs that btrfs and ext4 had and were fixed
by the following kernel commits:
4b1946284dd6 ("btrfs: fix failure of RWF_NOWAIT write into prealloc extent beyond eof")
260a63395f90 ("btrfs: fix RWF_NOWAIT write not failling when we need to cow")
0b3171b6d195 ("ext4: do not block RWF_NOWAIT dio write on unallocated space")
At the moment, on a 5.9-rc6 kernel at least, ext4 is failing for case 1),
but when I found and fixed case 1) in btrfs, around kernel 5.7, it was not
failing on ext4, so some regression happened in the meanwhile. For xfs and
btrfs on a 5.9 kernel, all the three cases pass.
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
---
tests/generic/613 | 74 +++++++++++++++++++++++++++++++++++++++++++
tests/generic/613.out | 19 +++++++++++
tests/generic/group | 1 +
3 files changed, 94 insertions(+)
create mode 100755 tests/generic/613
create mode 100644 tests/generic/613.out
diff --git a/tests/generic/613 b/tests/generic/613
new file mode 100755
index 00000000..931876dc
--- /dev/null
+++ b/tests/generic/613
@@ -0,0 +1,74 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2020 SUSE Linux Products GmbH. All Rights Reserved.
+#
+# FS QA Test No. 613
+#
+# Verify some attempts to write into a file using RWF_NOWAIT:
+#
+# 1) Writing into a fallocated extent that starts at eof should work;
+# 2) Writing into a hole should fail;
+# 3) Writing into a range that is partially allocated should fail.
+#
+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 generic
+_require_scratch
+_require_odirect
+_require_xfs_io_command pwrite -N
+_require_xfs_io_command falloc -k
+_require_xfs_io_command fpunch
+
+rm -f $seqres.full
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+echo "Creating file"
+$XFS_IO_PROG -f -d -c "pwrite -S 0xab 0 512K" $SCRATCH_MNT/foo | _filter_xfs_io
+
+# Now add an unwritten extent using fallocate without bumping the file size and
+# then attempt to do a RWF_NOWAIT write into this extent. It should not fail.
+echo "Writing into fallocated extent at eof"
+$XFS_IO_PROG -c "falloc -k 512K 512K" \
+ -d -c "pwrite -N -V 1 -S 0xcd -b 512K 512K 512K" \
+ $SCRATCH_MNT/foo | _filter_xfs_io
+
+# Now punch a hole and try a RWF_NOWAIT write into the hole. It should fail.
+echo "Writing into a hole"
+$XFS_IO_PROG -c "fpunch 0 256K" \
+ -d -c "pwrite -N -V 1 -S 0xff -b 128K 0 128K" \
+ $SCRATCH_MNT/foo | _filter_xfs_io
+
+# Allocate an extent for the first half of the hole, then attempt to write into
+# a range that covers the new extent and the hole. It should fail.
+echo "Writing into a range partially allocated (ending with a hole)"
+$XFS_IO_PROG -c "falloc 0 128K" \
+ -d -c "pwrite -N -V 1 -S 0xef -b 256K 0 256K" \
+ $SCRATCH_MNT/foo | _filter_xfs_io
+
+# Just double check none of the writes above that should fail did not change the
+# file data in an unexpected way. First 256K of file data should be all zeros,
+# the range from 256K to 512K should have all bytes with a value of 0xab and the
+# range from 512K to 1M should have all bytes with a value of 0xcd.
+echo "Final file content:"
+od -A d -t x1 $SCRATCH_MNT/foo
+
+status=0
+exit
diff --git a/tests/generic/613.out b/tests/generic/613.out
new file mode 100644
index 00000000..a542fa5b
--- /dev/null
+++ b/tests/generic/613.out
@@ -0,0 +1,19 @@
+QA output created by 613
+Creating file
+wrote 524288/524288 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Writing into fallocated extent at eof
+wrote 524288/524288 bytes at offset 524288
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Writing into a hole
+pwrite: Resource temporarily unavailable
+Writing into a range partially allocated (ending with a hole)
+pwrite: Resource temporarily unavailable
+Final file content:
+0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+*
+0262144 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab
+*
+0524288 cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd
+*
+1048576
diff --git a/tests/generic/group b/tests/generic/group
index 8054d874..b8bf8ec1 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -615,3 +615,4 @@
610 auto quick prealloc zero
611 auto quick attr
612 auto quick clone
+613 auto quick rw prealloc punch
--
2.28.0
