We had a broken optimization in cephfs and netfs lib that could cause part of a page to be improperly zeroed-out when writing to an offset that was beyond the EOF but in an existing page. Add a simple test that would have caught this. Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> --- tests/generic/XXX | 53 +++++++++++++++++++++++++++++++++++++++++++ tests/generic/XXX.out | 5 ++++ tests/generic/group | 1 + 3 files changed, 59 insertions(+) create mode 100755 tests/generic/XXX create mode 100644 tests/generic/XXX.out diff --git a/tests/generic/XXX b/tests/generic/XXX new file mode 100755 index 000000000000..0ddaaa544609 --- /dev/null +++ b/tests/generic/XXX @@ -0,0 +1,53 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2021, Jeff Layton <jlayton@xxxxxxxxxx> +# +# FS QA Test No. XXX +# +# Open a file and write a little data to it. Unmount (to clean out the cache) +# and then mount again. Then write some data to it beyond the EOF and ensure +# the result is correct. Prompted by a bug in ceph_write_begin. See: +# +# https://lore.kernel.org/ceph-devel/97002.1623448034@xxxxxxxxxxxxxxxxxxxxxx/T/#m9f34b328623b493c529505e12f64f4dfdbddfb27 +# +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" + +here=`pwd` +status=1 # failure is the default! +trap "_cleanup; exit \$status" 0 1 2 3 15 + + +_cleanup() +{ + cd / + rm -f $testfile +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter + +_supported_fs generic +_require_test + +rm -f $seqres.full + +testfile="$TEST_DIR/test_write_begin.$$" + +# write some data to file and fsync it out +$XFS_IO_PROG -f -c "pwrite -q 0 32" $testfile + +# cycle the mount to clean out the pagecache +_test_cycle_mount + +# now, write to the file (near the end) +$XFS_IO_PROG -c "pwrite -q 32 32" $testfile + +# dump what we think is in there +echo "The result should be 64 bytes filled with 0xcd:" +hexdump -C $testfile + +status=0 +exit diff --git a/tests/generic/XXX.out b/tests/generic/XXX.out new file mode 100644 index 000000000000..4e7653858e51 --- /dev/null +++ b/tests/generic/XXX.out @@ -0,0 +1,5 @@ +QA output created by XXX +The result should be 64 bytes filled with 0xcd: +00000000 cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd |................| +* +00000040 diff --git a/tests/generic/group b/tests/generic/group index 9a636b23f243..204a9b548f78 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -641,3 +641,4 @@ 636 auto quick swap 637 auto quick dir 638 auto quick rw +XXX auto quick rw -- 2.31.1
