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/639 | 39 +++++++++++++++++++++++++++++++++++++++ tests/generic/639.out | 5 +++++ 2 files changed, 44 insertions(+) create mode 100755 tests/generic/639 create mode 100644 tests/generic/639.out v3: adapt to new test template diff --git a/tests/generic/639 b/tests/generic/639 new file mode 100755 index 000000000000..c30f7644a2fc --- /dev/null +++ b/tests/generic/639 @@ -0,0 +1,39 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2021, Jeff Layton <jlayton@xxxxxxxxxx> +# +# FS QA Test No. 639 +# +# 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 that was fixed by commit 827a746f405d. +# +. ./common/preamble +_begin_fstest auto quick rw + +# Import common functions. +. ./common/filter + +# real QA test starts here +_supported_fs generic +_require_test + +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/639.out b/tests/generic/639.out new file mode 100644 index 000000000000..9bf0bac96864 --- /dev/null +++ b/tests/generic/639.out @@ -0,0 +1,5 @@ +QA output created by 639 +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 -- 2.31.1
