On Fri, Jul 02, 2021 at 09:40:24AM -0400, Jeff Layton wrote: > 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" $testfile Looks good to me, if you've used this case to reproduce that issue. Just one question, the comment says "fsync it out", does that mean we need an explicit "fsync" call (e.g. -c "pwrite -q 0 32" -c "fsync") to reproduce this bug? Or there's an implicit "fsync" somewhere? Thanks, Zorro > + > +# cycle the mount to clean out the pagecache > +_test_cycle_mount > + > +# now, write to the file (near the end) > +$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 >
