On Wed, Apr 07, 2021 at 09:10:46AM -0700, Darrick J. Wong wrote: > On Tue, Apr 06, 2021 at 03:54:29PM -0700, Boris Burkov wrote: > > btrfs trims fiemap extents to the inputted offset, which leads to > > inconsistent results for most inputs, and downright bizarre outputs like > > [7..6] when the trimmed extent is at the end of an extent and shorter > > than 512 bytes. > > > > This test covers a bunch of cases like that and ensures that file > > systems always return the full extent without trimming it. > > > > I also ran it under ext2, ext3, ext4, f2fs, and xfs successfully, but I > > suppose it's no guarantee that every file system will store a 4k synced > > write in a single extent. For that reason, this might be a bit fragile. > > Does it work with 64k fs blocks? Or 512b blocks? :) > I don't have easy access to a means of testing with 64k blocks, but I did test the more flexible v3 on 512, 1024, 2048, and 4096 byte blocks. > Also... is there an xfs_io fix to go with this? > Since the xfs_bmap manpage says that it outputs in 512 byte chunks and the xfs_io manpage says fiemap should output the full extent, I figured this was a case of garbage-in-garbage-out. Do you think xfs_io fiemap should handle these <=512 byte cases more permissively? With xfs and -b size=512, I got: 0: [0..0]: 11..11 which might really be a bug. > > > > This test is fixed for btrfs by: > > btrfs: return whole extents in fiemap > > (https://lore.kernel.org/linux-btrfs/274e5bcebdb05a8969fc300b4802f33da2fbf218.1617746680.git.boris@xxxxxx/) > > > > Signed-off-by: Boris Burkov <boris@xxxxxx> > > > > -- > > v2: fill out copyright and test description > > > > --- > > tests/generic/623 | 94 +++++++++++++++++++++++++++++++++++++++++++ > > tests/generic/623.out | 2 + > > tests/generic/group | 1 + > > 3 files changed, 97 insertions(+) > > create mode 100755 tests/generic/623 > > create mode 100644 tests/generic/623.out > > > > diff --git a/tests/generic/623 b/tests/generic/623 > > new file mode 100755 > > index 00000000..85ef68f6 > > --- /dev/null > > +++ b/tests/generic/623 > > @@ -0,0 +1,94 @@ > > +#! /bin/bash > > +# SPDX-License-Identifier: GPL-2.0 > > +# Copyright (c) 2021 Facebook. All Rights Reserved. > > +# > > +# FS QA Test 623 > > +# > > +# Test fiemaps with offsets into small parts of extents. > > +# Expect to get the whole extent, anyway. > > +# > > +seq=`basename $0` > > +seqres=$RESULT_DIR/$seq > > +echo "QA output created by $seq" > > + > > +here=`pwd` > > +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 > > + > > +# remove previous $seqres.full before test > > +rm -f $seqres.full > > + > > +# real QA test starts here > > + > > +# Modify as appropriate. > > +_supported_fs generic > > +_require_test > > +_require_scratch > > +_require_xfs_io_command "fiemap" > > + > > +rm -f $seqres.full > > + > > +_do_fiemap() { > > + off=$1 > > + len=$2 > > + $XFS_IO_PROG -c "fiemap $off $len" $SCRATCH_MNT/foo > > +} > > + > > +_check_fiemap() { > > Only helper functions in common/ need to be prefixed with "_". > > > + off=$1 > > + len=$2 > > + actual=$(_do_fiemap $off $len | tee -a $seqres.full) > > + [ "$actual" == "$expected" ] || _fail "unexpected fiemap on $off $len" > > +} > > + > > +_scratch_mkfs >>$seqres.full 2>&1 > > +_scratch_mount > > You could probably accomplish this by creating a file on the test > device, which means this test would run on configurations where there's > no scratch device; and run faster since there's no longer any need for > mkfs. > > --D > Thanks for the review, Boris > > + > > +# write a file with one extent > > +$XFS_IO_PROG -f -s -c "pwrite -S 0xcf 0 4K" $SCRATCH_MNT/foo >/dev/null > > + > > +# since the exact extent location is unpredictable especially when > > +# varying file systems, just test that they are all equal, which is > > +# what we really expect. > > +expected=$(_do_fiemap) > > + > > +# start to mid-extent > > +_check_fiemap 0 2048 > > +# start to end > > +_check_fiemap 0 4096 > > +# start to past-end > > +_check_fiemap 0 4097 > > +# mid-extent to mid-extent > > +_check_fiemap 1024 2048 > > +# mid-extent to end > > +_check_fiemap 2048 4096 > > +# mid-extent to past-end > > +_check_fiemap 2048 4097 > > + > > +# to end; len < 512 > > +_check_fiemap 4091 5 > > +# to end; len == 512 > > +_check_fiemap 3584 512 > > +# past end; len < 512 > > +_check_fiemap 4091 500 > > +# past end; len == 512 > > +_check_fiemap 4091 512 > > + > > +_scratch_unmount > > + > > +echo "Silence is golden" > > + > > +# success, all done > > +status=0 > > +exit > > diff --git a/tests/generic/623.out b/tests/generic/623.out > > new file mode 100644 > > index 00000000..6f774f19 > > --- /dev/null > > +++ b/tests/generic/623.out > > @@ -0,0 +1,2 @@ > > +QA output created by 623 > > +Silence is golden > > diff --git a/tests/generic/group b/tests/generic/group > > index b10fdea4..39e02383 100644 > > --- a/tests/generic/group > > +++ b/tests/generic/group > > @@ -625,3 +625,4 @@ > > 620 auto mount quick > > 621 auto quick encrypt > > 622 auto shutdown metadata atime > > +623 auto quick > > -- > > 2.30.2 > >
