FYI, we noticed the following commit (built with gcc-7):

commit: 0d8bb3f4adaf37c269cdf50a92ef09da0bc72945 ("xfs: force writes to delalloc regions to unwritten")
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git btree-fixes

in testcase: xfstests
with following parameters:

	disk: 4HDD
	fs: xfs
	test: generic-group11

test-description: xfstests is a regression test suite for xfs and other files ystems.
test-url: git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git


on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):

If you fix the issue, kindly add following tag
Reported-by: kernel test robot <oliver.sang@intel.com>

[  184.003104] Filesystem "vdd": reserve blocks depleted! Consider increasing reserve pool size.
[  184.003296] XFS (vdd): writeback error on sector 901104
[  184.048996] XFS (vdd): writeback error on sector 897152
[  184.078819] XFS (vdd): writeback error on sector 894936
[  184.097041] XFS (vdd): writeback error on sector 954424
[  184.120100] XFS (vdd): writeback error on sector 950240
[  184.136399] XFS (vdd): writeback error on sector 962656
[  184.146385] XFS (vdd): writeback error on sector 966808
[  184.159505] XFS (vdd): writeback error on sector 979760
[  184.167936] XFS (vdd): writeback error on sector 988760
[  184.182198] XFS (vdd): writeback error on sector 1014832
[  189.195647] xfs_destroy_ioend: 9 callbacks suppressed
[  189.195655] XFS (vdd): writeback error on sector 2093336
[  189.220843] XFS (vdd): writeback error on sector 2093344
[  189.271907] XFS (vdd): writeback error on sector 2093352



2019-10-27 21:52:11 export TEST_DIR=/fs/vda
2019-10-27 21:52:11 export TEST_DEV=/dev/vda
2019-10-27 21:52:11 export FSTYP=xfs
2019-10-27 21:52:11 export SCRATCH_MNT=/fs/scratch
2019-10-27 21:52:11 mkdir /fs/scratch -p
2019-10-27 21:52:11 export SCRATCH_DEV=/dev/vdd
2019-10-27 21:52:11 export SCRATCH_LOGDEV=/dev/vdb
meta-data=/dev/vda               isize=512    agcount=4, agsize=16777216 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1
data     =                       bsize=4096   blocks=67108864, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=32768, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
2019-10-27 21:52:12 export MKFS_OPTIONS=-mreflink=1
2019-10-27 21:52:12 sed "s:^:generic/:" //lkp/benchmarks/xfstests/tests/generic-group11
2019-10-27 21:52:12 ./check generic/216 generic/217 generic/218 generic/219 generic/220 generic/221 generic/222 generic/224 generic/225 generic/226 generic/227 generic/228 generic/229 generic/230 generic/232 generic/233 generic/234
FSTYP         -- xfs (debug)
PLATFORM      -- Linux/x86_64 vm-snb-ba05e58b4c0e 5.4.0-rc3-00002-g0d8bb3f4adaf3 #1 SMP Sun Oct 27 21:35:47 CST 2019
MKFS_OPTIONS  -- -f -mreflink=1 /dev/vdd
MOUNT_OPTIONS -- /dev/vdd /fs/scratch

generic/216	 20s
generic/217	 14s
generic/218	 14s
generic/219	 7s
generic/220	 15s
generic/221	 5s
generic/222	 14s
generic/224	 57s
generic/225	 78s
generic/226	 12s
generic/227	 15s
generic/228	 4s
generic/229	 24s
generic/230	 23s
generic/232	 17s
generic/233	 13s
generic/234	 131s
Ran: generic/216 generic/217 generic/218 generic/219 generic/220 generic/221 generic/222 generic/224 generic/225 generic/226 generic/227 generic/228 generic/229 generic/230 generic/232 generic/233 generic/234
Passed all 17 tests




To reproduce:

        # build kernel
	cd linux
	cp config-5.4.0-rc3-00002-g0d8bb3f4adaf3 .config
	make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules
	make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 INSTALL_MOD_PATH=<mod-install-dir> modules_install
	cd <mod-install-dir>
	find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz


        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> -m modules.cgz job-script # job-script is attached in this email



Thanks,
Oliver Sang