On Thu, Apr 25, 2024 at 09:10:16PM +0100, Matthew Wilcox wrote: > On Thu, Apr 25, 2024 at 01:37:40PM +0200, Pankaj Raghav (Samsung) wrote: > > From: Pankaj Raghav <p.raghav@xxxxxxxxxxx> > > > > Splitting a larger folio with a base order is supported using > > split_huge_page_to_list_to_order() API. However, using that API for LBS > > is resulting in an NULL ptr dereference error in the writeback path [1]. > > > > Refuse to split a folio if it has minimum folio order requirement until > > we can start using split_huge_page_to_list_to_order() API. Splitting the > > folio can be added as a later optimization. > > > > [1] https://gist.github.com/mcgrof/d12f586ec6ebe32b2472b5d634c397df > > Obviously this has to be tracked down and fixed before this patchset can > be merged ... I think I have some ideas. Let me look a bit. How > would I go about reproducing this? Using kdevops this is easy: make defconfig-lbs-xfs-small -j $(nproc) make -j $(nproc) make fstests make linux make fstests-baseline TESTS=generic/447 COUNT=10 tail -f guestfs/*-xfs-reflink-16k-4ks/console.log or sudo virsh list sudo virsh console ${foo}-xfs-reflink-16k-4ks Where $foo is the value of CONFIG_KDEVOPS_HOSTS_PREFIX in .config for your kdevops run. Otherwise if you wanna run things manually the above uses an lbs branch called large-block-minorder on kdevops [0] based on v6.9-rc5 with: a) Fixes we know we need b) this patch series minus this patch c) A truncation enablement patch Note that the above also uses an fstests git tree with the fstests changes we also have posted as fixes and some new tests which have been posted [1]. You will then want to run: ./check -s xfs_reflink_16k_4ks -I 10 generic/447 The configuration for xfs_reflink_16k_4ks follows: cat /var/lib/xfstests/configs/min-xfs-reflink-16k-4ks.config [default] FSTYP=xfs TEST_DIR=/media/test SCRATCH_MNT=/media/scratch RESULT_BASE=$PWD/results/$HOST/$(uname -r) DUMP_CORRUPT_FS=1 CANON_DEVS=yes RECREATE_TEST_DEV=true SOAK_DURATION=9900 [xfs_reflink_16k_4ks] TEST_DEV=/dev/loop16 SCRATCH_DEV_POOL="/dev/loop5 /dev/loop6 /dev/loop7 /dev/loop8 /dev/loop9 /dev/loop10 /dev/loop11 /dev/loop12" MKFS_OPTIONS='-f -m reflink=1,rmapbt=1, -i sparse=1, -b size=16384, -s size=4k' USE_EXTERNAL=no LOGWRITES_DEV=/dev/loop15 I didn't have time to verify if the above commands for kdevops worked but... in theory its possible it may, because you know, May is right around the corner, and May... the force be with us. [0] https://github.com/linux-kdevops/linux/tree/large-block-minorder [1] https://github.com/linux-kdevops/fstests Luis
