Re: "BUG: kernel NULL pointer dereference," when unmounting filesystem hitted by enospc error

[Johannes Thumshirn]

On 21/10/2019 11:17, Johannes Thumshirn wrote:
[...]
>> -----
>> $ cat run-btrfs-test
>> modprobe -iv zram num_devices=8
>> udevadm trigger
>> sync
>> zramctl /dev/zram0 -s 8G && \
>> zramctl /dev/zram1 -s 8G && \
>> zramctl /dev/zram2 -s 4G && \
>> zramctl /dev/zram3 -s 4G && \
>> zramctl /dev/zram4 -s 4G && \
>> zramctl /dev/zram5 -s 2G && \
>> zramctl /dev/zram6 -s 2G && \
>> zramctl /dev/zram7 -s 4G && \
>> mkfs.btrfs /dev/zram0 && \
>> mkdir -p /mnt/btrfs-test && \
>> mount /dev/zram0 /mnt/btrfs-test && \
>> echo "FS Mounted" && \
>> btrfs dev add /dev/zram1 /mnt/btrfs-test && \
>> echo "Devices added" && \
>> for int in {1..500} ; do dd if=/dev/zero of=/mnt/btrfs-test/file${int}
>> bs=32M count=1 && sync ; done
>> btrfs dev add /dev/zram[2-7] /mnt/btrfs-test && \
>> btrfs fi sh /mnt/btrfs-test && \
>> btrfs fi df /mnt/btrfs-test && \
>> btrfs bal star -mconvert=raid6 /mnt/btrfs-test && \
>> btrfs bal star -dconvert=raid6 /mnt/btrfs-test
>> btrfs fi sh /mnt/btrfs-test && \
>> btrfs fi df /mnt/btrfs-test

I'm sorry. I ran this script in a loop for 35 iterations on 5.3.6 and
couldn't reproduce a single crash.


Is there anything else needed?
-- 
Johannes Thumshirn                            SUSE Labs Filesystems
jthumsh...@suse.de                                +49 911 74053 689
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