Performing verification for Bionic. I installed 4.15.0-151-generic from -updates, and added the reproducer btrfs qcow2 image file to my VM.
From there, I mounted the filesystem and attempted to balance: $ sudo mount /dev/vdb /mnt $ sudo btrfs filesystem balance start --full-balance /mnt Segmentation fault (core dumped) Checking dmesg, we get the same oops as I reported: https://paste.ubuntu.com/p/wWHCgzZxTZ/ I then enabled -proposed and installed 4.15.0-152-generic, and rebooted: $ sudo mount /dev/vdb /mnt $ sudo btrfs filesystem balance start --full-balance /mnt ERROR: error during balancing '/mnt': No space left on device $ dmesg | tail -n 7 [ 34.131066] BTRFS info (device vdb): disk space caching is enabled [ 34.131070] BTRFS info (device vdb): has skinny extents [ 34.149906] BTRFS info (device vdb): checking UUID tree [ 34.149946] BTRFS info (device vdb): continuing balance [ 34.227645] BTRFS info (device vdb): 2 enospc errors during balance [ 40.009032] BTRFS info (device vdb): relocating block group 27995340800 flags data [ 40.200573] BTRFS info (device vdb): 14 enospc errors during balance We no longer suffer a kernel oops, and instead, we correctly report that the disk is too full and a balance cannot be completed. After deleting some files and re-issuing balances, balancing completes successfully. $ sudo btrfs filesystem df /mnt Data, single: total=4.88GiB, used=4.51GiB System, DUP: total=32.00MiB, used=16.00KiB Metadata, DUP: total=256.00MiB, used=5.39MiB GlobalReserve, single: total=16.00MiB, used=0.00B $ sudo btrfs filesystem balance start --full-balance /mnt Done, had to relocate 8 out of 8 chunks The kernel in -proposed fixes the problem, happy to mark Bionic as verified. ** Tags removed: verification-needed-bionic ** Tags added: verification-done-bionic -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1933172 Title: btrfs: Attempting to balance a nearly full filesystem with relocated root nodes fails To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1933172/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
