Hi list, I'm getting the following log while trying to mount my filesystem: [ 23.403026] BTRFS: device label dstore devid 1 transid 1288839 /dev/dm-8 [ 23.491459] BTRFS info (device dm-8): enabling auto defrag [ 23.491461] BTRFS info (device dm-8): disk space caching is enabled [ 23.717506] BTRFS info (device dm-8): bdev /dev/mapper/vg- dstore errs: wr 0, rd 728, flush 0, corrupt 16, gen 0 [ 32.108724] BTRFS error (device dm-8): bad tree block start, want 39854304329728 have 0 [ 32.110570] BTRFS error (device dm-8): bad tree block start, want 39854304329728 have 0 [ 32.112030] BTRFS error (device dm-8): failed to read block groups: -5 [ 32.273712] BTRFS error (device dm-8): open_ctree failed A check gives me: #btrfs check /dev/mapper/recovery Opening filesystem to check... checksum verify failed on 39854304329728 found E4E3BDB6 wanted 00000000 checksum verify failed on 39854304329728 found E4E3BDB6 wanted 00000000 checksum verify failed on 39854304329728 found E4E3BDB6 wanted 00000000 checksum verify failed on 39854304329728 found E4E3BDB6 wanted 00000000 bad tree block 39854304329728, bytenr mismatch, want=39854304329728, have=0 ERROR: cannot open file system The same thing happens with the other superblocks, all superblocks are not corrupted. The reason this happened is a controller failure occurred while trying to expand the underlying raid6 causing some pretty nasty drive dropouts. Looking through older generations of tree roots, I'm getting the same zeroed node at 39854304329728. It seems like at some point md messed up recovering from the controller failure (or rather I did) and it seems like I am getting a lot of zeroed-out/corrupted areas? Can someone confirm if that is the case or if it is just some weird state the filesystem is in? I'm not hung up about hosing the filesystem as we have a complete backup before doing the raid expansion, but it'd be great if I can avoid restoring as that will take a very long time. Other obligatory information: # uname -a Linux dstore-1 4.19.0-4-amd64 #1 SMP Debian 4.19.28-2 (2019-03-15) x86_64 GNU/Linux # btrfs --version btrfs-progs v4.20.1 Thank you very much! Liwei
