This happens on kernel versions 4.19.76-4.19.79 on x86_64 (Slackware): With support for btrfs, f2fs, ext*, xfs and a few others compiled in kernel it panics when accessing a btrfs root device. If support for f2fs is removed all works normally on 4.19.79, as does versions before 4.19.76. The problem has been verified on different machines by different users.
Related linuxquestions.org thread: https://www.linuxquestions.org/questions/slackware-14/the-latest-kernel-release-4175597503/page112.html
The issue is present in 4.14 longterm, 4.19 longterm and 5.2 stable EOL. The cause is the following patch: July 2: Original commit 10f966bbf521bb9b2e497bbca496a5141f4071d0 f2fs: use generic EFSBADCRC/EFSCORRUPTED July 12: Merged into mainline with f2fs-for-5.3 July 28: Fix from Icenowy Zheng (read this for some background) 38fb6d0ea34299d97b031ed64fe994158b6f8eb3 f2fs: use EINVAL for superblock with invalid magic July 30: Fix merged into mainline with f2fs-for-5.4-rc3 (note the typo in branch name, this was actually for 5.3-rc3) September 15: Kernel 5.3 was born so already contained the fix. It was backported into the relevant branches below: October 1: Original commit merged into 5.2.18 5.2.18 (5.2.19, 5.2.20, 5.2.21 EOL still affected) c704eb3aaffae0d6463b1773b37e69695b112ca4 f2fs: use generic EFSBADCRC/EFSCORRUPTED October 1: Original commit merged into 4.19.76 4.19.76 (4.19.77, 4.19.78, 4.19.79 still affected) 59a5cea41dd0ae706ab83f8ecd64199aadefb493 f2fs: use generic EFSBADCRC/EFSCORRUPTED October 5: Original commit merged into 4.14.147 4.14.147 (4.14.148 and 4.14.149 still affected) e991f02f6f9117514ed1374b39ce195013ab9cd0 f2fs: use generic EFSBADCRC/EFSCORRUPTED ... Further notes: * To date, 4.14, 4.19 and 5.2 all contain the issue. * The f2fs development/stable kernel branches contain a fix (including their 4.14 and 4.19 branches), so the issue is not present there. * Not quite sure why this commit was backported at all to longterm, but maybe I am missing some behavioural change which warranted it. (To me, it seems like this was long-standing functionality already).
Thanks for the reply. This is a real mess for Slackware since we use "huge" kernels with support for nearly every file system as default installation kernels. This particular flavour often remain as system default as it gets upgraded. This is how it was discovered, when someone upgraded his server with a btrfs root fs and a "huge" kernel.
Thanks for the quick response 4.19.80 works just fine here :)
Confirmed that 4.19.80 is fine also. Sorry for the delayed reply.