Linux 4.14.2 Fixes The BCache Corruption Bug

Normally I don't bother mentioning new Linux kernel point releases on Phoronix unless there are some significant changes, as is the case today with Linux 4.14.2.

The Linux 4.14.2 kernel release is notable if you are using the BCache block layer cache as there are known cases of Linux 4.14 causing data corruption. That issue has been resolved with Linux 4.14.2. There's also the possibility of other data corruption within other areas of the block subsystem with the 4.14.0/4.14.1 kernel, but when using BCache is the most common corruption case.

For those not familiar with BCache, it's a means of pairing a larger capacity HDD with a smaller but faster SSD to serve as a read/write cache for Linux. Growing out of BCache as well has been the separate BCachefs file-system effort that is yet to be mainlined.

Details on that corruption problem are outlined in this Gentoo bug report and elsewhere. With Linux 4.14.2 changes is the bio: ensure __bio_clone_fast copies bi_partno patch due to new fields being introduced and being updated for the disk information not partition information "At minimum, this regressed bcache and caused data corruption."

Linux 4.14.2 can be grabbed from the usual sources.