Reiser4 Patch Released For Linux 4.20 Kernel Support Plus A Few Fixes

While a few days ago I wrote about the Reiser4 port to the Linux 4.20 kernel being a work-in-progress, now it's officially been released with their first tagged patch release since Linux 4.18.

Most often the Reiser4 patch releases for new Linux kernels is just that: simply getting this once promising file-system working on the mainline Linux kernel source tree. With the reiser4-for-4.20.0.patch, this time around it also adds a couple new fixes:

- Unlock page in error path of write_begin_cryptcompress(). This fixes up a deadlock reproducible in latest kernels (e.g. with stress.sh -n 20).

- Remove unneeded calls of znode_make_dirty() which are leaks of reserved disk space in scan_ctail() and pre_convert_ctail() reported by Pierre-Philipp Braun.

- Keep a track of read-only state in reiser4 context. Added a new bit field .ro in reiser4 context to indicate that execution started in read-only file system, so that disk space wasn't grabbed, and we don't need to update file's atime in that context. This prevents an oops at boot time for a system with root over reiser4 partition reported by Pierre-Philipp Braun.

With Reiser4 not a candidate for mainlining at least for now, those wanting to try out the file-system will need to grab the patch from SourceForge.