Linux 5.18 Looks Like It Will Finally Land Btrfs Encoded I/O

Btrfs file-system developers remain very busy on multiple fronts from performance and reliability enhancements to in-development Btrfs on-disk format changes. A notable item now on deck for integration in Linux 5.18 is Btrfs support for encoded I/O.

Encoded I/O in this context is for being able to bypass the transparent file-system compression or encryption and read/write data directly to disk. The encoded I/O interfaces bypass the kernel's "encoding" of compression or other alterations. The encoded I/O can be used for cases where wanting to write an already-compressed file directly to disk or wanting to send/receive compressed files without uncompressing them.

The Btrfs encoded I/O support is exposed via new BTRFS_IOC_ENCODED_WRITE and BTRFC_ENCODED_READ ioctls for writing and reading in the encoded manner. Btrfs encoded I/O patches have been floating around for at least the past two years but now looks like they will be finally mainlined for Linux 5.18.

David Sterba picked up the Btrfs encoded I/O patches today into his "for-next" branch thus making it material intended to be submitted for next month's Linux 5.18 merge window unless last minute problems occur.