While it didn't make it as part of the initial staging pull for the Linux 3.12 merge window
, on Sunday dm-writeboost was proposed for staging. DM-Writeboost is new log-structured Linux caching software.
DM-Writeboost batches incoming random writes so that when writing to a cache device it will write out as a large sequential write. There's already DM-Cache and Bcache for the Linux kernel but DM-Writeboost focuses on "bursty writes" and for maximizing the life of solid-state drives (SSDs) by using sequential writes.
More details on DM-Writeboost can be found via the Linux kernel mailing list post
and its attached 3,600 lines of new code for the Linux kernel.