Memory Management Summit News Today

The bcachefs filesystem has been under development for a number of years now; according to lead developer Kent Overstreet, it is time to start talking about getting the code upstream. He came to the 2018 Linux Storage, Filesystem, and Memory-Management Summit (LSFMM) to discuss that in a combined filesystem and storage session. Bcachefs grew out of bcache, which is a block layer cache that was merged into Linux 3.10 in mid-2013.

In a filesystem track session at the 2018 Linux Storage, Filesystem, and Memory-Management Summit (LSFMM), Darrick Wong talked about the online scrubbing and repair features he has been working on. His target has mostly been XFS, but he has concurrently been working on scrubbing for ext4. Part of what he wanted to discuss was the possibility of standardizing some of these interfaces across different filesystem types.

When kernel code needs to work directly with user-space pages, it often calls get_user_pages() (or one of several variants) to fault those pages into RAM and pin them there. This function is not entirely easy to use, though, and recent changes have made it harder to use safely. Jan Kara and Dan Williams led a plenary session at the 2018 Linux Storage, Filesystem, and Memory-Management Summit to discuss potential solutions, but it is not entirely clear that any were found.