What about other filesystems?

Posted Jan 18, 2021 5:34 UTC (Mon) by joib (subscriber, #8541)
In reply to: What about other filesystems? by NYKevin
Parent article: Fast commits for ext4

I believe io_uring supports fsync, so that would be a way to do an asynchronous fsync on somewhat modern Linux.

What about other filesystems?

Posted Jan 18, 2021 7:16 UTC (Mon) by NYKevin (subscriber, #129325) [Link]

Well, you can also use aio_fsync(3), but that's basically just a crappier version of "use a thread pool."

IMHO this is a broader issue with aio(7) and not a problem with fsync in particular.

What about other filesystems?

Posted Jan 18, 2021 10:45 UTC (Mon) by farnz (subscriber, #17727) [Link]

io_uring does provide the primitives needed; there's IORING_OP_FSYNC (with IORING_FSYNC_DATASYNC to weaken from fsync to fdatasync) and IORING_OP_SYNC_FILE_RANGE for flushing caches asynchronously, and the IOSQE_IO_DRAIN and IOSQE_IO_LINK flags to order io_uring operations with respect to each other so that you can issue the fsync after all the related writes have been done.