Re: [PATCH v5] generic: add a test for atomic writes

Christoph Hellwig
2025-05-05T05:37:07Z

On Fri, May 02, 2025 at 12:39:42PM -0700, Darrick J. Wong wrote:
> Me neither. We can't write 512b blocks to the rt device obviously, but
> I think the whole point of the separate "sector" size is that's the
> maximum size that the fs knows it can write to the device without
> tearing.

The sector size is really the minimum addressable unit.

> Maybe there's a way out of this: the only metadata on the realtime
> volume is the rt superblock, whose size is a full fsblock. Perhaps we
> could set/validate the block size of the rt dev with the fsblock size
> instead?

We still allow subsector dio to the rt device, so this would be a bit
of a sketchy change.