Re: [PATCH v4 6/9] f2fs: don't allow DIO reads but not DIO writes

Christoph Hellwig
2022-08-21T08:53:42Z

On Mon, Aug 15, 2022 at 05:55:45PM -0700, Eric Biggers wrote:
> So if the zoned device feature becomes widely adopted, then STATX_DIOALIGN will
> be useless on all Android devices? That sounds undesirable. Are you sure that

We just need to fix f2fs to support direct I/O on zone devices. There
is not good reason not to support it, in fact the way how zoned devices
requires appends with the Zone Append semantics makes direct I/O way
safer than how f2fs does direct I/O currently on non-zoned devices.

Until then just supporting direct I/O reads on zoned devices for f2fs
seems like a really bad choice given that it will lead to nasty cache
incoherency.