2022-04-22 18:54:16

by Jaegeuk Kim

[permalink] [raw]
Subject: Re: [PATCH] f2fs: use flush command instead of FUA for zoned device

On 04/19, Christoph Hellwig wrote:
> On Tue, Apr 19, 2022 at 02:57:03PM -0700, Jaegeuk Kim wrote:
> > The block layer for zoned disk can reorder the FUA'ed IOs. Let's use flush
> > command to keep the write order.
>
> The block layer can reorder all commands. Given that FUA only affects
> the command itself that should not matter. What is this trying to fix?

Not for zoned disk, as I mentioned. The mq-deadline serializes write commands
but I got an reordered command, if there's a FUA|PREFLUSH command, which emits
EIO by the disk.