Re: [RFC PATCH] fat: add noflush mount option

[David Timber <dxdt@dev.snart.me>]

On 8/26/26 16:21, OGAWA Hirofumi wrote:
> David Timber <dxdt@dev.snart.me> writes:
>
>> On 8/25/26 13:31, OGAWA Hirofumi wrote:
>>> Well, with a your patch, just remounting without "flush" option doesn't
>>> remove flush?
>> fat_parse_param() doesn't behave like other fs. The current
>> implementation only accepts rw and ro for reconfig. So the option cannot
>> be flipped up and down at will.
> I meant with your patch. With your patch, it updates flush to current
> option set, right? And default flush=false, I may missing something
> though.
Of course. It shouldn't change the default behaviour. When mounting, if
"flush" is in the mount options, it must be honored UNLESS "noflush" is
also specified later in the sequences. If neither "flush" or "noflush"
is specified, then it's not set at all. Specifying "noflush" only should
be no-op.

If the patch doesn't behave like that, that'd be my mistake and should
be fixed.

When doing "mount -o remount,..." the patch changes the existing
behaviour so that "flush" and "noflush" are now honored. Regardless of
the previous sbi config, for "-o remount,flush" -> it always sets flush.
For "-o remount,noflush" -> always clear flush.

Hope that cleared things up.