Re: [RFC PATCH] fpathconf() for fsync() behavior

Theodore Tso
2009-04-23T14:11:25Z

On Thu, Apr 23, 2009 at 08:48:01AM -0400, Jeff Garzik wrote:
> Theodore Tso wrote:
>> So we can create a more finer-grained controlled system call ---
>> although I would suggest that we just add some extra flags to
>> sync_file_range() --- but it's doubtful that many application
>> programmers will use it.
>
> sync_file_range() seems the obvious avenue for new fsync flags.
>
> I even explored what it would take to add a "flush storage dev writeback
> cache, for this file" flag to sync_file_range(), rather unfortunately
> non-trivial given the current implementation's close ties to MM.

What I had roughly in mind was some (optional) calls to the filesystem
before and after the current implementations MM magic, but I haven't
thought very deeply on the subject yet, mainly because...

> But yeah... how many people will use these fancy new flags and features?
>

Yeah. That issue.

It would be nice to have some additional semantics, but in terms of
priorities, it's not the highest thing on my list in terms of itches
to scratch.

- Ted