Re: [PATCH 01/21] block: Add atomic write operations to request_queue limits

Bart Van Assche
2023-10-04T21:01:04Z

On 10/3/23 20:00, Martin K. Petersen wrote:
>
> Bart,
>
>> also that there are no guarantees that the data written by an atomic
>> write will survive a power failure. See also the difference between
>> the NVMe parameters AWUN and AWUPF.
>
> We only care about *PF. The *N variants were cut from the same cloth as
> TRIM and UNMAP.

Hi Martin,

Has the following approach been considered? RWF_ATOMIC only guarantees
atomicity. Persistence is not guaranteed without fsync() / fdatasync().

I think this would be more friendly towards battery-powered devices
(smartphones). On these devices it can be safe to skip fsync() /
fdatasync() if the battery level is high enough.

Thanks,

Bart.