On Mon, Jan 17, 2022 at 01:30:05PM +0000, Matthew Wilcox wrote: > I think for DIO, you're sacrificing the entire buffer with any filesystem. > If the underlying file is split across multiple drives, or is even > just fragmented on a single drive, we'll submit multiple BIOs which > will complete independently (even for SCSI which writes sequentially; > never mind NVMe which can DMA blocks asynchronously). It might be > more apparent in a networking situation where errors are more common, > but it's always been a possibility since Linux introduced DIO. Yes. Probably because of that we also never allow short reads or writes due to I/O errrors but always fail the whole I/O.
