On Mon, Aug 28, 2023 at 02:32:59PM +0200, Christoph Hellwig wrote:
> On Sun, Aug 27, 2023 at 10:45:18PM +0100, Al Viro wrote:
> > IOW, I suspect that the right thing to do would be something along the lines
> > of
>
> The idea looks sensible to me, but we'll also need to do it for the
> filemap_write_and_wait_range failure case.
Huh? That's precisely where this patch is doing that... That function
in mainline is
if (unlikely(buffered_written < 0)) {
if (direct_written)
return direct_written;
return buffered_written;
}
/*
* We need to ensure that the page cache pages are written to disk and
* invalidated to preserve the expected O_DIRECT semantics.
*/
err = filemap_write_and_wait_range(mapping, pos, end);
if (err < 0) {
/*
* We don't know how much we wrote, so just return the number of
* bytes which were direct-written
*/
if (direct_written)
return direct_written;
return err;
}
invalidate_mapping_pages(mapping, pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
return direct_written + buffered_written;
The first failure exit does not need any work - the caller had not bumped
->ki_pos; the second one (after that 'if (err < 0) {' line) does and that's
where the patch upthread adds iocb->ki_pos -= buffered_written.
Or am I completely misparsing what you've written?
