xfs: refactor the tail of xfs_writepage_map

Rejuggle how we deal with the different error vs non-error and have
ioends vs not have ioend cases to keep the fast path streamlined, and
the duplicate code at a minimum.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2018-07-11 22:26:04 -07:00 committed by Darrick J. Wong
parent 1b65d3dd2d
commit 8e1f065bea

View file

@ -854,7 +854,14 @@ xfs_writepage_map(
* submission of outstanding ioends on the writepage context so they are
* treated correctly on error.
*/
if (count) {
if (unlikely(error)) {
if (!count) {
xfs_aops_discard_page(page);
ClearPageUptodate(page);
unlock_page(page);
goto done;
}
/*
* If the page was not fully cleaned, we need to ensure that the
* higher layers come back to it correctly. That means we need
@ -863,43 +870,35 @@ xfs_writepage_map(
* so another attempt to write this page in this writeback sweep
* will be made.
*/
if (error) {
set_page_writeback_keepwrite(page);
} else {
clear_page_dirty_for_io(page);
set_page_writeback(page);
}
unlock_page(page);
/*
* Preserve the original error if there was one, otherwise catch
* submission errors here and propagate into subsequent ioend
* submissions.
*/
list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
int error2;
list_del_init(&ioend->io_list);
error2 = xfs_submit_ioend(wbc, ioend, error);
if (error2 && !error)
error = error2;
}
} else if (error) {
xfs_aops_discard_page(page);
ClearPageUptodate(page);
unlock_page(page);
set_page_writeback_keepwrite(page);
} else {
/*
* We can end up here with no error and nothing to write if we
* race with a partial page truncate on a sub-page block sized
* filesystem. In that case we need to mark the page clean.
*/
clear_page_dirty_for_io(page);
set_page_writeback(page);
unlock_page(page);
end_page_writeback(page);
}
unlock_page(page);
/*
* Preserve the original error if there was one, otherwise catch
* submission errors here and propagate into subsequent ioend
* submissions.
*/
list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
int error2;
list_del_init(&ioend->io_list);
error2 = xfs_submit_ioend(wbc, ioend, error);
if (error2 && !error)
error = error2;
}
/*
* We can end up here with no error and nothing to write if we race with
* a partial page truncate on a sub-page block sized filesystem.
*/
if (!count)
end_page_writeback(page);
done:
mapping_set_error(page->mapping, error);
return error;
}