[PATCH 11/19] writeback: Use the folio_batch queue iterator

Christoph Hellwig
2024-01-25T08:58:55Z

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Instead of keeping our own local iterator variable, use the one just
added to folio_batch.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
---
mm/page-writeback.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index d6ac414ddce9ca..432bb42d0829d1 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2429,13 +2429,21 @@ static bool folio_prepare_writeback(struct address_space *mapping,
return true;
}

-static void writeback_get_batch(struct address_space *mapping,
+static struct folio *writeback_get_folio(struct address_space *mapping,
struct writeback_control *wbc)
{
- folio_batch_release(&wbc->fbatch);
- cond_resched();
- filemap_get_folios_tag(mapping, &wbc->index, wbc_end(wbc),
- wbc_to_tag(wbc), &wbc->fbatch);
+ struct folio *folio;
+
+ folio = folio_batch_next(&wbc->fbatch);
+ if (!folio) {
+ folio_batch_release(&wbc->fbatch);
+ cond_resched();
+ filemap_get_folios_tag(mapping, &wbc->index, wbc_end(wbc),
+ wbc_to_tag(wbc), &wbc->fbatch);
+ folio = folio_batch_next(&wbc->fbatch);
+ }
+
+ return folio;
}

/**
@@ -2475,7 +2483,6 @@ int write_cache_pages(struct address_space *mapping,
{
int error;
pgoff_t end; /* Inclusive */
- int i = 0;

if (wbc->range_cyclic) {
wbc->index = mapping->writeback_index; /* prev offset */
@@ -2491,18 +2498,12 @@ int write_cache_pages(struct address_space *mapping,
wbc->err = 0;

for (;;) {
- struct folio *folio;
+ struct folio *folio = writeback_get_folio(mapping, wbc);
unsigned long nr;

- if (i == wbc->fbatch.nr) {
- writeback_get_batch(mapping, wbc);
- i = 0;
- }
- if (wbc->fbatch.nr == 0)
+ if (!folio)
break;

- folio = wbc->fbatch.folios[i++];
-
folio_lock(folio);
if (!folio_prepare_writeback(mapping, wbc, folio)) {
folio_unlock(folio);
--
2.39.2