mm: make __end_folio_writeback() return void

Rather than check the result of test-and-clear, just check that we have
the writeback bit set at the start.  This wouldn't catch every case, but
it's good enough (and enables the next patch).

Link: https://lkml.kernel.org/r/20231004165317.1061855-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 16 insertions, 22 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 001adbb4a180..a37e4c33d1ab 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2940,11 +2940,10 @@ static void wb_inode_writeback_end(struct bdi_writeback *wb)
 	spin_unlock_irqrestore(&wb->work_lock, flags);
 }
 
-bool __folio_end_writeback(struct folio *folio)
+void __folio_end_writeback(struct folio *folio)
 {
 	long nr = folio_nr_pages(folio);
 	struct address_space *mapping = folio_mapping(folio);
-	bool ret;
 
 	folio_memcg_lock(folio);
 	if (mapping && mapping_use_writeback_tags(mapping)) {
@@ -2953,19 +2952,16 @@ bool __folio_end_writeback(struct folio *folio)
 		unsigned long flags;
 
 		xa_lock_irqsave(&mapping->i_pages, flags);
-		ret = folio_test_clear_writeback(folio);
-		if (ret) {
-			__xa_clear_mark(&mapping->i_pages, folio_index(folio),
-						PAGECACHE_TAG_WRITEBACK);
-			if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
-				struct bdi_writeback *wb = inode_to_wb(inode);
-
-				wb_stat_mod(wb, WB_WRITEBACK, -nr);
-				__wb_writeout_add(wb, nr);
-				if (!mapping_tagged(mapping,
-						    PAGECACHE_TAG_WRITEBACK))
-					wb_inode_writeback_end(wb);
-			}
+		folio_test_clear_writeback(folio);
+		__xa_clear_mark(&mapping->i_pages, folio_index(folio),
+					PAGECACHE_TAG_WRITEBACK);
+		if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
+			struct bdi_writeback *wb = inode_to_wb(inode);
+
+			wb_stat_mod(wb, WB_WRITEBACK, -nr);
+			__wb_writeout_add(wb, nr);
+			if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK))
+				wb_inode_writeback_end(wb);
 		}
 
 		if (mapping->host && !mapping_tagged(mapping,
@@ -2974,15 +2970,13 @@ bool __folio_end_writeback(struct folio *folio)
 
 		xa_unlock_irqrestore(&mapping->i_pages, flags);
 	} else {
-		ret = folio_test_clear_writeback(folio);
-	}
-	if (ret) {
-		lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr);
-		zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
-		node_stat_mod_folio(folio, NR_WRITTEN, nr);
+		folio_test_clear_writeback(folio);
 	}
+
+	lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr);
+	zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
+	node_stat_mod_folio(folio, NR_WRITTEN, nr);
 	folio_memcg_unlock(folio);
-	return ret;
 }
 
 bool __folio_start_writeback(struct folio *folio, bool keep_write)