Commit 7d0795d0 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

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: default avatarMatthew 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 0410cd84

mm/filemap.c

+7 −2
Original line number Diff line number Diff line
@@ -1593,9 +1593,15 @@ EXPORT_SYMBOL(folio_wait_private_2_killable); 
/**

 * folio_end_writeback - End writeback against a folio.

 * @folio: The folio.

 *

 * The folio must actually be under writeback.

 *

 * Context: May be called from process or interrupt context.

 */

void folio_end_writeback(struct folio *folio)

{

	VM_BUG_ON_FOLIO(!folio_test_writeback(folio), folio);



	/*

	 * folio_test_clear_reclaim() could be used here but it is an

	 * atomic operation and overkill in this particular case. Failing
@@ -1615,8 +1621,7 @@ void folio_end_writeback(struct folio *folio) 
	 * reused before the folio_wake().

	 */

	folio_get(folio);

	if (!__folio_end_writeback(folio))

		BUG();

	__folio_end_writeback(folio);



	smp_mb__after_atomic();

	folio_wake(folio, PG_writeback);

mm/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ static inline void wake_throttle_isolated(pg_data_t *pgdat) 


vm_fault_t do_swap_page(struct vm_fault *vmf);

void folio_rotate_reclaimable(struct folio *folio);

bool __folio_end_writeback(struct folio *folio);

void __folio_end_writeback(struct folio *folio);

void deactivate_file_folio(struct folio *folio);

void folio_activate(struct folio *folio);

mm/page-writeback.c

+16 −22
Original line number Diff line number Diff line
@@ -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)) {
@@ -2953,8 +2952,7 @@ 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) {

		folio_test_clear_writeback(folio);

		__xa_clear_mark(&mapping->i_pages, folio_index(folio),

					PAGECACHE_TAG_WRITEBACK);

		if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
@@ -2962,11 +2960,9 @@ bool __folio_end_writeback(struct folio *folio) 


			wb_stat_mod(wb, WB_WRITEBACK, -nr);

			__wb_writeout_add(wb, nr);

				if (!mapping_tagged(mapping,

						    PAGECACHE_TAG_WRITEBACK))

			if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK))

				wb_inode_writeback_end(wb);

		}

		}



		if (mapping->host && !mapping_tagged(mapping,

						     PAGECACHE_TAG_WRITEBACK))
@@ -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);

		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_memcg_unlock(folio);

	return ret;

}



bool __folio_start_writeback(struct folio *folio, bool keep_write)