Commit 46afff45 authored by Kairui Song's avatar Kairui Song Committed by Andrew Morton
Browse files

mm/page-writeback: drop usage of folio_index 

folio_index is only needed for mixed usage of page cache and swap cache. 
The remaining three caller in page-writeback are for page cache tag
marking.  Swap cache space doesn't use tag (explicitly sets
mapping_set_no_writeback_tags), so use folio->index here directly.

Link: https://lkml.kernel.org/r/20250825163721.17734-1-ryncsn@gmail.com


Signed-off-by: default avatarKairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 79dfed09

mm/page-writeback.c

+11 −5
Original line number Diff line number Diff line
@@ -38,10 +38,10 @@ 
#include <linux/sched/rt.h>

#include <linux/sched/signal.h>

#include <linux/mm_inline.h>

#include <linux/shmem_fs.h>

#include <trace/events/writeback.h>



#include "internal.h"

#include "swap.h"



/*

 * Sleep at most 200ms at a time in balance_dirty_pages().
@@ -2705,11 +2705,17 @@ void __folio_mark_dirty(struct folio *folio, struct address_space *mapping, 
{

	unsigned long flags;



	/*

	 * Shmem writeback relies on swap, and swap writeback is LRU based,

	 * not using the dirty mark.

	 */

	VM_WARN_ON_ONCE(folio_test_swapcache(folio) || shmem_mapping(mapping));



	xa_lock_irqsave(&mapping->i_pages, flags);

	if (folio->mapping) {	/* Race with truncate? */

		WARN_ON_ONCE(warn && !folio_test_uptodate(folio));

		folio_account_dirtied(folio, mapping);

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

		__xa_set_mark(&mapping->i_pages, folio->index,

			      PAGECACHE_TAG_DIRTY);

	}

	xa_unlock_irqrestore(&mapping->i_pages, flags);
@@ -2989,7 +2995,7 @@ bool __folio_end_writeback(struct folio *folio) 


		xa_lock_irqsave(&mapping->i_pages, flags);

		ret = folio_xor_flags_has_waiters(folio, 1 << PG_writeback);

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

		__xa_clear_mark(&mapping->i_pages, folio->index,

					PAGECACHE_TAG_WRITEBACK);

		if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {

			struct bdi_writeback *wb = inode_to_wb(inode);
@@ -3026,7 +3032,7 @@ void __folio_start_writeback(struct folio *folio, bool keep_write) 
	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);



	if (mapping && mapping_use_writeback_tags(mapping)) {

		XA_STATE(xas, &mapping->i_pages, folio_index(folio));

		XA_STATE(xas, &mapping->i_pages, folio->index);

		struct inode *inode = mapping->host;

		struct backing_dev_info *bdi = inode_to_bdi(inode);

		unsigned long flags;