Commit 7fce207a authored by Joanne Koong's avatar Joanne Koong Committed by Miklos Szeredi
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mm/writeback: add folio_mark_dirty_lock() 



Add a new convenience helper folio_mark_dirty_lock() that grabs the
folio lock before calling folio_mark_dirty().

Refactor set_page_dirty_lock() to directly use folio_mark_dirty_lock().

Signed-off-by: default avatarJoanne Koong <joannelkoong@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent cbe9c115

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -2539,6 +2539,7 @@ struct kvec; 
struct page *get_dump_page(unsigned long addr);



bool folio_mark_dirty(struct folio *folio);

bool folio_mark_dirty_lock(struct folio *folio);

bool set_page_dirty(struct page *page);

int set_page_dirty_lock(struct page *page);

mm/folio-compat.c

+6 −0
Original line number Diff line number Diff line
@@ -52,6 +52,12 @@ bool set_page_dirty(struct page *page) 
}

EXPORT_SYMBOL(set_page_dirty);



int set_page_dirty_lock(struct page *page)

{

	return folio_mark_dirty_lock(page_folio(page));

}

EXPORT_SYMBOL(set_page_dirty_lock);



bool clear_page_dirty_for_io(struct page *page)

{

	return folio_clear_dirty_for_io(page_folio(page));

mm/page-writeback.c

+11 −11
Original line number Diff line number Diff line
@@ -2914,25 +2914,25 @@ bool folio_mark_dirty(struct folio *folio) 
EXPORT_SYMBOL(folio_mark_dirty);



/*

 * set_page_dirty() is racy if the caller has no reference against

 * page->mapping->host, and if the page is unlocked.  This is because another

 * CPU could truncate the page off the mapping and then free the mapping.

 * folio_mark_dirty() is racy if the caller has no reference against

 * folio->mapping->host, and if the folio is unlocked.  This is because another

 * CPU could truncate the folio off the mapping and then free the mapping.

 *

 * Usually, the page _is_ locked, or the caller is a user-space process which

 * Usually, the folio _is_ locked, or the caller is a user-space process which

 * holds a reference on the inode by having an open file.

 *

 * In other cases, the page should be locked before running set_page_dirty().

 * In other cases, the folio should be locked before running folio_mark_dirty().

 */

int set_page_dirty_lock(struct page *page)

bool folio_mark_dirty_lock(struct folio *folio)

{

	int ret;

	bool ret;



	lock_page(page);

	ret = set_page_dirty(page);

	unlock_page(page);

	folio_lock(folio);

	ret = folio_mark_dirty(folio);

	folio_unlock(folio);

	return ret;

}

EXPORT_SYMBOL(set_page_dirty_lock);

EXPORT_SYMBOL(folio_mark_dirty_lock);



/*

 * This cancels just the dirty bit on the kernel page itself, it does NOT