diff options
| -rw-r--r-- | mm/filemap.c | 8 | ||||
| -rw-r--r-- | mm/page-writeback.c | 6 |
2 files changed, 8 insertions, 6 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 3ebbe64a0106..0b2067b3c328 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1484,11 +1484,19 @@ void end_page_writeback(struct page *page) rotate_reclaimable_page(page); } + /* + * Writeback does not hold a page reference of its own, relying + * on truncation to wait for the clearing of PG_writeback. + * But here we must make sure that the page is not freed and + * reused before the wake_up_page(). + */ + get_page(page); if (!test_clear_page_writeback(page)) BUG(); smp_mb__after_atomic(); wake_up_page(page, PG_writeback); + put_page(page); } EXPORT_SYMBOL(end_page_writeback); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 7709f0e223f5..586042472ac9 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2754,12 +2754,6 @@ int test_clear_page_writeback(struct page *page) } else { ret = TestClearPageWriteback(page); } - /* - * NOTE: Page might be free now! Writeback doesn't hold a page - * reference on its own, it relies on truncation to wait for - * the clearing of PG_writeback. The below can only access - * page state that is static across allocation cycles. - */ if (ret) { dec_lruvec_state(lruvec, NR_WRITEBACK); dec_zone_page_state(page, NR_ZONE_WRITE_PENDING); |