diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index 61d51da7e17c..50dd3d1f4d18 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1765,6 +1765,15 @@ gotten: unlock: pte_unmap_unlock(page_table, ptl); if (dirty_page) { + /* + * Yes, Virginia, this is actually required to prevent a race + * with clear_page_dirty_for_io() from clearing the page dirty + * bit after it clear all dirty ptes, but before a racing + * do_wp_page installs a dirty pte. + * + * do_no_page is protected similarly. + */ + wait_on_page_locked(dirty_page); set_page_dirty_balance(dirty_page); put_page(dirty_page); } |