[PATCH] mm: rmap with inner ptlock
rmap's page_check_address descend without page_table_lock. First just
pte_offset_map in case there's no pte present worth locking for, then take
page_table_lock for the full check, and pass ptl back to caller in the same
style as pte_offset_map_lock. __xip_unmap, page_referenced_one and
try_to_unmap_one use pte_unmap_unlock. try_to_unmap_cluster also.
page_check_address reformatted to avoid progressive indentation. No use is
made of its one error code, return NULL when it fails.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index e80fb7ee..35b30e6 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -95,8 +95,8 @@
/*
* Called from mm/filemap_xip.c to unmap empty zero page
*/
-pte_t *page_check_address(struct page *, struct mm_struct *, unsigned long);
-
+pte_t *page_check_address(struct page *, struct mm_struct *,
+ unsigned long, spinlock_t **);
/*
* Used by swapoff to help locate where page is expected in vma.