mm/z3fold.c: lock z3fold page before __SetPageMovable()
Following zsmalloc.c's example we call trylock_page() and unlock_page().
Also make z3fold_page_migrate() assert that newpage is passed in locked,
as per the documentation.
[[email protected]: fix trylock_page return value test, per Shakeel]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Henry Burns <[email protected]>
Suggested-by: Vitaly Wool <[email protected]>
Acked-by: Vitaly Wool <[email protected]>
Acked-by: David Rientjes <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Vitaly Vul <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Xidong Wang <[email protected]>
Cc: Jonathan Adams <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 985732c..dfcd69d 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -924,7 +924,16 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
set_bit(PAGE_HEADLESS, &page->private);
goto headless;
}
- __SetPageMovable(page, pool->inode->i_mapping);
+ if (can_sleep) {
+ lock_page(page);
+ __SetPageMovable(page, pool->inode->i_mapping);
+ unlock_page(page);
+ } else {
+ if (trylock_page(page)) {
+ __SetPageMovable(page, pool->inode->i_mapping);
+ unlock_page(page);
+ }
+ }
z3fold_page_lock(zhdr);
found:
@@ -1331,6 +1340,7 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(!PageIsolated(page), page);
+ VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
zhdr = page_address(page);
pool = zhdr_to_pool(zhdr);
