diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/migrate.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index b4979d423d2b..e9b161bde95b 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -294,7 +294,7 @@ out: static int migrate_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page) { - struct page **radix_pointer; + void **pslot; if (!mapping) { /* Anonymous page */ @@ -305,12 +305,11 @@ static int migrate_page_move_mapping(struct address_space *mapping, write_lock_irq(&mapping->tree_lock); - radix_pointer = (struct page **)radix_tree_lookup_slot( - &mapping->page_tree, - page_index(page)); + pslot = radix_tree_lookup_slot(&mapping->page_tree, + page_index(page)); if (page_count(page) != 2 + !!PagePrivate(page) || - *radix_pointer != page) { + (struct page *)radix_tree_deref_slot(pslot) != page) { write_unlock_irq(&mapping->tree_lock); return -EAGAIN; } @@ -318,7 +317,7 @@ static int migrate_page_move_mapping(struct address_space *mapping, /* * Now we know that no one else is looking at the page. */ - get_page(newpage); + get_page(newpage); /* add cache reference */ #ifdef CONFIG_SWAP if (PageSwapCache(page)) { SetPageSwapCache(newpage); @@ -326,8 +325,14 @@ static int migrate_page_move_mapping(struct address_space *mapping, } #endif - *radix_pointer = newpage; + radix_tree_replace_slot(pslot, newpage); + + /* + * Drop cache reference from old page. + * We know this isn't the last reference. + */ __put_page(page); + write_unlock_irq(&mapping->tree_lock); return 0; |