Merge tag 'kvm-ppc-next-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulu...

[linux.git] / mm / migrate.c

diff --git a/mm/migrate.c b/mm/migrate.c
index a16b15090df3b5f62e8421b16d642db113075eeb..d4fd680be3b0facd6ca1730612b74372a77a196a 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -709,7 +709,6 @@ static bool buffer_migrate_lock_buffers(struct buffer_head *head,
        /* Simple case, sync compaction */
        if (mode != MIGRATE_ASYNC) {
                do {
-                       get_bh(bh);
                        lock_buffer(bh);
                        bh = bh->b_this_page;
 
@@ -720,18 +719,15 @@ static bool buffer_migrate_lock_buffers(struct buffer_head *head,
 
        /* async case, we cannot block on lock_buffer so use trylock_buffer */
        do {
-               get_bh(bh);
                if (!trylock_buffer(bh)) {
                        /*
                         * We failed to lock the buffer and cannot stall in
                         * async migration. Release the taken locks
                         */
                        struct buffer_head *failed_bh = bh;
-                       put_bh(failed_bh);
                        bh = head;
                        while (bh != failed_bh) {
                                unlock_buffer(bh);
-                               put_bh(bh);
                                bh = bh->b_this_page;
                        }
                        return false;
@@ -818,7 +814,6 @@ static int __buffer_migrate_page(struct address_space *mapping,
        bh = head;
        do {
                unlock_buffer(bh);
-               put_bh(bh);
                bh = bh->b_this_page;
 
        } while (bh != head);
@@ -1135,10 +1130,13 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
         * If migration is successful, decrease refcount of the newpage
         * which will not free the page because new page owner increased
         * refcounter. As well, if it is LRU page, add the page to LRU
-        * list in here.
+        * list in here. Use the old state of the isolated source page to
+        * determine if we migrated a LRU page. newpage was already unlocked
+        * and possibly modified by its owner - don't rely on the page
+        * state.
         */
        if (rc == MIGRATEPAGE_SUCCESS) {
-               if (unlikely(__PageMovable(newpage)))
+               if (unlikely(!is_lru))
                        put_page(newpage);
                else
                        putback_lru_page(newpage);