1 files changed, 19 insertions, 10 deletions

diff --git a/mm/z3fold.c b/mm/z3fold.c
index dfcd69d08c1e..6c72b18d8b9c 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -101,6 +101,7 @@ struct z3fold_buddy_slots {
  * @refcount:           reference count for the z3fold page
  * @work:               work_struct for page layout optimization
  * @slots:              pointer to the structure holding buddy slots
+ * @pool:               pointer to the containing pool
  * @cpu:                CPU which this page "belongs" to
  * @first_chunks:       the size of the first buddy in chunks, 0 if free
  * @middle_chunks:      the size of the middle buddy in chunks, 0 if free
@@ -114,6 +115,7 @@ struct z3fold_header {
         struct kref refcount;
         struct work_struct work;
         struct z3fold_buddy_slots *slots;
+        struct z3fold_pool *pool;
         short cpu;
         unsigned short first_chunks;
         unsigned short middle_chunks;
@@ -193,8 +195,10 @@ static void compact_page_work(struct work_struct *w);
 static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool,
                                                         gfp_t gfp)
 {
-        struct z3fold_buddy_slots *slots = kmem_cache_alloc(pool->c_handle,
-                                                            gfp);
+        struct z3fold_buddy_slots *slots;
+
+        slots = kmem_cache_alloc(pool->c_handle,
+                                 (gfp & ~(__GFP_HIGHMEM | __GFP_MOVABLE)));
 
         if (slots) {
                 memset(slots->slot, 0, sizeof(slots->slot));
@@ -320,6 +324,7 @@ static struct z3fold_header *init_z3fold_page(struct page *page,
         zhdr->start_middle = 0;
         zhdr->cpu = -1;
         zhdr->slots = slots;
+        zhdr->pool = pool;
         INIT_LIST_HEAD(&zhdr->buddy);
         INIT_WORK(&zhdr->work, compact_page_work);
         return zhdr;
@@ -426,7 +431,7 @@ static enum buddy handle_to_buddy(unsigned long handle)
 
 static inline struct z3fold_pool *zhdr_to_pool(struct z3fold_header *zhdr)
 {
-        return slots_to_pool(zhdr->slots);
+        return zhdr->pool;
 }
 
 static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked)
@@ -850,7 +855,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
         enum buddy bud;
         bool can_sleep = gfpflags_allow_blocking(gfp);
 
-        if (!size || (gfp & __GFP_HIGHMEM))
+        if (!size)
                 return -EINVAL;
 
         if (size > PAGE_SIZE)
@@ -1345,24 +1350,29 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
         zhdr = page_address(page);
         pool = zhdr_to_pool(zhdr);
 
-        if (!trylock_page(page))
-                return -EAGAIN;
-
         if (!z3fold_page_trylock(zhdr)) {
-                unlock_page(page);
                 return -EAGAIN;
         }
         if (zhdr->mapped_count != 0) {
                 z3fold_page_unlock(zhdr);
-                unlock_page(page);
                 return -EBUSY;
         }
+        if (work_pending(&zhdr->work)) {
+                z3fold_page_unlock(zhdr);
+                return -EAGAIN;
+        }
         new_zhdr = page_address(newpage);
         memcpy(new_zhdr, zhdr, PAGE_SIZE);
         newpage->private = page->private;
         page->private = 0;
         z3fold_page_unlock(zhdr);
         spin_lock_init(&new_zhdr->page_lock);
+        INIT_WORK(&new_zhdr->work, compact_page_work);
+        /*
+         * z3fold_page_isolate() ensures that new_zhdr->buddy is empty,
+         * so we only have to reinitialize it.
+         */
+        INIT_LIST_HEAD(&new_zhdr->buddy);
         new_mapping = page_mapping(page);
         __ClearPageMovable(page);
         ClearPagePrivate(page);
@@ -1386,7 +1396,6 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
         queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work);
 
         page_mapcount_reset(page);
-        unlock_page(page);
         put_page(page);
         return 0;
 }