[PATCH 55/62] mm: Convert slob to use struct slab

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Use struct slab throughout the slob allocator.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 mm/slab.h | 15 +++++++++++++++
 mm/slob.c | 30 +++++++++++++++---------------
 2 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/mm/slab.h b/mm/slab.h
index 7631e274a840..5eabc9352bbf 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -43,6 +43,21 @@ static inline void __slab_clear_pfmemalloc(struct slab *slab)
 	__clear_bit(PG_pfmemalloc, &slab->flags);
 }
 
+static inline bool slab_test_free(const struct slab *slab)
+{
+	return test_bit(PG_slob_free, &slab->flags);
+}
+
+static inline void __slab_set_free(struct slab *slab)
+{
+	__set_bit(PG_slob_free, &slab->flags);
+}
+
+static inline void __slab_clear_free(struct slab *slab)
+{
+	__clear_bit(PG_slob_free, &slab->flags);
+}
+
 static inline void *slab_address(const struct slab *slab)
 {
 	return page_address(slab_page(slab));
diff --git a/mm/slob.c b/mm/slob.c
index 8cede39054fc..be5c9c472bbb 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -105,21 +105,21 @@ static LIST_HEAD(free_slob_large);
 /*
  * slob_page_free: true for pages on free_slob_pages list.
  */
-static inline int slob_page_free(struct page *sp)
+static inline int slob_page_free(struct slab *sp)
 {
-	return PageSlobFree(sp);
+	return slab_test_free(sp);
 }
 
-static void set_slob_page_free(struct page *sp, struct list_head *list)
+static void set_slob_page_free(struct slab *sp, struct list_head *list)
 {
 	list_add(&sp->slab_list, list);
-	__SetPageSlobFree(sp);
+	__slab_set_free(sp);
 }
 
-static inline void clear_slob_page_free(struct page *sp)
+static inline void clear_slob_page_free(struct slab *sp)
 {
 	list_del(&sp->slab_list);
-	__ClearPageSlobFree(sp);
+	__slab_clear_free(sp);
 }
 
 #define SLOB_UNIT sizeof(slob_t)
@@ -234,7 +234,7 @@ static void slob_free_pages(void *b, int order)
  *         freelist, in this case @page_removed_from_list will be set to
  *         true (set to false otherwise).
  */
-static void *slob_page_alloc(struct page *sp, size_t size, int align,
+static void *slob_page_alloc(struct slab *sp, size_t size, int align,
 			      int align_offset, bool *page_removed_from_list)
 {
 	slob_t *prev, *cur, *aligned = NULL;
@@ -301,7 +301,7 @@ static void *slob_page_alloc(struct page *sp, size_t size, int align,
 static void *slob_alloc(size_t size, gfp_t gfp, int align, int node,
 							int align_offset)
 {
-	struct page *sp;
+	struct slab *sp;
 	struct list_head *slob_list;
 	slob_t *b = NULL;
 	unsigned long flags;
@@ -323,7 +323,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node,
 		 * If there's a node specification, search for a partial
 		 * page with a matching node id in the freelist.
 		 */
-		if (node != NUMA_NO_NODE && page_to_nid(sp) != node)
+		if (node != NUMA_NO_NODE && slab_nid(sp) != node)
 			continue;
 #endif
 		/* Enough room on this page? */
@@ -358,8 +358,8 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node,
 		b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node);
 		if (!b)
 			return NULL;
-		sp = virt_to_page(b);
-		__SetPageSlab(sp);
+		sp = virt_to_slab(b);
+		__SetPageSlab(slab_page(sp));
 
 		spin_lock_irqsave(&slob_lock, flags);
 		sp->units = SLOB_UNITS(PAGE_SIZE);
@@ -381,7 +381,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node,
  */
 static void slob_free(void *block, int size)
 {
-	struct page *sp;
+	struct slab *sp;
 	slob_t *prev, *next, *b = (slob_t *)block;
 	slobidx_t units;
 	unsigned long flags;
@@ -391,7 +391,7 @@ static void slob_free(void *block, int size)
 		return;
 	BUG_ON(!size);
 
-	sp = virt_to_page(block);
+	sp = virt_to_slab(block);
 	units = SLOB_UNITS(size);
 
 	spin_lock_irqsave(&slob_lock, flags);
@@ -401,8 +401,8 @@ static void slob_free(void *block, int size)
 		if (slob_page_free(sp))
 			clear_slob_page_free(sp);
 		spin_unlock_irqrestore(&slob_lock, flags);
-		__ClearPageSlab(sp);
-		page_mapcount_reset(sp);
+		__ClearPageSlab(slab_page(sp));
+		page_mapcount_reset(slab_page(sp));
 		slob_free_pages(b, 0);
 		return;
 	}
-- 
2.32.0