xfs: remove old vmap cache

Index: linux-2.6/fs/xfs/linux-2.6/xfs_buf.c
===================================================================
@@ -166,75 +166,6 @@ test_page_region(
 }
 
 /*
- *	Mapping of multi-page buffers into contiguous virtual space
- */
-
-typedef struct a_list {
-	void		*vm_addr;
-	struct a_list	*next;
-} a_list_t;
-
-static a_list_t		*as_free_head;
-static int		as_list_len;
-static DEFINE_SPINLOCK(as_lock);
-
-/*
- *	Try to batch vunmaps because they are costly.
- */
-STATIC void
-free_address(
-	void		*addr)
-{
-	a_list_t	*aentry;
-
-#ifdef CONFIG_XEN
-	/*
-	 * Xen needs to be able to make sure it can get an exclusive
-	 * RO mapping of pages it wants to turn into a pagetable.  If
-	 * a newly allocated page is also still being vmap()ed by xfs,
-	 * it will cause pagetable construction to fail.  This is a
-	 * quick workaround to always eagerly unmap pages so that Xen
-	 * is happy.
-	 */
-	vunmap(addr);
-	return;
-#endif
-
-	aentry = kmalloc(sizeof(a_list_t), GFP_NOWAIT);
-	if (likely(aentry)) {
-		spin_lock(&as_lock);
-		aentry->next = as_free_head;
-		aentry->vm_addr = addr;
-		as_free_head = aentry;
-		as_list_len++;
-		spin_unlock(&as_lock);
-	} else {
-		vunmap(addr);
-	}
-}
-
-STATIC void
-purge_addresses(void)
-{
-	a_list_t	*aentry, *old;
-
-	if (as_free_head == NULL)
-		return;
-
-	spin_lock(&as_lock);
-	aentry = as_free_head;
-	as_free_head = NULL;
-	as_list_len = 0;
-	spin_unlock(&as_lock);
-
-	while ((old = aentry) != NULL) {
-		vunmap(aentry->vm_addr);
-		aentry = aentry->next;
-		kfree(old);
-	}
-}
-
-/*
  *	Internal xfs_buf_t object manipulation
  */
 

@@ -333,7 +264,7 @@ xfs_buf_free(
 		uint		i;
 
 		if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1))
-			free_address(bp->b_addr - bp->b_offset);
+			vunmap(bp->b_addr - bp->b_offset);
 
 		for (i = 0; i < bp->b_page_count; i++) {
 			struct page	*page = bp->b_pages[i];

@@ -455,8 +386,6 @@ _xfs_buf_map_pages(
 		bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset;
 		bp->b_flags |= XBF_MAPPED;
 	} else if (flags & XBF_MAPPED) {
-		if (as_list_len > 64)
-			purge_addresses();
 		bp->b_addr = vmap(bp->b_pages, bp->b_page_count,
 					VM_MAP, PAGE_KERNEL);
 		if (unlikely(bp->b_addr == NULL))

@@ -1732,8 +1661,6 @@ xfsbufd(
 			count++;
 		}
 
-		if (as_list_len > 0)
-			purge_addresses();
 		if (count)
 			blk_run_address_space(target->bt_mapping);
 

Index: linux-2.6/fs/xfs/linux-2.6/xfs_buf.c
===================================================================
@@ -264,7 +264,7 @@ xfs_buf_free(
 		uint		i;
 
 		if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1))
-			vunmap(bp->b_addr - bp->b_offset);
+			vm_unmap_ram(bp->b_addr - bp->b_offset, bp->b_page_count);
 
 		for (i = 0; i < bp->b_page_count; i++) {
 			struct page	*page = bp->b_pages[i];

@@ -386,8 +386,8 @@ _xfs_buf_map_pages(
 		bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset;
 		bp->b_flags |= XBF_MAPPED;
 	} else if (flags & XBF_MAPPED) {
-		bp->b_addr = vmap(bp->b_pages, bp->b_page_count,
-					VM_MAP, PAGE_KERNEL);
+		bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count,
+					-1, PAGE_KERNEL);
 		if (unlikely(bp->b_addr == NULL))
 			return -ENOMEM;
 		bp->b_addr += bp->b_offset;

Index: linux-2.6/mm/vmalloc.c
===================================================================
@@ -509,6 +509,9 @@ static unsigned long lazy_max_pages(void
 
 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
 
+/* for per-CPU blocks */
+static void purge_fragmented_blocks_allcpus(void);
+
 /*
  * Purges all lazily-freed vmap areas.
  *

@@ -539,6 +542,9 @@ static void __purge_vmap_area_lazy(unsig
 	} else
 		spin_lock(&purge_lock);
 
+	if (sync)
+		purge_fragmented_blocks_allcpus();
+
 	rcu_read_lock();
 	list_for_each_entry_rcu(va, &vmap_area_list, list) {
 		if (va->flags & VM_LAZY_FREE) {

@@ -667,8 +673,6 @@ static bool vmap_initialized __read_most
 struct vmap_block_queue {
 	spinlock_t lock;
 	struct list_head free;
-	struct list_head dirty;
-	unsigned int nr_dirty;
 };
 
 struct vmap_block {

@@ -678,10 +682,9 @@ struct vmap_block {
 	unsigned long free, dirty;
 	DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
 	DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
-	union {
-		struct list_head free_list;
-		struct rcu_head rcu_head;
-	};
+	struct list_head free_list;
+	struct rcu_head rcu_head;
+	struct list_head purge;
 };
 
 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */

@@ -757,7 +760,7 @@ static struct vmap_block *new_vmap_block
 	vbq = &get_cpu_var(vmap_block_queue);
 	vb->vbq = vbq;
 	spin_lock(&vbq->lock);
-	list_add(&vb->free_list, &vbq->free);
+	list_add_rcu(&vb->free_list, &vbq->free);
 	spin_unlock(&vbq->lock);
 	put_cpu_var(vmap_block_queue);
 

@@ -776,8 +779,6 @@ static void free_vmap_block(struct vmap_
 	struct vmap_block *tmp;
 	unsigned long vb_idx;
 
-	BUG_ON(!list_empty(&vb->free_list));
-
 	vb_idx = addr_to_vb_idx(vb->va->va_start);
 	spin_lock(&vmap_block_tree_lock);
 	tmp = radix_tree_delete(&vmap_block_tree, vb_idx);

@@ -788,12 +789,61 @@ static void free_vmap_block(struct vmap_
 	call_rcu(&vb->rcu_head, rcu_free_vb);
 }
 
+static void purge_fragmented_blocks(int cpu)
+{
+	LIST_HEAD(purge);
+	struct vmap_block *vb;
+	struct vmap_block *n_vb;
+	struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+
+		if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
+			continue;
+
+		spin_lock(&vb->lock);
+		if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
+			vb->free = 0; /* prevent further allocs after releasing lock */
+			vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
+			bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
+			bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
+			spin_lock(&vbq->lock);
+			list_del_rcu(&vb->free_list);
+			spin_unlock(&vbq->lock);
+			spin_unlock(&vb->lock);
+			list_add_tail(&vb->purge, &purge);
+		} else
+			spin_unlock(&vb->lock);
+	}
+	rcu_read_unlock();
+
+	list_for_each_entry_safe(vb, n_vb, &purge, purge) {
+		list_del(&vb->purge);
+		free_vmap_block(vb);
+	}
+}
+
+static void purge_fragmented_blocks_thiscpu(void)
+{
+	purge_fragmented_blocks(smp_processor_id());
+}
+
+static void purge_fragmented_blocks_allcpus(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		purge_fragmented_blocks(cpu);
+}
+
 static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 {
 	struct vmap_block_queue *vbq;
 	struct vmap_block *vb;
 	unsigned long addr = 0;
 	unsigned int order;
+	int purge = 0;
 
 	BUG_ON(size & ~PAGE_MASK);
 	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);

@@ -806,24 +856,38 @@ again:
 		int i;
 
 		spin_lock(&vb->lock);
+		if (vb->free < 1UL << order)
+			goto next;
+
 		i = bitmap_find_free_region(vb->alloc_map,
 						VMAP_BBMAP_BITS, order);
 
-		if (i >= 0) {
-			addr = vb->va->va_start + (i << PAGE_SHIFT);
-			BUG_ON(addr_to_vb_idx(addr) !=
-					addr_to_vb_idx(vb->va->va_start));
-			vb->free -= 1UL << order;
-			if (vb->free == 0) {
-				spin_lock(&vbq->lock);
-				list_del_init(&vb->free_list);
-				spin_unlock(&vbq->lock);
+		if (i < 0) {
+			if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
+				/* fragmented and no outstanding allocations */
+				BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
+				purge = 1;
 			}
-			spin_unlock(&vb->lock);
-			break;
+			goto next;
 		}
+		addr = vb->va->va_start + (i << PAGE_SHIFT);
+		BUG_ON(addr_to_vb_idx(addr) !=
+				addr_to_vb_idx(vb->va->va_start));
+		vb->free -= 1UL << order;
+		if (vb->free == 0) {
+			spin_lock(&vbq->lock);
+			list_del_rcu(&vb->free_list);
+			spin_unlock(&vbq->lock);
+		}
+		spin_unlock(&vb->lock);
+		break;
+next:
 		spin_unlock(&vb->lock);
 	}
+
+	if (purge)
+		purge_fragmented_blocks_thiscpu();
+
 	put_cpu_var(vmap_block_queue);
 	rcu_read_unlock();
 

@@ -860,11 +924,11 @@ static void vb_free(const void *addr, un
 	BUG_ON(!vb);
 
 	spin_lock(&vb->lock);
-	bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order);
+	BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
 
 	vb->dirty += 1UL << order;
 	if (vb->dirty == VMAP_BBMAP_BITS) {
-		BUG_ON(vb->free || !list_empty(&vb->free_list));
+		BUG_ON(vb->free);
 		spin_unlock(&vb->lock);
 		free_vmap_block(vb);
 	} else

@@ -1033,8 +1097,6 @@ void __init vmalloc_init(void)
 		vbq = &per_cpu(vmap_block_queue, i);
 		spin_lock_init(&vbq->lock);
 		INIT_LIST_HEAD(&vbq->free);
-		INIT_LIST_HEAD(&vbq->dirty);
-		vbq->nr_dirty = 0;
 	}
 
 	/* Import existing vmlist entries. */

Index: linux-2.6/mm/vmalloc.c
===================================================================
@@ -509,6 +509,9 @@ static unsigned long lazy_max_pages(void
 
 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
 
+/* for per-CPU blocks */
+static void purge_fragmented_blocks(void);
+
 /*
  * Purges all lazily-freed vmap areas.
  *

@@ -539,6 +542,8 @@ static void __purge_vmap_area_lazy(unsig
 	} else
 		spin_lock(&purge_lock);
 
+	purge_fragmented_blocks();
+
 	rcu_read_lock();
 	list_for_each_entry_rcu(va, &vmap_area_list, list) {
 		if (va->flags & VM_LAZY_FREE) {

@@ -669,8 +674,6 @@ static bool vmap_initialized __read_most
 struct vmap_block_queue {
 	spinlock_t lock;
 	struct list_head free;
-	struct list_head dirty;
-	unsigned int nr_dirty;
 };
 
 struct vmap_block {

@@ -680,10 +683,9 @@ struct vmap_block {
 	unsigned long free, dirty;
 	DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
 	DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
-	union {
-		struct list_head free_list;
-		struct rcu_head rcu_head;
-	};
+	struct list_head free_list;
+	struct rcu_head rcu_head;
+	struct list_head purge;
 };
 
 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */

@@ -759,7 +761,7 @@ static struct vmap_block *new_vmap_block
 	vbq = &get_cpu_var(vmap_block_queue);
 	vb->vbq = vbq;
 	spin_lock(&vbq->lock);
-	list_add(&vb->free_list, &vbq->free);
+	list_add_rcu(&vb->free_list, &vbq->free);
 	spin_unlock(&vbq->lock);
 	put_cpu_var(vmap_block_queue);
 

@@ -808,23 +810,27 @@ again:
 		int i;
 
 		spin_lock(&vb->lock);
+		if (vb->free < 1UL << order)
+			goto next;
+
 		i = bitmap_find_free_region(vb->alloc_map,
 						VMAP_BBMAP_BITS, order);
 
-		if (i >= 0) {
-			addr = vb->va->va_start + (i << PAGE_SHIFT);
-			BUG_ON(addr_to_vb_idx(addr) !=
-					addr_to_vb_idx(vb->va->va_start));
-			vb->free -= 1UL << order;
-			if (vb->free == 0) {
-				spin_lock(&vbq->lock);
-				list_del_init(&vb->free_list);
-				spin_unlock(&vbq->lock);
-			}
-			spin_unlock(&vb->lock);
-			break;
+		if (i < 0)
+			goto next;
+		addr = vb->va->va_start + (i << PAGE_SHIFT);
+		BUG_ON(addr_to_vb_idx(addr) !=
+				addr_to_vb_idx(vb->va->va_start));
+		vb->free -= 1UL << order;
+		if (vb->free == 0) {
+			spin_lock(&vbq->lock);
+			list_del_rcu(&vb->free_list);
+			spin_unlock(&vbq->lock);
 		}
 		spin_unlock(&vb->lock);
+		break;
+next:
+		spin_unlock(&vb->lock);
 	}
 	put_cpu_var(vmap_block_queue);
 	rcu_read_unlock();

@@ -873,6 +879,43 @@ static void vb_free(const void *addr, un
 		spin_unlock(&vb->lock);
 }
 
+static void purge_fragmented_blocks(void)
+{
+	LIST_HEAD(purge);
+	int cpu;
+	struct vmap_block *vb;
+	struct vmap_block *n_vb;
+
+	for_each_possible_cpu(cpu) {
+		struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+
+		rcu_read_lock();
+		list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+
+			if (vb->free + vb->dirty != VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS)
+				continue;
+
+			spin_lock(&vb->lock);
+			if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
+				vb->free = 0; /* prevent further allocs after releasing lock */
+				vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
+				spin_lock(&vbq->lock);
+				list_del_rcu(&vb->free_list);
+				spin_unlock(&vbq->lock);
+				spin_unlock(&vb->lock);
+				list_add_tail(&vb->purge, &purge);
+			} else
+				spin_unlock(&vb->lock);
+		}
+		rcu_read_unlock();
+	}
+
+	list_for_each_entry_safe(vb, n_vb, &purge, purge) {
+		list_del(&vb->purge);
+		free_vmap_block(vb);
+	}
+}
+
 /**
  * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
  *

@@ -1035,8 +1078,6 @@ void __init vmalloc_init(void)
 		vbq = &per_cpu(vmap_block_queue, i);
 		spin_lock_init(&vbq->lock);
 		INIT_LIST_HEAD(&vbq->free);
-		INIT_LIST_HEAD(&vbq->dirty);
-		vbq->nr_dirty = 0;
 	}
 
 	/* Import existing vmlist entries. */