1 files changed, 50 insertions, 30 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 9bb6610f499b..33e245ebe70c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -331,6 +331,7 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
 
 
 static DEFINE_SPINLOCK(vmap_area_lock);
+static DEFINE_SPINLOCK(free_vmap_area_lock);
 /* Export for kexec only */
 LIST_HEAD(vmap_area_list);
 static LLIST_HEAD(vmap_purge_list);
@@ -1114,7 +1115,7 @@ retry:
 		 */
 		pva = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
 
-	spin_lock(&vmap_area_lock);
+	spin_lock(&free_vmap_area_lock);
 
 	if (pva && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, pva))
 		kmem_cache_free(vmap_area_cachep, pva);
@@ -1124,14 +1125,17 @@ retry:
 	 * returned. Therefore trigger the overflow path.
 	 */
 	addr = __alloc_vmap_area(size, align, vstart, vend);
+	spin_unlock(&free_vmap_area_lock);
+
 	if (unlikely(addr == vend))
 		goto overflow;
 
 	va->va_start = addr;
 	va->va_end = addr + size;
 	va->vm = NULL;
-	insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
 
+	spin_lock(&vmap_area_lock);
+	insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
 	spin_unlock(&vmap_area_lock);
 
 	BUG_ON(!IS_ALIGNED(va->va_start, align));
@@ -1141,7 +1145,6 @@ retry:
 	return va;
 
 overflow:
-	spin_unlock(&vmap_area_lock);
 	if (!purged) {
 		purge_vmap_area_lazy();
 		purged = 1;
@@ -1177,28 +1180,25 @@ int unregister_vmap_purge_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
 
-static void __free_vmap_area(struct vmap_area *va)
+/*
+ * Free a region of KVA allocated by alloc_vmap_area
+ */
+static void free_vmap_area(struct vmap_area *va)
 {
 	/*
 	 * Remove from the busy tree/list.
 	 */
+	spin_lock(&vmap_area_lock);
 	unlink_va(va, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
 
 	/*
-	 * Merge VA with its neighbors, otherwise just add it.
+	 * Insert/Merge it back to the free tree/list.
 	 */
+	spin_lock(&free_vmap_area_lock);
 	merge_or_add_vmap_area(va,
 		&free_vmap_area_root, &free_vmap_area_list);
-}
-
-/*
- * Free a region of KVA allocated by alloc_vmap_area
- */
-static void free_vmap_area(struct vmap_area *va)
-{
-	spin_lock(&vmap_area_lock);
-	__free_vmap_area(va);
-	spin_unlock(&vmap_area_lock);
+	spin_unlock(&free_vmap_area_lock);
 }
 
 /*
@@ -1291,7 +1291,7 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
 	flush_tlb_kernel_range(start, end);
 	resched_threshold = lazy_max_pages() << 1;
 
-	spin_lock(&vmap_area_lock);
+	spin_lock(&free_vmap_area_lock);
 	llist_for_each_entry_safe(va, n_va, valist, purge_list) {
 		unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
 
@@ -1306,9 +1306,9 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
 		atomic_long_sub(nr, &vmap_lazy_nr);
 
 		if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
-			cond_resched_lock(&vmap_area_lock);
+			cond_resched_lock(&free_vmap_area_lock);
 	}
-	spin_unlock(&vmap_area_lock);
+	spin_unlock(&free_vmap_area_lock);
 	return true;
 }
 
@@ -2030,15 +2030,21 @@ int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
 }
 EXPORT_SYMBOL_GPL(map_vm_area);
 
-static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
-			      unsigned long flags, const void *caller)
+static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
+	struct vmap_area *va, unsigned long flags, const void *caller)
 {
-	spin_lock(&vmap_area_lock);
 	vm->flags = flags;
 	vm->addr = (void *)va->va_start;
 	vm->size = va->va_end - va->va_start;
 	vm->caller = caller;
 	va->vm = vm;
+}
+
+static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+			      unsigned long flags, const void *caller)
+{
+	spin_lock(&vmap_area_lock);
+	setup_vmalloc_vm_locked(vm, va, flags, caller);
 	spin_unlock(&vmap_area_lock);
 }
 
@@ -3298,7 +3304,7 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 			goto err_free;
 	}
 retry:
-	spin_lock(&vmap_area_lock);
+	spin_lock(&free_vmap_area_lock);
 
 	/* start scanning - we scan from the top, begin with the last area */
 	area = term_area = last_area;
@@ -3380,29 +3386,38 @@ retry:
 		va = vas[area];
 		va->va_start = start;
 		va->va_end = start + size;
-
-		insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
 	}
 
-	spin_unlock(&vmap_area_lock);
+	spin_unlock(&free_vmap_area_lock);
 
 	/* insert all vm's */
-	for (area = 0; area < nr_vms; area++)
-		setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+	spin_lock(&vmap_area_lock);
+	for (area = 0; area < nr_vms; area++) {
+		insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list);
+
+		setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
 				 pcpu_get_vm_areas);
+	}
+	spin_unlock(&vmap_area_lock);
 
 	kfree(vas);
 	return vms;
 
 recovery:
-	/* Remove previously inserted areas. */
+	/*
+	 * Remove previously allocated areas. There is no
+	 * need in removing these areas from the busy tree,
+	 * because they are inserted only on the final step
+	 * and when pcpu_get_vm_areas() is success.
+	 */
 	while (area--) {
-		__free_vmap_area(vas[area]);
+		merge_or_add_vmap_area(vas[area],
+			&free_vmap_area_root, &free_vmap_area_list);
 		vas[area] = NULL;
 	}
 
 overflow:
-	spin_unlock(&vmap_area_lock);
+	spin_unlock(&free_vmap_area_lock);
 	if (!purged) {
 		purge_vmap_area_lazy();
 		purged = true;
@@ -3453,9 +3468,12 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 
 #ifdef CONFIG_PROC_FS
 static void *s_start(struct seq_file *m, loff_t *pos)
+	__acquires(&vmap_purge_lock)
 	__acquires(&vmap_area_lock)
 {
+	mutex_lock(&vmap_purge_lock);
 	spin_lock(&vmap_area_lock);
+
 	return seq_list_start(&vmap_area_list, *pos);
 }
 
@@ -3465,8 +3483,10 @@ static void *s_next(struct seq_file *m, void *p, loff_t *pos)
 }
 
 static void s_stop(struct seq_file *m, void *p)
+	__releases(&vmap_purge_lock)
 	__releases(&vmap_area_lock)
 {
+	mutex_unlock(&vmap_purge_lock);
 	spin_unlock(&vmap_area_lock);
 }