vmalloc: separate out insert_vmalloc_vm()

Separate out insert_vmalloc_vm() from __get_vm_area_node().
insert_vmalloc_vm() initializes vm_struct from vmap_area and inserts
it into vmlist.  insert_vmalloc_vm() only initializes fields which can
be determined from @vm, @flags and @caller The rest should be
initialized by the caller.  For __get_vm_area_node(), all other fields
just need to be cleared and this is done by using kzalloc instead of
kmalloc.

This will be used to implement pcpu_get_vm_areas().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>

1 files changed, 24 insertions, 21 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index f8189a4b3e13..2eb461c3a46e 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1122,13 +1122,34 @@ EXPORT_SYMBOL_GPL(map_vm_area);
 DEFINE_RWLOCK(vmlist_lock);
 struct vm_struct *vmlist;
 
+static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+                              unsigned long flags, void *caller)
+{
+        struct vm_struct *tmp, **p;
+
+        vm->flags = flags;
+        vm->addr = (void *)va->va_start;
+        vm->size = va->va_end - va->va_start;
+        vm->caller = caller;
+        va->private = vm;
+        va->flags |= VM_VM_AREA;
+
+        write_lock(&vmlist_lock);
+        for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+                if (tmp->addr >= vm->addr)
+                        break;
+        }
+        vm->next = *p;
+        *p = vm;
+        write_unlock(&vmlist_lock);
+}
+
 static struct vm_struct *__get_vm_area_node(unsigned long size,
                 unsigned long flags, unsigned long start, unsigned long end,
                 int node, gfp_t gfp_mask, void *caller)
 {
         static struct vmap_area *va;
         struct vm_struct *area;
-        struct vm_struct *tmp, **p;
         unsigned long align = 1;
 
         BUG_ON(in_interrupt());
@@ -1147,7 +1168,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
         if (unlikely(!size))
                 return NULL;
 
-        area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
+        area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
         if (unlikely(!area))
                 return NULL;
 
@@ -1162,25 +1183,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
                 return NULL;
         }
 
-        area->flags = flags;
-        area->addr = (void *)va->va_start;
-        area->size = size;
-        area->pages = NULL;
-        area->nr_pages = 0;
-        area->phys_addr = 0;
-        area->caller = caller;
-        va->private = area;
-        va->flags |= VM_VM_AREA;
-
-        write_lock(&vmlist_lock);
-        for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
-                if (tmp->addr >= area->addr)
-                        break;
-        }
-        area->next = *p;
-        *p = area;
-        write_unlock(&vmlist_lock);
-
+        insert_vmalloc_vm(area, va, flags, caller);
         return area;
 }