mm, hugetlb: use vma_resv_map() map types

Util now, we get a resv_map by two ways according to each mapping type.
This makes code dirty and unreadable.  Unify it.

[davidlohr@hp.com: code cleanups]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 45 insertions, 50 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c7918cd3a153..1c7baff65f9d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -419,13 +419,24 @@ void resv_map_release(struct kref *ref)
         kfree(resv_map);
 }
 
+static inline struct resv_map *inode_resv_map(struct inode *inode)
+{
+        return inode->i_mapping->private_data;
+}
+
 static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
 {
         VM_BUG_ON(!is_vm_hugetlb_page(vma));
-        if (!(vma->vm_flags & VM_MAYSHARE))
+        if (vma->vm_flags & VM_MAYSHARE) {
+                struct address_space *mapping = vma->vm_file->f_mapping;
+                struct inode *inode = mapping->host;
+
+                return inode_resv_map(inode);
+
+        } else {
                 return (struct resv_map *)(get_vma_private_data(vma) &
                                                         ~HPAGE_RESV_MASK);
-        return NULL;
+        }
 }
 
 static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
@@ -1167,48 +1178,34 @@ static void return_unused_surplus_pages(struct hstate *h,
 static long vma_needs_reservation(struct hstate *h,
                         struct vm_area_struct *vma, unsigned long addr)
 {
-        struct address_space *mapping = vma->vm_file->f_mapping;
-        struct inode *inode = mapping->host;
-
-        if (vma->vm_flags & VM_MAYSHARE) {
-                pgoff_t idx = vma_hugecache_offset(h, vma, addr);
-                struct resv_map *resv = inode->i_mapping->private_data;
-
-                return region_chg(resv, idx, idx + 1);
+        struct resv_map *resv;
+        pgoff_t idx;
+        long chg;
 
-        } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+        resv = vma_resv_map(vma);
+        if (!resv)
                 return 1;
 
-        } else  {
-                long err;
-                pgoff_t idx = vma_hugecache_offset(h, vma, addr);
-                struct resv_map *resv = vma_resv_map(vma);
+        idx = vma_hugecache_offset(h, vma, addr);
+        chg = region_chg(resv, idx, idx + 1);
 
-                err = region_chg(resv, idx, idx + 1);
-                if (err < 0)
-                        return err;
-                return 0;
-        }
+        if (vma->vm_flags & VM_MAYSHARE)
+                return chg;
+        else
+                return chg < 0 ? chg : 0;
 }
 static void vma_commit_reservation(struct hstate *h,
                         struct vm_area_struct *vma, unsigned long addr)
 {
-        struct address_space *mapping = vma->vm_file->f_mapping;
-        struct inode *inode = mapping->host;
-
-        if (vma->vm_flags & VM_MAYSHARE) {
-                pgoff_t idx = vma_hugecache_offset(h, vma, addr);
-                struct resv_map *resv = inode->i_mapping->private_data;
-
-                region_add(resv, idx, idx + 1);
+        struct resv_map *resv;
+        pgoff_t idx;
 
-        } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
-                pgoff_t idx = vma_hugecache_offset(h, vma, addr);
-                struct resv_map *resv = vma_resv_map(vma);
+        resv = vma_resv_map(vma);
+        if (!resv)
+                return;
 
-                /* Mark this page used in the map. */
-                region_add(resv, idx, idx + 1);
-        }
+        idx = vma_hugecache_offset(h, vma, addr);
+        region_add(resv, idx, idx + 1);
 }
 
 static struct page *alloc_huge_page(struct vm_area_struct *vma,
@@ -2271,7 +2268,7 @@ static void hugetlb_vm_op_open(struct vm_area_struct *vma)
          * after this open call completes.  It is therefore safe to take a
          * new reference here without additional locking.
          */
-        if (resv)
+        if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
                 kref_get(&resv->refs);
 }
 
@@ -2280,23 +2277,21 @@ static void hugetlb_vm_op_close(struct vm_area_struct *vma)
         struct hstate *h = hstate_vma(vma);
         struct resv_map *resv = vma_resv_map(vma);
         struct hugepage_subpool *spool = subpool_vma(vma);
-        unsigned long reserve;
-        unsigned long start;
-        unsigned long end;
+        unsigned long reserve, start, end;
 
-        if (resv) {
-                start = vma_hugecache_offset(h, vma, vma->vm_start);
-                end = vma_hugecache_offset(h, vma, vma->vm_end);
+        if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER))
+                return;
 
-                reserve = (end - start) -
-                        region_count(resv, start, end);
+        start = vma_hugecache_offset(h, vma, vma->vm_start);
+        end = vma_hugecache_offset(h, vma, vma->vm_end);
 
-                kref_put(&resv->refs, resv_map_release);
+        reserve = (end - start) - region_count(resv, start, end);
 
-                if (reserve) {
-                        hugetlb_acct_memory(h, -reserve);
-                        hugepage_subpool_put_pages(spool, reserve);
-                }
+        kref_put(&resv->refs, resv_map_release);
+
+        if (reserve) {
+                hugetlb_acct_memory(h, -reserve);
+                hugepage_subpool_put_pages(spool, reserve);
         }
 }
 
@@ -3189,7 +3184,7 @@ int hugetlb_reserve_pages(struct inode *inode,
          * called to make the mapping read-write. Assume !vma is a shm mapping
          */
         if (!vma || vma->vm_flags & VM_MAYSHARE) {
-                resv_map = inode->i_mapping->private_data;
+                resv_map = inode_resv_map(inode);
 
                 chg = region_chg(resv_map, from, to);
 
@@ -3248,7 +3243,7 @@ out_err:
 void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
 {
         struct hstate *h = hstate_inode(inode);
-        struct resv_map *resv_map = inode->i_mapping->private_data;
+        struct resv_map *resv_map = inode_resv_map(inode);
         long chg = 0;
         struct hugepage_subpool *spool = subpool_inode(inode);