1 files changed, 6 insertions, 1 deletions

diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 2efc57173fd7..266531343aae 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -131,6 +131,8 @@ static int ramfs_nommu_check_mappings(struct inode *inode,
         struct vm_area_struct *vma;
         struct prio_tree_iter iter;
 
+        down_write(&nommu_region_sem);
+
         /* search for VMAs that fall within the dead zone */
         vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap,
                               newsize >> PAGE_SHIFT,
@@ -138,10 +140,13 @@ static int ramfs_nommu_check_mappings(struct inode *inode,
                               ) {
                 /* found one - only interested if it's shared out of the page
                  * cache */
-                if (vma->vm_flags & VM_SHARED)
+                if (vma->vm_flags & VM_SHARED) {
+                        up_write(&nommu_region_sem);
                         return -ETXTBSY; /* not quite true, but near enough */
+                }
         }
 
+        up_write(&nommu_region_sem);
         return 0;
 }