mm: use new helper functions around the i_mmap_mutex

Convert all open coded mutex_lock/unlock calls to the
i_mmap_[lock/unlock]_write() helpers.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/nommu.c b/mm/nommu.c
index bd1808e..52a5765 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -722,11 +722,11 @@
 	if (vma->vm_file) {
 		mapping = vma->vm_file->f_mapping;
 
-		mutex_lock(&mapping->i_mmap_mutex);
+		i_mmap_lock_write(mapping);
 		flush_dcache_mmap_lock(mapping);
 		vma_interval_tree_insert(vma, &mapping->i_mmap);
 		flush_dcache_mmap_unlock(mapping);
-		mutex_unlock(&mapping->i_mmap_mutex);
+		i_mmap_unlock_write(mapping);
 	}
 
 	/* add the VMA to the tree */
@@ -795,11 +795,11 @@
 	if (vma->vm_file) {
 		mapping = vma->vm_file->f_mapping;
 
-		mutex_lock(&mapping->i_mmap_mutex);
+		i_mmap_lock_write(mapping);
 		flush_dcache_mmap_lock(mapping);
 		vma_interval_tree_remove(vma, &mapping->i_mmap);
 		flush_dcache_mmap_unlock(mapping);
-		mutex_unlock(&mapping->i_mmap_mutex);
+		i_mmap_unlock_write(mapping);
 	}
 
 	/* remove from the MM's tree and list */
@@ -2094,14 +2094,14 @@
 	high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 
 	down_write(&nommu_region_sem);
-	mutex_lock(&inode->i_mapping->i_mmap_mutex);
+	i_mmap_lock_write(inode->i_mapping);
 
 	/* search for VMAs that fall within the dead zone */
 	vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) {
 		/* found one - only interested if it's shared out of the page
 		 * cache */
 		if (vma->vm_flags & VM_SHARED) {
-			mutex_unlock(&inode->i_mapping->i_mmap_mutex);
+			i_mmap_unlock_write(inode->i_mapping);
 			up_write(&nommu_region_sem);
 			return -ETXTBSY; /* not quite true, but near enough */
 		}
@@ -2129,7 +2129,7 @@
 		}
 	}
 
-	mutex_unlock(&inode->i_mapping->i_mmap_mutex);
+	i_mmap_unlock_write(inode->i_mapping);
 	up_write(&nommu_region_sem);
 	return 0;
 }