wrappers for ->i_mutex access

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 8bbf7f3..e1f465a 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -141,7 +141,7 @@
 
 	vma_len = (loff_t)(vma->vm_end - vma->vm_start);
 
-	mutex_lock(&inode->i_mutex);
+	inode_lock(inode);
 	file_accessed(file);
 
 	ret = -ENOMEM;
@@ -157,7 +157,7 @@
 	if (vma->vm_flags & VM_WRITE && inode->i_size < len)
 		inode->i_size = len;
 out:
-	mutex_unlock(&inode->i_mutex);
+	inode_unlock(inode);
 
 	return ret;
 }
@@ -530,7 +530,7 @@
 	if (hole_end > hole_start) {
 		struct address_space *mapping = inode->i_mapping;
 
-		mutex_lock(&inode->i_mutex);
+		inode_lock(inode);
 		i_mmap_lock_write(mapping);
 		if (!RB_EMPTY_ROOT(&mapping->i_mmap))
 			hugetlb_vmdelete_list(&mapping->i_mmap,
@@ -538,7 +538,7 @@
 						hole_end  >> PAGE_SHIFT);
 		i_mmap_unlock_write(mapping);
 		remove_inode_hugepages(inode, hole_start, hole_end);
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 	}
 
 	return 0;
@@ -572,7 +572,7 @@
 	start = offset >> hpage_shift;
 	end = (offset + len + hpage_size - 1) >> hpage_shift;
 
-	mutex_lock(&inode->i_mutex);
+	inode_lock(inode);
 
 	/* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */
 	error = inode_newsize_ok(inode, offset + len);
@@ -659,7 +659,7 @@
 		i_size_write(inode, offset + len);
 	inode->i_ctime = CURRENT_TIME;
 out:
-	mutex_unlock(&inode->i_mutex);
+	inode_unlock(inode);
 	return error;
 }