ceph: Fix __ceph_do_pending_vmtruncate

we should set i_truncate_pending to 0 after page cache is truncated
to i_truncate_size
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit a85f50b6)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ceph/inode.c

@@ -1466,7 +1466,7 @@ void __ceph_do_pending_vmtruncate(struct inode *inode)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	u64 to;
-	int wrbuffer_refs, wake = 0;
+	int wrbuffer_refs, finish = 0;
 
 retry:
 	spin_lock(&ci->i_ceph_lock);
@@ -1498,15 +1498,18 @@ void __ceph_do_pending_vmtruncate(struct inode *inode)
 	truncate_inode_pages(inode->i_mapping, to);
 
 	spin_lock(&ci->i_ceph_lock);
-	ci->i_truncate_pending--;
-	if (ci->i_truncate_pending == 0)
-		wake = 1;
+	if (to == ci->i_truncate_size) {
+		ci->i_truncate_pending = 0;
+		finish = 1;
+	}
 	spin_unlock(&ci->i_ceph_lock);
+	if (!finish)
+		goto retry;
 
 	if (wrbuffer_refs == 0)
 		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
-	if (wake)
-		wake_up_all(&ci->i_cap_wq);
+
+	wake_up_all(&ci->i_cap_wq);
 }