X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Foverlayfs%2Freaddir.c;h=8c8ce9d87ba35cbe02a1607f3f2565e0f2bafc56;hb=d45f00ae43e63eff1b3d79df20610ae1ef645ebd;hp=910553f37acabbc22eaa21e793784d1b1a8b5af5;hpb=54ef6df3f3f1353d99c80c437259d317b2cd1cbd;p=firefly-linux-kernel-4.4.55.git

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 910553f37aca..8c8ce9d87ba3 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -454,12 +454,13 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
 	if (!od->is_upper && ovl_path_type(dentry) == OVL_PATH_MERGE) {
 		struct inode *inode = file_inode(file);
 
-		realfile = od->upperfile;
+		realfile =lockless_dereference(od->upperfile);
 		if (!realfile) {
 			struct path upperpath;
 
 			ovl_path_upper(dentry, &upperpath);
 			realfile = ovl_path_open(&upperpath, O_RDONLY);
+			smp_mb__before_spinlock();
 			mutex_lock(&inode->i_mutex);
 			if (!od->upperfile) {
 				if (IS_ERR(realfile)) {