ovl: whiteout index when union nlink drops to zero
With NFS export feature enabled, when overlay inode nlink drops to
zero, instead of removing the index entry, replace it with a whiteout
index entry.
This is needed for NFS export in order to prevent future open by handle
from opening the lower file directly.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 6b11e11..aa2234d 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -487,7 +487,8 @@
/* Caller must hold OVL_I(inode)->lock */
static void ovl_cleanup_index(struct dentry *dentry)
{
- struct inode *dir = ovl_indexdir(dentry->d_sb)->d_inode;
+ struct dentry *indexdir = ovl_indexdir(dentry->d_sb);
+ struct inode *dir = indexdir->d_inode;
struct dentry *lowerdentry = ovl_dentry_lower(dentry);
struct dentry *upperdentry = ovl_dentry_upper(dentry);
struct dentry *index = NULL;
@@ -518,13 +519,17 @@
}
inode_lock_nested(dir, I_MUTEX_PARENT);
- /* TODO: whiteout instead of cleanup to block future open by handle */
- index = lookup_one_len(name.name, ovl_indexdir(dentry->d_sb), name.len);
+ index = lookup_one_len(name.name, indexdir, name.len);
err = PTR_ERR(index);
- if (!IS_ERR(index))
- err = ovl_cleanup(dir, index);
- else
+ if (IS_ERR(index)) {
index = NULL;
+ } else if (ovl_index_all(dentry->d_sb)) {
+ /* Whiteout orphan index to block future open by handle */
+ err = ovl_cleanup_and_whiteout(indexdir, dir, index);
+ } else {
+ /* Cleanup orphan index entries */
+ err = ovl_cleanup(dir, index);
+ }
inode_unlock(dir);
if (err)