ovl: mark upper merge dir with type origin entries "impure"
An upper dir is marked "impure" to let ovl_iterate() know that this
directory may contain non pure upper entries whose d_ino may need to be
read from the origin inode.
We already mark a non-merge dir "impure" when moving a non-pure child
entry inside it, to let ovl_iterate() know not to iterate the non-merge
dir directly.
Mark also a merge dir "impure" when moving a non-pure child entry inside
it and when copying up a child entry inside it.
This can be used to optimize ovl_iterate() to perform a "pure merge" of
upper and lower directories, merging the content of the directories,
without having to read d_ino from origin inodes.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index f2a118b..a63a716 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -149,22 +149,6 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
return ovl_set_opaque_xerr(dentry, upperdentry, -EIO);
}
-static int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry)
-{
- int err;
-
- /*
- * Do not fail when upper doesn't support xattrs.
- * Upper inodes won't have origin nor redirect xattr anyway.
- */
- err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE,
- "y", 1, 0);
- if (!err)
- ovl_dentry_set_impure(dentry);
-
- return err;
-}
-
/* Common operations required to be done after creation of file on upper */
static void ovl_instantiate(struct dentry *dentry, struct inode *inode,
struct dentry *newdentry, bool hardlink)
@@ -976,21 +960,16 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
if (!samedir) {
/*
* When moving a merge dir or non-dir with copy up origin into
- * a non-merge upper dir (a.k.a pure upper dir), we are making
- * the target parent dir "impure". ovl_iterate() iterates pure
- * upper dirs directly, because there is no need to filter out
- * whiteouts and merge dir content with lower dir. But for the
- * case of an "impure" upper dir, ovl_iterate() cannot iterate
- * the real directory directly, because it looks for the inode
- * numbers to fill d_ino in the entries origin inode.
+ * a new parent, we are marking the new parent dir "impure".
+ * When ovl_iterate() iterates an "impure" upper dir, it will
+ * lookup the origin inodes of the entries to fill d_ino.
*/
- if (ovl_type_origin(old) && !ovl_type_merge(new->d_parent)) {
+ if (ovl_type_origin(old)) {
err = ovl_set_impure(new->d_parent, new_upperdir);
if (err)
goto out_revert_creds;
}
- if (!overwrite && ovl_type_origin(new) &&
- !ovl_type_merge(old->d_parent)) {
+ if (!overwrite && ovl_type_origin(new)) {
err = ovl_set_impure(old->d_parent, old_upperdir);
if (err)
goto out_revert_creds;