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/util.c b/fs/overlayfs/util.c
index e0dfb07..8090489 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -194,13 +194,6 @@ void ovl_dentry_set_opaque(struct dentry *dentry)
oe->opaque = true;
}
-void ovl_dentry_set_impure(struct dentry *dentry)
-{
- struct ovl_entry *oe = dentry->d_fsdata;
-
- oe->impure = true;
-}
-
bool ovl_redirect_dir(struct super_block *sb)
{
struct ovl_fs *ofs = sb->s_fs_info;
@@ -311,6 +304,21 @@ void ovl_copy_up_end(struct dentry *dentry)
spin_unlock(&ofs->copyup_wq.lock);
}
+bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)
+{
+ int res;
+ char val;
+
+ if (!d_is_dir(dentry))
+ return false;
+
+ res = vfs_getxattr(dentry, name, &val, 1);
+ if (res == 1 && val == 'y')
+ return true;
+
+ return false;
+}
+
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
const char *name, const void *value, size_t size,
int xerr)
@@ -331,3 +339,23 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
return err;
}
+
+int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry)
+{
+ int err;
+ struct ovl_entry *oe = dentry->d_fsdata;
+
+ if (oe->impure)
+ return 0;
+
+ /*
+ * 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)
+ oe->impure = true;
+
+ return err;
+}
