aufs: bugfix, fc->root may not be real root

If the subdir in aufs is "bind" mounted and remount is issued, fs_context gives us the bound non-root dentry as if it were root. But aufs expects fc->root being always root. See-also: sfjro/aufs-standalone#40 Signed-off-by: J. R. Okajima <[email protected]>
sfjro · Jun 24, 2024 · b9f7afc · b9f7afc
1 parent f52c34d
commit b9f7afc
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/fs/aufs/fsctx.c b/fs/aufs/fsctx.c
@@ -47,6 +47,8 @@ static int au_fsctx_reconfigure(struct fs_context *fc)
 
 	root = fc->root;
 	sb = root->d_sb;
+	root = sb->s_root; /* "bind"-mount may give us non-root */
+	AuDebugOn(!IS_ROOT(root));
 	err = si_write_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
 	if (!err) {
 		di_write_lock_child(root);