From c3a280ff728a9039c72cd64ad0b32bc3a28c25b2 Mon Sep 17 00:00:00 2001 From: Yohei Kojima Date: Thu, 11 Jun 2026 22:50:16 +0900 Subject: [PATCH] debugfs: warn if file creation failed due to uninitialized debugfs Improve debugfs_start_creating() to warn if it was used before debugfs initialization. It silently returned ERR_PTR(-ENOENT) before, but it is hard to find the cause of failure especially if it was called by debugfs_create_dir(), because the document of the function says: > NOTE: it's expected that most callers should _ignore_ the errors returned > by this function. Other debugfs functions handle the fact that the "dentry" > passed to them could be an error and they don't crash in that case. > Drivers should generally work fine even if debugfs fails to init anyway. Signed-off-by: Yohei Kojima Link: https://patch.msgid.link/6d1dc775f7d5e754d734907514534054f682bac5.1781171918.git.yk@y-koj.net Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/inode.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 4598142355b9..e054e62919ec 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -368,8 +368,11 @@ static struct dentry *debugfs_start_creating(const char *name, if (!debugfs_enabled) return ERR_PTR(-EPERM); - if (!debugfs_initialized()) + if (!debugfs_initialized()) { + pr_err("Unable to create file '%s', debugfs is not initialized yet\n", + name); return ERR_PTR(-ENOENT); + } pr_debug("creating file '%s'\n", name);