This is a note to let you know that I've just added the patch titled debugfs: do not attempt to create a new file before the filesystem is to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the driver-core-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 56348560d495d2501e87db559a61de717cd3ab02 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Date: Thu, 18 Feb 2021 11:08:18 +0100 Subject: debugfs: do not attempt to create a new file before the filesystem is initalized Some subsystems want to add debugfs files at early boot, way before debugfs is initialized. This seems to work somehow as the vfs layer will not allow it to happen, but let's be explicit and test to ensure we are properly up and running before allowing files to be created. Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Reported-by: Michael Walle <michael@xxxxxxxx> Reported-by: Marc Zyngier <maz@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210218100818.3622317-2-gregkh@xxxxxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/debugfs/inode.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index bbeb563cbe78..86c7f0489620 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -318,6 +318,9 @@ static struct dentry *start_creating(const char *name, struct dentry *parent) if (!(debugfs_allow & DEBUGFS_ALLOW_API)) return ERR_PTR(-EPERM); + if (!debugfs_initialized()) + return ERR_PTR(-ENOENT); + pr_debug("creating file '%s'\n", name); if (IS_ERR(parent)) -- 2.30.1