Re: [PATCH] sysfs: don't remove existing directory on update failure

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, May 20, 2026 at 03:06:03PM +0200, Greg Kroah-Hartman wrote:
> When sysfs_update_group() is called for a named group and create_files()
> fails (e.g. -ENOMEM), internal_create_group() calls kernfs_remove(kn) on
> the group directory.  In the update path, kn was obtained via
> kernfs_find_and_get() and refers to a directory that already existed
> before this call.  Removing it silently destroys a sysfs group that the
> caller did not create.
> 
> Only remove the directory if we created it ourselves.  On update failure
> the directory remains as it is left empty by remove_files() inside
> create_files(), but can be repopulated by a retry.
> 
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Danilo Krummrich <dakr@kernel.org>
> Cc: Rajat Jain <rajatja@google.com>
> Fixes: c855cf2759d2 ("sysfs: Fix internal_create_group() for named group updates")
> Cc: stable <stable@kernel.org>
> Assisted-by: gkh_clanker_t1000
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>  fs/sysfs/group.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
> index 182e54e575ee..4e1e4f18a166 100644
> --- a/fs/sysfs/group.c
> +++ b/fs/sysfs/group.c
> @@ -188,7 +188,7 @@ static int internal_create_group(struct kobject *kobj, int update,
>  	kernfs_get(kn);
>  	error = create_files(kn, kobj, uid, gid, grp, update);
>  	if (error) {
> -		if (grp->name)
> +		if (grp->name && !update)
>  			kernfs_remove(kn);
>  	}
>  	kernfs_put(kn);
> -- 
> 2.54.0
> 

Ugh, sent this twice, sorry for the noise, only one matters :)