From f565f3b06465725cae35f873d053cab14297eb73 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 1 Jun 2026 15:56:43 +0200 Subject: [PATCH] btrfs: use scoped_with_init_fs() for update_dev_time() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit update_dev_time() can be called from both kthread and process context. Use scoped_with_init_fs() to temporarily override current->fs for the kern_path() call when running in kthread context so the path lookup happens in init's filesystem context. update_dev_time() ← btrfs_scratch_superblocks() ← btrfs_dev_replace_finishing() ← btrfs_dev_replace_kthread() ← kthread (kthread_run) Also called from ioctl (user process). Link: https://patch.msgid.link/20260601-work-kthread-nullfs-v4-10-77ee053060e0@kernel.org Signed-off-by: Christian Brauner (Amutable) --- fs/btrfs/volumes.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 6eab4cc73ce4..dc5f4a122d55 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "misc.h" #include "disk-io.h" #include "extent-tree.h" @@ -2125,8 +2126,16 @@ static int btrfs_add_dev_item(struct btrfs_trans_handle *trans, static void update_dev_time(const char *device_path) { struct path path; + int err; - if (!kern_path(device_path, LOOKUP_FOLLOW, &path)) { + if (tsk_is_kthread(current)) { + scoped_with_init_fs() + err = kern_path(device_path, LOOKUP_FOLLOW, &path); + } else { + err = kern_path(device_path, LOOKUP_FOLLOW, &path); + } + + if (!err) { vfs_utimes(&path, NULL); path_put(&path); }