Re: [PATCH 3/3] fs: move fscrypt keyring destruction to after ->put_super

Neal Gompa
2023-12-13T20:54:45Z

On Tue, Dec 12, 2023 at 11:01 PM Eric Biggers <ebiggers@kernel.org> wrote:
>
> From: Josef Bacik <josef@toxicpanda.com>
>
> btrfs has a variety of asynchronous things we do with inodes that can
> potentially last until ->put_super, when we shut everything down and
> clean up all of our async work. Due to this we need to move
> fscrypt_destroy_keyring() to after ->put_super, otherwise we get
> warnings about still having active references on the master key.
>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
> fs/super.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/fs/super.c b/fs/super.c
> index 076392396e724..faf7d248145d2 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -674,34 +674,34 @@ void generic_shutdown_super(struct super_block *sb)
> /* Evict all inodes with zero refcount. */
> evict_inodes(sb);
>
> /*
> * Clean up and evict any inodes that still have references due
> * to fsnotify or the security policy.
> */
> fsnotify_sb_delete(sb);
> security_sb_delete(sb);
>
> - /*
> - * Now that all potentially-encrypted inodes have been evicted,
> - * the fscrypt keyring can be destroyed.
> - */
> - fscrypt_destroy_keyring(sb);
> -
> if (sb->s_dio_done_wq) {
> destroy_workqueue(sb->s_dio_done_wq);
> sb->s_dio_done_wq = NULL;
> }
>
> if (sop->put_super)
> sop->put_super(sb);
>
> + /*
> + * Now that all potentially-encrypted inodes have been evicted,
> + * the fscrypt keyring can be destroyed.
> + */
> + fscrypt_destroy_keyring(sb);
> +
> if (CHECK_DATA_CORRUPTION(!list_empty(&sb->s_inodes),
> "VFS: Busy inodes after unmount of %s (%s)",
> sb->s_id, sb->s_type->name)) {
> /*
> * Adding a proper bailout path here would be hard, but
> * we can at least make it more likely that a later
> * iput_final() or such crashes cleanly.
> */
> struct inode *inode;
>
> --
> 2.43.0
>
>

This makes sense to me.

Reviewed-by: Neal Gompa <neal@gompa.dev>

--
真実はいつも一つ！/ Always, there's only one truth!