On Fri 20-06-25 15:17:28, Qu Wenruo wrote:
> Currently we already have the super_operations::shutdown() callback,
> which is called when the block device of a filesystem is marked dead.
>
> However this is mostly for single(ish) block device filesystems.
>
> For multi-device filesystems, they may afford a missing device, thus may
> continue work without fully shutdown the filesystem.
>
> So add a new super_operation::shutdown_bdev() callback, for mutli-device
> filesystems like btrfs and bcachefs.
>
> For now the only user is fs_holder_ops::mark_dead(), which will call
> shutdown_bdev() if supported.
> If not supported then fallback to the original shutdown() callback.
>
> Btrfs is going to add the usage of shutdown_bdev() soon.
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Thanks for the patch. I think that we could actually add 'bdev' that
triggered shutdown among arguments ->shutdown takes instead of introducing
a new handler.
Honza
> ---
> fs/super.c | 4 +++-
> include/linux/fs.h | 10 ++++++++++
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/fs/super.c b/fs/super.c
> index 21799e213fd7..8242a03bd5ce 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -1461,7 +1461,9 @@ static void fs_bdev_mark_dead(struct block_device *bdev, bool surprise)
> sync_filesystem(sb);
> shrink_dcache_sb(sb);
> evict_inodes(sb);
> - if (sb->s_op->shutdown)
> + if (sb->s_op->shutdown_bdev)
> + sb->s_op->shutdown_bdev(sb, bdev);
> + else if (sb->s_op->shutdown)
> sb->s_op->shutdown(sb);
>
> super_unlock_shared(sb);
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 96c7925a6551..4f6b4b3cbe22 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2363,7 +2363,17 @@ struct super_operations {
> struct shrink_control *);
> long (*free_cached_objects)(struct super_block *,
> struct shrink_control *);
> + /*
> + * For single-device filesystems. Called when the only block device is
> + * marked dead.
> + */
> void (*shutdown)(struct super_block *sb);
> +
> + /*
> + * For multi-device filesystems. Called when any of its block device is
> + * marked dead.
> + */
> + void (*shutdown_bdev)(struct super_block *sb, struct block_device *bdev);
> };
>
> /*
> --
> 2.49.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
