On Tue, Apr 01, 2025 at 02:32:48AM +0200, Christian Brauner wrote:
> From: Luis Chamberlain <mcgrof@xxxxxxxxxx>
>
> The kernel power management now supports allowing the VFS
> to handle filesystem freezing freezes and thawing. Take advantage
> of that and remove the kthread freezing. This is needed so that we
> properly really stop IO in flight without races after userspace
> has been frozen. Without this we rely on kthread freezing and
> its semantics are loose and error prone.
>
> The filesystem therefore is in charge of properly dealing with
> quiescing of the filesystem through its callbacks if it thinks
> it knows better than how the VFS handles it.
>
.....
> diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
> index 0fcb1828e598..ad8183db0780 100644
> --- a/fs/xfs/xfs_trans_ail.c
> +++ b/fs/xfs/xfs_trans_ail.c
> @@ -636,7 +636,6 @@ xfsaild(
> unsigned int noreclaim_flag;
>
> noreclaim_flag = memalloc_noreclaim_save();
> - set_freezable();
>
> while (1) {
> /*
> @@ -695,8 +694,6 @@ xfsaild(
>
> __set_current_state(TASK_RUNNING);
>
> - try_to_freeze();
> -
> tout = xfsaild_push(ailp);
> }
>
So what about the TASK_FREEZABLE flag that is set in this code
before sleeping?
i.e. this code before we schedule():
if (tout && tout <= 20)
set_current_state(TASK_KILLABLE|TASK_FREEZABLE);
else
set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
Shouldn't TASK_FREEZABLE go away, too?
> diff --git a/fs/xfs/xfs_zone_gc.c b/fs/xfs/xfs_zone_gc.c
> index c5136ea9bb1d..1875b6551ab0 100644
> --- a/fs/xfs/xfs_zone_gc.c
> +++ b/fs/xfs/xfs_zone_gc.c
> @@ -993,7 +993,6 @@ xfs_zone_gc_handle_work(
> }
>
> __set_current_state(TASK_RUNNING);
> - try_to_freeze();
>
> if (reset_list)
> xfs_zone_gc_reset_zones(data, reset_list);
> @@ -1041,7 +1040,6 @@ xfs_zoned_gcd(
> unsigned int nofs_flag;
>
> nofs_flag = memalloc_nofs_save();
> - set_freezable();
>
> for (;;) {
> set_current_state(TASK_INTERRUPTIBLE | TASK_FREEZABLE);
Same question here for this newly merged code, too...
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
