[PATCH] nilfs2: Add missing set_freezable() for freezable kthread

[PATCH] nilfs2: Add missing set_freezable() for freezable kthread

[Ryusuke Konishi]

From: Kevin Hao <haokexin@gmail.com>

The kernel thread function nilfs_segctor_thread() invokes
the try_to_freeze() in its loop. But all the kernel threads are
non-freezable by default. So if we want to make a kernel thread to be
freezable, we have to invoke set_freezable() explicitly.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
---
Andrew, please add this to the queue for the next merge window (if
it's still ok).  This fixes an issue where the log writer thread was
not calling try_to_freeze() as intended when starting suspend or
hibernation.

I haven't run into any problems with or without this change in various
suspend/hibernation tests so far, so I haven't added a Cc tag to the
stable team.

If any suspend failures are reported due to the lack of this setup,
I will separately request the stable team to backport this.

Thanks,
Ryusuke Konishi

fs/nilfs2/segment.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 52995838f2de..2590a0860eab 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2588,6 +2588,7 @@ static int nilfs_segctor_thread(void *arg)
 		   "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
 		   sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
 
+	set_freezable();
 	spin_lock(&sci->sc_state_lock);
  loop:
 	for (;;) {
-- 
2.34.1

[PATCH] nilfs2: Add missing set_freezable() for freezable kthread

[Kevin Hao]

The kernel thread function nilfs_segctor_thread() invokes
the try_to_freeze() in its loop. But all the kernel threads are
non-freezable by default. So if we want to make a kernel thread to be
freezable, we have to invoke set_freezable() explicitly.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 fs/nilfs2/segment.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 52995838f2de..2590a0860eab 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2588,6 +2588,7 @@ static int nilfs_segctor_thread(void *arg)
 		   "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
 		   sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
 
+	set_freezable();
 	spin_lock(&sci->sc_state_lock);
  loop:
 	for (;;) {
-- 
2.39.2

Re: [PATCH] nilfs2: Add missing set_freezable() for freezable kthread

[Ryusuke Konishi]

On Sun, Dec 17, 2023 at 10:50 PM Kevin Hao wrote:
>
> The kernel thread function nilfs_segctor_thread() invokes
> the try_to_freeze() in its loop. But all the kernel threads are
> non-freezable by default. So if we want to make a kernel thread to be
> freezable, we have to invoke set_freezable() explicitly.
>
> Signed-off-by: Kevin Hao <haokexin@gmail.com>
> ---
>  fs/nilfs2/segment.c | 1 +
>  1 file changed, 1 insertion(+)

Thank you!
I'll grab this and send it upstream.

Ryusuke Konishi

>
> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
> index 52995838f2de..2590a0860eab 100644
> --- a/fs/nilfs2/segment.c
> +++ b/fs/nilfs2/segment.c
> @@ -2588,6 +2588,7 @@ static int nilfs_segctor_thread(void *arg)
>                    "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
>                    sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
>
> +       set_freezable();
>         spin_lock(&sci->sc_state_lock);
>   loop:
>         for (;;) {
> --
> 2.39.2
>