2023-03-15 18:19:45

by Joel Fernandes

Subject: [PATCH v2 07/14] ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()

From: "Uladzislau Rezki (Sony)" <[email protected]>

The kfree_rcu() and kvfree_rcu() macros' single-argument forms are
deprecated. Therefore switch to the new kfree_rcu_mightsleep() and
kvfree_rcu_mightsleep() variants. The goal is to avoid accidental use
of the single-argument forms, which can introduce functionality bugs in
atomic contexts and latency bugs in non-atomic contexts.

Cc: Theodore Ts'o <[email protected]>
Cc: Lukas Czerner <[email protected]>
Signed-off-by: Uladzislau Rezki (Sony) <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Signed-off-by: Joel Fernandes (Google) <[email protected]>
---
fs/ext4/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 88f7b8a88c76..405a66b47311 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2500,7 +2500,7 @@ static void ext4_apply_quota_options(struct fs_context *fc,
qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
lockdep_is_held(&sb->s_umount));
if (qname)
- kfree_rcu(qname);
+ kfree_rcu_mightsleep(qname);
}
}

--
2.40.0.rc1.284.g88254d51c5-goog

2023-03-15 19:08:10

by Theodore Ts'o

Subject: Re: [PATCH v2 07/14] ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()

On Wed, Mar 15, 2023 at 06:18:54PM +0000, Joel Fernandes (Google) wrote:
> From: "Uladzislau Rezki (Sony)" <[email protected]>
>
> The kfree_rcu() and kvfree_rcu() macros' single-argument forms are
> deprecated. Therefore switch to the new kfree_rcu_mightsleep() and
> kvfree_rcu_mightsleep() variants. The goal is to avoid accidental use
> of the single-argument forms, which can introduce functionality bugs in
> atomic contexts and latency bugs in non-atomic contexts.
>
> Cc: Theodore Ts'o <[email protected]>
> Cc: Lukas Czerner <[email protected]>
> Signed-off-by: Uladzislau Rezki (Sony) <[email protected]>
> Signed-off-by: Paul E. McKenney <[email protected]>
> Signed-off-by: Joel Fernandes (Google) <[email protected]>

Acked-by: Theodore Ts'o <[email protected]>

2023-03-16 15:23:52

by Joel Fernandes

Subject: Re: [PATCH v2 07/14] ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()

On Wed, Mar 15, 2023 at 3:07 PM Theodore Ts'o <[email protected]> wrote:
>
> On Wed, Mar 15, 2023 at 06:18:54PM +0000, Joel Fernandes (Google) wrote:
> > From: "Uladzislau Rezki (Sony)" <[email protected]>
> >
> > The kfree_rcu() and kvfree_rcu() macros' single-argument forms are
> > deprecated. Therefore switch to the new kfree_rcu_mightsleep() and
> > kvfree_rcu_mightsleep() variants. The goal is to avoid accidental use
> > of the single-argument forms, which can introduce functionality bugs in
> > atomic contexts and latency bugs in non-atomic contexts.
> >
> > Cc: Theodore Ts'o <[email protected]>
> > Cc: Lukas Czerner <[email protected]>
> > Signed-off-by: Uladzislau Rezki (Sony) <[email protected]>
> > Signed-off-by: Paul E. McKenney <[email protected]>
> > Signed-off-by: Joel Fernandes (Google) <[email protected]>
>
> Acked-by: Theodore Ts'o <[email protected]>
>

Thanks!

- Joel