diff mbox series

[10/13] procfs: make freeing proc_fs_info rcu-delayed

Message ID 20240204021739.1157830-10-viro@zeniv.linux.org.uk (mailing list archive)
State New, archived
Headers show
Series [01/13] fs/super.c: don't drop ->s_user_ns until we free struct super_block itself | expand

Commit Message

Al Viro Feb. 4, 2024, 2:17 a.m. UTC
makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
is still synchronous, but that's not a problem - it does
rcu-delay everything that needs to be)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/proc/root.c          | 2 +-
 include/linux/proc_fs.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

Comments

Christian Brauner Feb. 5, 2024, 12:31 p.m. UTC | #1
On Sun, Feb 04, 2024 at 02:17:36AM +0000, Al Viro wrote:
> makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
> is still synchronous, but that's not a problem - it does
> rcu-delay everything that needs to be)
> 
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---

Reviewed-by: Christian Brauner <brauner@kernel.org>
diff mbox series

Patch

diff --git a/fs/proc/root.c b/fs/proc/root.c
index b55dbc70287b..06a297a27ba3 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -271,7 +271,7 @@  static void proc_kill_sb(struct super_block *sb)
 
 	kill_anon_super(sb);
 	put_pid_ns(fs_info->pid_ns);
-	kfree(fs_info);
+	kfree_rcu(fs_info, rcu);
 }
 
 static struct file_system_type proc_fs_type = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index de407e7c3b55..0b2a89854440 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -65,6 +65,7 @@  struct proc_fs_info {
 	kgid_t pid_gid;
 	enum proc_hidepid hide_pid;
 	enum proc_pidonly pidonly;
+	struct rcu_head rcu;
 };
 
 static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)