tracefs/eventfs: Use list_for_each_srcu() in dcache_dir_open_wrapper()

The eventfs files list is protected by SRCU. In earlier iterations it was
protected with just RCU, but because it needed to also call sleepable
code, it had to be switch to SRCU. The dcache_dir_open_wrapper()
list_for_each_rcu() was missed and did not get converted over to
list_for_each_srcu(). That needs to be fixed.

Link: https://lore.kernel.org/linux-trace-kernel/20230911120053.ca82f545e7f46ea753deda18@kernel.org/
Link: https://lore.kernel.org/linux-trace-kernel/20230911200654.71ce927c@gandalf.local.home
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ajay Kaher <akaher@vmware.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Reported-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fixes: 63940449555e7 ("eventfs: Implement eventfs lookup, read, open functions")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index f168aca4545870d4bce71a4a485a24d3c63bd48d..9f64e73327968edc286eaaa847249a4115fa2d49 100644 (file)
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -452,7 +452,8 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file)
 
        ei = ti->private;
        idx = srcu_read_lock(&eventfs_srcu);
-       list_for_each_entry_rcu(ef, &ei->e_top_files, list) {
+       list_for_each_entry_srcu(ef, &ei->e_top_files, list,
+                                srcu_read_lock_held(&eventfs_srcu)) {
                create_dentry(ef, dentry, false);
        }
        srcu_read_unlock(&eventfs_srcu, idx);