On Fri, 27 Oct 2023 14:55:14 +0200
"Arnd Bergmann" <arnd@xxxxxxxx> wrote:
> This lock is part of the dentry passed to d_invalidate()
>
> > [ 1402.609170] ? lock_release (kernel/locking/lockdep.c:5429
> > kernel/locking/lockdep.c:5773)
> > [ 1402.612923] ? create_dir_dentry.part.0 (fs/tracefs/event_inode.c:387)
> > [ 1402.617803] _raw_spin_lock (include/linux/spinlock_api_smp.h:134
> > kernel/locking/spinlock.c:154)
> > [ 1402.621467] ? d_invalidate (fs/dcache.c:1725 (discriminator 1))
> > [ 1402.625126] d_invalidate (fs/dcache.c:1725 (discriminator 1))
> > [ 1402.628619] create_dir_dentry.part.0 (fs/tracefs/event_inode.c:390)
>
> Which is called by create_dir_dentry(). I don't see a bug
> in that function, but maybe Steve has an idea.
>
>
I see a bug ;-)
Can you test this patch?
Thanks!
-- Steve
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index 4d2da7480e5f..ef003149e4d3 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -234,6 +234,10 @@ create_file_dentry(struct eventfs_inode *ei, struct dentry **e_dentry,
bool invalidate = false;
mutex_lock(&eventfs_mutex);
+ if (ei->is_freed) {
+ mutex_unlock(&eventfs_mutex);
+ return NULL;
+ }
/* If the e_dentry already has a dentry, use it */
if (*e_dentry) {
/* lookup does not need to up the ref count */
@@ -333,6 +337,10 @@ create_dir_dentry(struct eventfs_inode *ei, struct dentry *parent, bool lookup)
struct dentry *dentry = NULL;
mutex_lock(&eventfs_mutex);
+ if (ei->is_freed) {
+ mutex_unlock(&eventfs_mutex);
+ return NULL;
+ }
if (ei->dentry) {
/* If the dentry already has a dentry, use it */
dentry = ei->dentry;
--
2.42.0
