From: "Steven Rostedt (Google)" rostedt@goodmis.org
There should never be a case where an evenfs_inode is being freed without is_freed being set. Add a WARN_ON_ONCE() if it ever happens. That would mean there was one too many put_ei()s.
Link: https://lore.kernel.org/linux-trace-kernel/20240201161616.843551963@goodmis....
Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Mathieu Desnoyers mathieu.desnoyers@efficios.com Cc: Christian Brauner brauner@kernel.org Cc: Al Viro viro@ZenIV.linux.org.uk Cc: Ajay Kaher ajay.kaher@broadcom.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org (cherry picked from commit 5a49f996046ba947466bc7461e4b19c4d1daf978) --- fs/tracefs/event_inode.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 515fdace1eea..ca7daee7c811 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -73,6 +73,9 @@ enum { static void release_ei(struct kref *ref) { struct eventfs_inode *ei = container_of(ref, struct eventfs_inode, kref); + + WARN_ON_ONCE(!ei->is_freed); + kfree(ei->entry_attrs); kfree_const(ei->name); kfree_rcu(ei, rcu); @@ -84,6 +87,14 @@ static inline void put_ei(struct eventfs_inode *ei) kref_put(&ei->kref, release_ei); }
+static inline void free_ei(struct eventfs_inode *ei) +{ + if (ei) { + ei->is_freed = 1; + put_ei(ei); + } +} + static inline struct eventfs_inode *get_ei(struct eventfs_inode *ei) { if (ei) @@ -679,7 +690,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode
/* Was the parent freed? */ if (list_empty(&ei->list)) { - put_ei(ei); + free_ei(ei); ei = NULL; } return ei; @@ -770,7 +781,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry return ei;
fail: - put_ei(ei); + free_ei(ei); tracefs_failed_creating(dentry); return ERR_PTR(-ENOMEM); } @@ -801,9 +812,8 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) list_for_each_entry(ei_child, &ei->children, list) eventfs_remove_rec(ei_child, level + 1);
- ei->is_freed = 1; list_del(&ei->list); - put_ei(ei); + free_ei(ei); }
/**