From: "Steven Rostedt (Google)" rostedt@goodmis.org
As the comment right above a WARN_ON() in create_file_dentry() states:
* Note, with the mutex held, the e_dentry cannot have content * and the ei->is_freed be true at the same time.
But the WARN_ON() only has:
WARN_ON_ONCE(ei->is_free);
Where to match the comment (and what it should actually do) is:
dentry = *e_dentry; WARN_ON_ONCE(dentry && ei->is_free)
Also in that case, set dentry to NULL (although it should never happen).
Link: https://lore.kernel.org/linux-trace-kernel/20231024123628.62b88755@gandalf.l...
Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Mark Rutland mark.rutland@arm.com Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org (cherry picked from commit a9de4eb15ad430fe45747c211e367da745a90093) --- fs/tracefs/event_inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 09ab93357957..4d2da7480e5f 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -264,8 +264,9 @@ create_file_dentry(struct eventfs_inode *ei, struct dentry **e_dentry, * Note, with the mutex held, the e_dentry cannot have content * and the ei->is_freed be true at the same time. */ - WARN_ON_ONCE(ei->is_freed); dentry = *e_dentry; + if (WARN_ON_ONCE(dentry && ei->is_freed)) + dentry = NULL; /* The lookup does not need to up the dentry refcount */ if (dentry && !lookup) dget(dentry);