Merge tag 'tracefs-v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...

Merge tag 'tracefs-v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracefs fixes from Steven Rostedt:

 - Use list_add_tail_rcu() for walking eventfs children

   The linked list of children is protected by SRCU and list walkers can
   walk the list with only using SRCU. Using just list_add_tail() on
   weakly ordered architectures can cause issues. Instead use
   list_add_tail_rcu().

 - Hold eventfs_mutex and SRCU for remount walk events

   The trace_apply_options() walks the tracefs_inodes where some are
   eventfs inodes and eventfs_remount() is called which in turn calls
   eventfs_set_attr(). This walk only holds normal RCU read locks, but
   the eventfs_mutex and SRCU should be held.

   Add a eventfs_remount_(un)lock() helpers to take the necessary locks
   before iterating the list.

* tag 'tracefs-v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Hold eventfs_mutex and SRCU when remount walks events
  eventfs: Use list_add_tail_rcu() for SRCU-protected children list