On Thu, Aug 29, 2024 at 1:15 PM Jan Kara <jack@xxxxxxx> wrote: > > On Wed 14-08-24 17:25:33, Josef Bacik wrote: > > gfs2 takes the glock before calling into filemap fault, so add the > > fsnotify hook for ->fault before we take the glock in order to avoid any > > possible deadlock with the HSM. > > > > Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > > The idea of interactions between GFS2 cluster locking and HSM gives me > creeps. But yes, this patch looks good to me. Would be nice to get ack from > GFS2 guys. Andreas? If we are being honest, I think that the fact that HSM events require careful handling in ->fault() and not to mention no documentation of this fact, perhaps we should let HSM events be an opt-in file_system_type feature? Additionally, we had to introduce FS_DISALLOW_NOTIFY_PERM and restrict sb marks on SB_NOUSER, all because these fanotify features did not require fs opt-in to begin with. I think we would be repeating this mistake if we do not add FS_ALLOW_HSM from the start. After all, I cannot imagine HSM being used on anything but the major disk filesystems. Hmm? Amir.
