On Mon, 2019-06-17 at 13:32 -0700, Patrick Donnelly wrote: > On Mon, Jun 17, 2019 at 5:56 AM Yan, Zheng <zyan@xxxxxxxxxx> wrote: > > After mds evicts session, file locks get lost sliently. It's not safe to > > let programs continue to do read/write. > > I think one issue with returning EIO on a file handle that did hold a > lock is that the application may be programmed to write to other files > assuming that lock is never lost, yes? In that case, it may not ever > write to the locked file in any case. > Sure, applications do all sorts of crazy things. We can only cater to so much craziness. I'll assert that most applications don't have these sorts of weirdo usage patterns, and an error on read/write is more reasonable. Note that this behavior is already documented in fcntl(2) as well, as is SIGLOST not being implemented. > Again, I'd like to see SIGLOST sent to the application here. Are there > any objections to reviving whatever patchset was in flight to add > that? Or just writeup a new one? > I think SIGLOST's utility is somewhat questionable. Applications will need to be custom-written to handle it. If you're going to do that, then it may be better to consider other async notification mechanisms. inotify or fanotify, perhaps? Those may be simpler to implement and get merged. -- Jeff Layton <jlayton@xxxxxxxxxx>
