On Thu, 2025-03-13 at 20:47 +0000, David Howells wrote: > slava@xxxxxxxxxxx wrote: > > > What do you mean by mishandling? Do you imply that Ceph has to set up > > the I_NEW somehow? Is it not VFS responsibility? > > No - I mean that if I_NEW *isn't* set when the function is called, > ceph_fill_inode() will go and partially reinitialise the inode. Now, having > reviewed the code in more depth and talked to Jeff Layton about it, I think > that the non-I_NEW pass will only change pointers with some sort of locking > and will release the old target - though it may overwrite some pointers with > the same value without protection (i_fops for example). > > That said, if it's possible for *two* processes to be going through that > function without I_NEW set, you can get places where both of them will try > freeing the old data and replacing it with new without any locking - but I > don't know if that can happen. > I don't think that can happen. An I_NEW inode hasn't been properly hashed yet, so nothing should be able to find it until unlock_new_inode() is called. -- Jeff Layton <jlayton@xxxxxxxxxx>
