On Sun, Apr 01, 2018 at 02:48:54PM -0700, Eric Biggers wrote: > [+Cc linux-nfs] > > > > [ 42.965515] net/sunrpc/rpc_pipe.c: __rpc_create_common failed to allocate inode for dentry blocklayout > > [ 42.967234] net/sunrpc/rpc_pipe.c: rpc_mkpipe_dentry() failed to create pipe nfs/blocklayout (errno = -12) AFAICS, there's nothing to zero nn->bl_device_pipe->dentry after nfs4blocklayout_unregister_sb(), is there? If nothing else, what's going to happen after mount/umount/mount with failing nfs4blocklayout_register_sb()? AFAICS, we'll have stale pointer to dentry sitting in nn->bl_device_pipe->dentry, and call rpc_unlink() on it while cleaning up after the failing mount. I don't think that's all there is to it, but it does smell like a bug.