On Mon, 2008-04-07 at 13:56 -0400, J. Bruce Fields wrote: > On Mon, Apr 07, 2008 at 12:45:01PM -0400, Christoph Hellwig wrote: > > On Mon, Apr 07, 2008 at 09:38:34AM -0400, Jeff Layton wrote: > > > The global task and serv pointers for lockd are normally protected by > > > the nlmsvc_mutex. The exception is when the lockd exits abnormally. When > > > this occurs, these variables are cleared without any locking. > > > > Shouldn't we get rid of the case where it exits abnormally instead? > > I tried to figure out when this could actually occur (when can > svc_recv() return an error other than -EINTR or -EAGAIN?), and got lost > in sock_recvmsg(): > > - svc_recv() itself returns only -EAGAIN or the return from > ->xpo_recvfrom(). > - the only xpo_recvfrom() that's interesting is > svc_tcp_recvfrom(), which can return the error it gets from > svc_recvfrom(), which can return the error from > kernel_recvmsg(), which gets its return from sock_recvmsg(). > > Since __sock_recvmsg() has a security hook, it looks like we can end up > with an -EACCES from selinux? FWIW: I believe that if svc_recv returns anything other then -EINTR or -EAGAIN, the service thread exits. I believe that the current design (could be broken) is that if the transport finds an error, the action is to set the XPT_CLOSE bit, enqueue the transport and return -EAGAIN. This will cause the service thread to call svc_recv again and close processing to occur. > > So one case would be selinux deciding we weren't allowed to receive > packets from this socket. Huh. > > --b. > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
