Recently a bug was found that was causing a TGT fetch for every mount upcall. The bug was caused when forking for every mount was introduce. The global memory for the TGT cache was being freed when the forked process existed. The fix we came up with was to only fork on non-root upcalls, basically mount upcalls would no longer fork. In debugging the patch it became apparent that if the process hung, all NFS mounts on that client would be blocked. So at this point rpc.gssd is a single point of failure. This patch replaces the forking/non-forking with creating pthreads for every upcall which I think is a better solution to the original problem since pthreads can share global data. I was also hoping using pthread would bring more asynchronous to rpc.gssd. I was thinking rpc.gssd could take an upcall, fire off a thread to handle it, the go back and listen for more upcalls. Unfortunately this is not the case. It seems, maybe due to my lack of my pthreads understanding, that after each pthread_create() call, a pthread_join() call, which waits for the created to stop, is needed. Similar to fork/wait.. This means if an upcall pthread gets hung the daemon is also hung... The same single point of failure... I do believe using threads is a better solution than the non-fork solution, but rpc.gssd is still a single point of failure. Plus I'm hoping moving to pthread will allow us to solve that problem. Steve Dickson (1): gssd: use pthreads to handle upcalls aclocal/libpthread.m4 | 13 +++++++++++++ configure.ac | 3 +++ utils/gssd/Makefile.am | 3 ++- utils/gssd/gssd.c | 18 ++++++++++++++++-- utils/gssd/gssd.h | 2 ++ utils/gssd/gssd_proc.c | 30 ------------------------------ utils/gssd/krb5_util.c | 3 +++ 7 files changed, 39 insertions(+), 33 deletions(-) create mode 100644 aclocal/libpthread.m4 -- 2.4.3 -- 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
