Hi there, On 20/08/25 3:08 AM, NeilBrown wrote: > rpc_wait_bit_killable() is called when it is appropriate for a fatal > signal to abort the wait. > > If it is called late during process exit after exit_signals() is called > (and when PF_EXITING is set), it cannot receive a fatal signal so > waiting indefinitely is not safe. > > However aborting immediately, as it currently does, is not ideal as it > mean that the related NFS request cannot succeed, even if the network > and server are working properly. > > One of the causes of filesystem IO when PF_EXITING is set is > acct_process() which may access the process accounting file. For a > NFS-root configuration, this can be accessed over NFS. > > In this configuration LTP test "acct02" fails. > > Though waiting indefinitely is not appropriate, aborting immediately is > also not desirable. This patch aims for a middle ground of waiting at > most 5 seconds. This should be enough when NFS service is working, but > not so much as to delay process exit excessively when NFS service is not > functioning. > > Reported-by: Mark Brown <broonie@xxxxxxxxxx> > Reported-and-tested-by: Harshvardhan Jha <harshvardhan.j.jha@xxxxxxxxxx> > Link: https://urldefense.com/v3/__https://lore.kernel.org/linux-nfs/7d4d57b0-39a3-49f1-8ada-60364743e3b4@xxxxxxxxxxxxx/__;!!ACWV5N9M2RV99hQ!LaRJdjZulcG71nHFWdEAszB9mJEhezxPsDxHO8xeQJ7P8a9UfYNRIm1ziuuHU5wxgEXW14vAqC1dlpSQraWaxA$ > Fixes: 14e41b16e8cb ("SUNRPC: Don't allow waiting for exiting tasks") > Signed-off-by: NeilBrown <neil@xxxxxxxxxx> > --- > net/sunrpc/sched.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c > index 73bc39281ef5..92f39e828fbe 100644 > --- a/net/sunrpc/sched.c > +++ b/net/sunrpc/sched.c > @@ -276,11 +276,15 @@ EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue); > > static int rpc_wait_bit_killable(struct wait_bit_key *key, int mode) > { > - if (unlikely(current->flags & PF_EXITING)) > - return -EINTR; > - schedule(); > - if (signal_pending_state(mode, current)) > - return -ERESTARTSYS; > + if (unlikely(current->flags & PF_EXITING)) { > + /* Cannot be killed by a signal, so don't wait indefinitely */ > + if (schedule_timeout(5 * HZ) == 0) > + return -EINTR; > + } else { > + schedule(); > + if (signal_pending_state(mode, current)) > + return -ERESTARTSYS; > + } > return 0; > } > Is it possible to get this merged in 6.17? I have tested this and the LTP tests pass. Thanks & Regards, Harshvardhan
