On Thu, 18 Jan 2017, Kinglong Mee wrote: > Commit bb6aeba736ba "NFSv4.x: Switch to using svc_set_num_threads() > to manage the callback threads" change nfs start/stop threads > through svc_set_num_threads(). > > It destroy old threads by SIGINT signal, but our nfs4_callback_svc() > isn't interruptible. So that, the callback threads will never be killed. > > # mount -t nfs -overs=4.2 nfstestnic:/ /mnt/ > # ps -ajx |grep NFS > 2 5927 0 0 ? -1 S 0 0:00 [NFSv4 callback] > # umount /mnt > # ps -ajx |grep NFS > 2 5927 0 0 ? -1 S 0 0:00 [NFSv4 callback] > # mount -t nfs -overs=4.2 nfstestnic:/ /mnt/ > # umount /mnt > # ps -ajx |grep NFS > 2 5927 0 0 ? -1 S 0 0:00 [NFSv4 callback] > 2 5963 0 0 ? -1 S 0 0:00 [NFSv4 callback] > > After one mount, there will be one callback thread left that cannot killed, > the same time, nfs.ko will never be unplugged. > > v2, drop the wrong setting of rqstp->rq_server = NULL > > Signed-off-by: Kinglong Mee <kinglongmee@xxxxxxxxx> Thanks! We have some fedora users complaining about this problem: https://bugzilla.redhat.com/show_bug.cgi?id=1427493 This and [PATCH v2 1/2] NFSv4.x/callback: Create the callback service through svc_create_pooled fix it up for me. Reviewed-by: Benjamin Coddington <bcodding@xxxxxxxxxx> Tested-by: Benjamin Coddington <bcodding@xxxxxxxxxx> Ben > --- > fs/nfs/callback.c | 39 +++++++++++++++++++++++++++++++++++---- > 1 file changed, 35 insertions(+), 4 deletions(-) > > diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c > index 0a21150..2a0fffd 100644 > --- a/fs/nfs/callback.c > +++ b/fs/nfs/callback.c > @@ -73,6 +73,15 @@ nfs4_callback_svc(void *vrqstp) > int err; > struct svc_rqst *rqstp = vrqstp; > > + /* > + * thread is spawned with all signals set to SIG_IGN, re-enable > + * the ones that will bring down the thread > + */ > + allow_signal(SIGKILL); > + allow_signal(SIGHUP); > + allow_signal(SIGINT); > + allow_signal(SIGQUIT); > + > set_freezable(); > > while (!kthread_should_stop()) { > @@ -80,11 +89,18 @@ nfs4_callback_svc(void *vrqstp) > * Listen for a request on the socket > */ > err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); > - if (err == -EAGAIN || err == -EINTR) > + if (err == -EAGAIN) > continue; > + else if (err == -EINTR) > + break; > svc_process(rqstp); > } > - return 0; > + > + flush_signals(current); > + > + /* Release the thread */ > + svc_exit_thread(rqstp); > + module_put_and_exit(0); > } > > #if defined(CONFIG_NFS_V4_1) > @@ -100,6 +116,15 @@ nfs41_callback_svc(void *vrqstp) > int error; > DEFINE_WAIT(wq); > > + /* > + * thread is spawned with all signals set to SIG_IGN, re-enable > + * the ones that will bring down the thread > + */ > + allow_signal(SIGKILL); > + allow_signal(SIGHUP); > + allow_signal(SIGINT); > + allow_signal(SIGQUIT); > + > set_freezable(); > > while (!kthread_should_stop()) { > @@ -121,11 +146,17 @@ nfs41_callback_svc(void *vrqstp) > } else { > spin_unlock_bh(&serv->sv_cb_lock); > schedule(); > + if (signalled()) > + break; > finish_wait(&serv->sv_cb_waitq, &wq); > } > - flush_signals(current); > } > - return 0; > + > + flush_signals(current); > + > + /* Release the thread */ > + svc_exit_thread(rqstp); > + module_put_and_exit(0); > } > > static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, > -- > 2.9.3 > > -- > 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 > -- 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
