nfsd4: fix v4 state shutdown error paths
If someone tries to shut down the laundry_wq while it isn't up it'll
cause an oops.
This can happen because write_ports can create a nfsd_svc before we
really start the nfs server, and we may fail before the server is ever
started.
Also make sure state is shutdown on error paths in nfsd_svc().
Use a common global nfsd_up flag instead of nfs4_init, and create common
helper functions for nfsd start/shutdown, as there will be other work
that we want done only when we the number of nfsd threads transitions
between zero and nonzero.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 06b2a26..d7a4d7b 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -180,6 +180,31 @@
return rv;
}
+static bool nfsd_up = false;
+
+static int nfsd_startup(unsigned short port, int nrservs)
+{
+ int ret;
+
+ ret = nfs4_state_start();
+ nfsd_up = true;
+ return ret;
+}
+
+static void nfsd_shutdown(void)
+{
+ /*
+ * write_ports can create the server without actually starting
+ * any threads--if we get shut down before any threads are
+ * started, then nfsd_last_thread will be run before any of this
+ * other initialization has been done.
+ */
+ if (!nfsd_up)
+ return;
+ nfs4_state_shutdown();
+ nfsd_up = false;
+}
+
static void nfsd_last_thread(struct svc_serv *serv)
{
/* When last nfsd thread exits we need to do some clean-up */
@@ -188,7 +213,7 @@
lockd_down();
nfsd_serv = NULL;
nfsd_racache_shutdown();
- nfs4_state_shutdown();
+ nfsd_shutdown();
printk(KERN_WARNING "nfsd: last server has exited, flushing export "
"cache\n");
@@ -380,6 +405,7 @@
nfsd_svc(unsigned short port, int nrservs)
{
int error;
+ bool first_thread;
mutex_lock(&nfsd_mutex);
dprintk("nfsd: creating service\n");
@@ -395,19 +421,23 @@
error = nfsd_racache_init(2*nrservs);
if (error<0)
goto out;
- error = nfs4_state_start();
- if (error)
- goto out;
+
+ first_thread = (nfsd_serv->sv_nrthreads == 0) && (nrservs != 0);
+
+ if (first_thread) {
+ error = nfsd_startup(port, nrservs);
+ if (error)
+ goto out;
+ }
nfsd_reset_versions();
error = nfsd_create_serv();
-
if (error)
- goto out;
+ goto out_shutdown;
error = nfsd_init_socks(port);
if (error)
- goto failure;
+ goto out_destroy;
error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
if (error == 0)
@@ -416,9 +446,12 @@
* so subtract 1
*/
error = nfsd_serv->sv_nrthreads - 1;
- failure:
+out_destroy:
svc_destroy(nfsd_serv); /* Release server */
- out:
+out_shutdown:
+ if (error < 0 && first_thread)
+ nfsd_shutdown();
+out:
mutex_unlock(&nfsd_mutex);
return error;
}