nfsd: just keep single lockd reference for nfsd

Right now, nfsd keeps a lockd reference for each socket that it has
open. This is unnecessary and complicates the error handling on
startup and shutdown. Change it to just do a lockd_up when starting
the first nfsd thread just do a single lockd_down when taking down the
last nfsd thread. Because of the strange way the sv_count is handled
this requires an extra flag to tell whether the nfsd_serv holds a
reference for lockd or not.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

2 files changed, 14 insertions, 21 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 9e8645a07fca..b1c5be85bea5 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -949,15 +949,8 @@ static ssize_t __write_ports_addfd(char *buf)
         if (err != 0)
                 return err;
 
-        err = lockd_up();
-        if (err != 0) {
-                svc_destroy(nfsd_serv);
-                return err;
-        }
-
         err = svc_addsock(nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT);
         if (err < 0) {
-                lockd_down();
                 svc_destroy(nfsd_serv);
                 return err;
         }
@@ -982,9 +975,6 @@ static ssize_t __write_ports_delfd(char *buf)
         if (nfsd_serv != NULL)
                 len = svc_sock_names(nfsd_serv, buf,
                                         SIMPLE_TRANSACTION_LIMIT, toclose);
-        if (len >= 0)
-                lockd_down();
-
         kfree(toclose);
         return len;
 }
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index a631ea61f76a..8a556ff2e10d 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -186,8 +186,16 @@ static int nfsd_startup(unsigned short port, int nrservs)
 {
         int ret;
 
+        ret = lockd_up();
+        if (ret)
+                return ret;
         ret = nfs4_state_start();
+        if (ret)
+                goto out_lockd;
         nfsd_up = true;
+        return 0;
+out_lockd:
+        lockd_down();
         return ret;
 }
 
@@ -201,6 +209,7 @@ static void nfsd_shutdown(void)
          */
         if (!nfsd_up)
                 return;
+        lockd_down();
         nfs4_state_shutdown();
         nfsd_up = false;
 }
@@ -208,9 +217,6 @@ static void nfsd_shutdown(void)
 static void nfsd_last_thread(struct svc_serv *serv)
 {
         /* When last nfsd thread exits we need to do some clean-up */
-        struct svc_xprt *xprt;
-        list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list)
-                lockd_down();
         nfsd_serv = NULL;
         nfsd_racache_shutdown();
         nfsd_shutdown();
@@ -310,19 +316,11 @@ static int nfsd_init_socks(int port)
         if (error < 0)
                 return error;
 
-        error = lockd_up();
-        if (error < 0)
-                return error;
-
         error = svc_create_xprt(nfsd_serv, "tcp", PF_INET, port,
                                         SVC_SOCK_DEFAULTS);
         if (error < 0)
                 return error;
 
-        error = lockd_up();
-        if (error < 0)
-                return error;
-
         return 0;
 }
 
@@ -400,6 +398,11 @@ int nfsd_set_nrthreads(int n, int *nthreads)
         return err;
 }
 
+/*
+ * Adjust the number of threads and return the new number of threads.
+ * This is also the function that starts the server if necessary, if
+ * this is the first time nrservs is nonzero.
+ */
 int
 nfsd_svc(unsigned short port, int nrservs)
 {