[PATCH] knfsd: Correctly handle error condition from lockd_up

If lockd_up fails - what should we expect?  Do we have to later call
lockd_down?

Well the nfs client thinks "no", the nfs server thinks "yes".  lockd thinks
"yes".

The only answer that really makes sense is "no" !!

So:
  Make lockd_up only increment  nlmsvc_users on success.
  Make nfsd handle errors from lockd_up properly.
  Make sure lockd_up(0) never fails when lockd is running
    so that the 'reclaimer' call to lockd_up doesn't need to
    be error checked.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 16 insertions, 14 deletions

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index 6abb465b650f..87e1d03e8267 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -202,7 +202,7 @@ reclaimer(void *ptr)
         /* This one ensures that our parent doesn't terminate while the
          * reclaim is in progress */
         lock_kernel();
-        lockd_up(0);
+        lockd_up(0); /* note: this cannot fail as lockd is already running */
 
         nlmclnt_prepare_reclaim(host);
         /* First, reclaim all locks that have been marked. */
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 448768b52913..3cc369e5693f 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -254,15 +254,11 @@ lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 
         mutex_lock(&nlmsvc_mutex);
         /*
-         * Unconditionally increment the user count ... this is
-         * the number of clients who _want_ a lockd process.
-         */
-        nlmsvc_users++; 
-        /*
          * Check whether we're already up and running.
          */
         if (nlmsvc_pid) {
-                error = make_socks(nlmsvc_serv, proto);
+                if (proto)
+                        error = make_socks(nlmsvc_serv, proto);
                 goto out;
         }
 
@@ -270,7 +266,7 @@ lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
          * Sanity check: if there's no pid,
          * we should be the first user ...
          */
-        if (nlmsvc_users > 1)
+        if (nlmsvc_users)
                 printk(KERN_WARNING
                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 
@@ -302,6 +298,8 @@ lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 destroy_and_out:
         svc_destroy(serv);
 out:
+        if (!error)
+                nlmsvc_users++;
         mutex_unlock(&nlmsvc_mutex);
         return error;
 }
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index f1314c63e823..cdec3993e0d5 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -221,18 +221,22 @@ static int nfsd_init_socks(int port)
         if (!list_empty(&nfsd_serv->sv_permsocks))
                 return 0;
 
-        error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
-        if (error < 0)
-                return error;
         error = lockd_up(IPPROTO_UDP);
+        if (error >= 0) {
+                error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
+                if (error < 0)
+                        lockd_down();
+        }
         if (error < 0)
                 return error;
 
 #ifdef CONFIG_NFSD_TCP
-        error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
-        if (error < 0)
-                return error;
         error = lockd_up(IPPROTO_TCP);
+        if (error >= 0) {
+                error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
+                if (error < 0)
+                        lockd_down();
+        }
         if (error < 0)
                 return error;
 #endif