lockd: Fix server refcounting

The server shouldn't actually delete the struct nlm_host until it hits
the garbage collector. In order to make that work correctly with the
refcount API, we can bump the refcount by one, and then use
refcount_dec_if_one() in the garbage collector.

Signed-off-by: Trond Myklebust <trondmy@gmail.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 7d6ab72bbe65..d35cd6be0675 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -388,6 +388,8 @@ struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
         ln->nrhosts++;
         nrhosts++;
 
+        refcount_inc(&host->h_count);
+
         dprintk("lockd: %s created host %s (%s)\n",
                 __func__, host->h_name, host->h_addrbuf);
 
@@ -662,8 +664,7 @@ nlm_gc_hosts(struct net *net)
         for_each_host_safe(host, next, chain, nlm_server_hosts) {
                 if (net && host->net != net)
                         continue;
-                if (refcount_read(&host->h_count) || host->h_inuse
-                 || time_before(jiffies, host->h_expires)) {
+                if (host->h_inuse || time_before(jiffies, host->h_expires)) {
                         dprintk("nlm_gc_hosts skipping %s "
                                 "(cnt %d use %d exp %ld net %x)\n",
                                 host->h_name, refcount_read(&host->h_count),
@@ -671,7 +672,8 @@ nlm_gc_hosts(struct net *net)
                                 host->net->ns.inum);
                         continue;
                 }
-                nlm_destroy_host_locked(host);
+                if (refcount_dec_if_one(&host->h_count))
+                        nlm_destroy_host_locked(host);
         }
 
         if (net) {