SUNRPC: create unix gid cache per network namespace

v2:
1) fixed silly usage of template cache as a real one (this code left from
static global cache for all)

This patch makes unix_gid_cache cache detail allocated and registered per
network namespace context.
Thus with this patch unix_gid_cache contents for network namespace "X" are
controlled from proc file system mount for the same network namespace "X".

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 41 insertions, 14 deletions

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 2f8c426c1384..a6eef38fb35c 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -436,7 +436,6 @@ struct unix_gid {
         uid_t                   uid;
         struct group_info       *gi;
 };
-static struct cache_head        *gid_table[GID_HASHMAX];
 
 static void unix_gid_put(struct kref *kref)
 {
@@ -494,8 +493,7 @@ static int unix_gid_upcall(struct cache_detail *cd, struct cache_head *h)
         return sunrpc_cache_pipe_upcall(cd, h, unix_gid_request);
 }
 
-static struct unix_gid *unix_gid_lookup(uid_t uid);
-extern struct cache_detail unix_gid_cache;
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, uid_t uid);
 
 static int unix_gid_parse(struct cache_detail *cd,
                         char *mesg, int mlen)
@@ -539,19 +537,19 @@ static int unix_gid_parse(struct cache_detail *cd,
                 GROUP_AT(ug.gi, i) = gid;
         }
 
-        ugp = unix_gid_lookup(uid);
+        ugp = unix_gid_lookup(cd, uid);
         if (ugp) {
                 struct cache_head *ch;
                 ug.h.flags = 0;
                 ug.h.expiry_time = expiry;
-                ch = sunrpc_cache_update(&unix_gid_cache,
+                ch = sunrpc_cache_update(cd,
                                          &ug.h, &ugp->h,
                                          hash_long(uid, GID_HASHBITS));
                 if (!ch)
                         err = -ENOMEM;
                 else {
                         err = 0;
-                        cache_put(ch, &unix_gid_cache);
+                        cache_put(ch, cd);
                 }
         } else
                 err = -ENOMEM;
@@ -587,10 +585,9 @@ static int unix_gid_show(struct seq_file *m,
         return 0;
 }
 
-struct cache_detail unix_gid_cache = {
+static struct cache_detail unix_gid_cache_template = {
         .owner          = THIS_MODULE,
         .hash_size      = GID_HASHMAX,
-        .hash_table     = gid_table,
         .name           = "auth.unix.gid",
         .cache_put      = unix_gid_put,
         .cache_upcall   = unix_gid_upcall,
@@ -602,14 +599,42 @@ struct cache_detail unix_gid_cache = {
         .alloc          = unix_gid_alloc,
 };
 
-static struct unix_gid *unix_gid_lookup(uid_t uid)
+int unix_gid_cache_create(struct net *net)
+{
+        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+        struct cache_detail *cd;
+        int err;
+
+        cd = cache_create_net(&unix_gid_cache_template, net);
+        if (IS_ERR(cd))
+                return PTR_ERR(cd);
+        err = cache_register_net(cd, net);
+        if (err) {
+                cache_destroy_net(cd, net);
+                return err;
+        }
+        sn->unix_gid_cache = cd;
+        return 0;
+}
+
+void unix_gid_cache_destroy(struct net *net)
+{
+        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+        struct cache_detail *cd = sn->unix_gid_cache;
+
+        sn->unix_gid_cache = NULL;
+        cache_purge(cd);
+        cache_unregister_net(cd, net);
+        cache_destroy_net(cd, net);
+}
+
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, uid_t uid)
 {
         struct unix_gid ug;
         struct cache_head *ch;
 
         ug.uid = uid;
-        ch = sunrpc_cache_lookup(&unix_gid_cache, &ug.h,
-                                 hash_long(uid, GID_HASHBITS));
+        ch = sunrpc_cache_lookup(cd, &ug.h, hash_long(uid, GID_HASHBITS));
         if (ch)
                 return container_of(ch, struct unix_gid, h);
         else
@@ -621,11 +646,13 @@ static struct group_info *unix_gid_find(uid_t uid, struct svc_rqst *rqstp)
         struct unix_gid *ug;
         struct group_info *gi;
         int ret;
+        struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net,
+                                            sunrpc_net_id);
 
-        ug = unix_gid_lookup(uid);
+        ug = unix_gid_lookup(sn->unix_gid_cache, uid);
         if (!ug)
                 return ERR_PTR(-EAGAIN);
-        ret = cache_check(&unix_gid_cache, &ug->h, &rqstp->rq_chandle);
+        ret = cache_check(sn->unix_gid_cache, &ug->h, &rqstp->rq_chandle);
         switch (ret) {
         case -ENOENT:
                 return ERR_PTR(-ENOENT);
@@ -633,7 +660,7 @@ static struct group_info *unix_gid_find(uid_t uid, struct svc_rqst *rqstp)
                 return ERR_PTR(-ESHUTDOWN);
         case 0:
                 gi = get_group_info(ug->gi);
-                cache_put(&ug->h, &unix_gid_cache);
+                cache_put(&ug->h, sn->unix_gid_cache);
                 return gi;
         default:
                 return ERR_PTR(-EAGAIN);