afs: Fix afs_cell records to always have a VL server list record

Fix it such that afs_cell records always have a VL server list record
attached, even if it's a dummy one, so that various checks can be removed.

Signed-off-by: David Howells <dhowells@redhat.com>

4 files changed, 25 insertions, 24 deletions

diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 9ca075e11239..47f96be05163 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -123,6 +123,7 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
                                        const char *name, unsigned int namelen,
                                        const char *addresses)
 {
+        struct afs_vlserver_list *vllist;
         struct afs_cell *cell;
         int i, ret;
 
@@ -157,12 +158,10 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
         rwlock_init(&cell->proc_lock);
         rwlock_init(&cell->vl_servers_lock);
 
-        /* Fill in the VL server list if we were given a list of addresses to
-         * use.
+        /* Provide a VL server list, filling it in if we were given a list of
+         * addresses to use.
          */
         if (addresses) {
-                struct afs_vlserver_list *vllist;
-
                 vllist = afs_parse_text_addrs(net,
                                               addresses, strlen(addresses), ':',
                                               VL_SERVICE, AFS_VL_PORT);
@@ -171,19 +170,24 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
                         goto parse_failed;
                 }
 
-                rcu_assign_pointer(cell->vl_servers, vllist);
                 cell->dns_expiry = TIME64_MAX;
-                __clear_bit(AFS_CELL_FL_NO_LOOKUP_YET, &cell->flags);
         } else {
+                ret = -ENOMEM;
+                vllist = afs_alloc_vlserver_list(0);
+                if (!vllist)
+                        goto error;
                 cell->dns_expiry = ktime_get_real_seconds();
         }
 
+        rcu_assign_pointer(cell->vl_servers, vllist);
+
         _leave(" = %p", cell);
         return cell;
 
 parse_failed:
         if (ret == -EINVAL)
                 printk(KERN_ERR "kAFS: bad VL server IP address\n");
+error:
         kfree(cell);
         _leave(" = %d", ret);
         return ERR_PTR(ret);
@@ -410,8 +414,7 @@ static void afs_update_cell(struct afs_cell *cell)
                 cell->dns_expiry = expiry;
                 write_unlock(&cell->vl_servers_lock);
 
-                if (old)
-                        afs_put_vlserverlist(cell->net, old);
+                afs_put_vlserverlist(cell->net, old);
         }
 
         if (test_and_clear_bit(AFS_CELL_FL_NO_LOOKUP_YET, &cell->flags))
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index be2ee3bbd0a9..371501d28e08 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -53,7 +53,7 @@ static int afs_proc_cells_show(struct seq_file *m, void *v)
         seq_printf(m, "%3u %6lld %2u %s\n",
                    atomic_read(&cell->usage),
                    cell->dns_expiry - ktime_get_real_seconds(),
-                   vllist ? vllist->nr_servers : 0,
+                   vllist->nr_servers,
                    cell->name);
         return 0;
 }
@@ -296,8 +296,8 @@ static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
 
         if (v == SEQ_START_TOKEN) {
                 seq_printf(m, "# source %s, status %s\n",
-                           dns_record_sources[vllist->source],
-                           dns_lookup_statuses[vllist->status]);
+                           dns_record_sources[vllist ? vllist->source : 0],
+                           dns_lookup_statuses[vllist ? vllist->status : 0]);
                 return 0;
         }
 
@@ -336,7 +336,7 @@ static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
         if (pos == 0)
                 return SEQ_START_TOKEN;
 
-        if (!vllist || pos - 1 >= vllist->nr_servers)
+        if (pos - 1 >= vllist->nr_servers)
                 return NULL;
 
         return &vllist->servers[pos - 1];
diff --git a/fs/afs/vl_list.c b/fs/afs/vl_list.c
index b4f1a84519b9..61e25010ff33 100644
--- a/fs/afs/vl_list.c
+++ b/fs/afs/vl_list.c
@@ -232,18 +232,16 @@ struct afs_vlserver_list *afs_extract_vlserver_list(struct afs_cell *cell,
                 if (bs.status > NR__dns_lookup_status)
                         bs.status = NR__dns_lookup_status;
 
+                /* See if we can update an old server record */
                 server = NULL;
-                if (previous) {
-                        /* See if we can update an old server record */
-                        for (i = 0; i < previous->nr_servers; i++) {
-                                struct afs_vlserver *p = previous->servers[i].server;
-
-                                if (p->name_len == bs.name_len &&
-                                    p->port == bs.port &&
-                                    strncasecmp(b, p->name, bs.name_len) == 0) {
-                                        server = afs_get_vlserver(p);
-                                        break;
-                                }
+                for (i = 0; i < previous->nr_servers; i++) {
+                        struct afs_vlserver *p = previous->servers[i].server;
+
+                        if (p->name_len == bs.name_len &&
+                            p->port == bs.port &&
+                            strncasecmp(b, p->name, bs.name_len) == 0) {
+                                server = afs_get_vlserver(p);
+                                break;
                         }
                 }
 
diff --git a/fs/afs/vl_rotate.c b/fs/afs/vl_rotate.c
index 7adde83a0648..65629d73ad9d 100644
--- a/fs/afs/vl_rotate.c
+++ b/fs/afs/vl_rotate.c
@@ -55,7 +55,7 @@ static bool afs_start_vl_iteration(struct afs_vl_cursor *vc)
                 rcu_dereference_protected(cell->vl_servers,
                                           lockdep_is_held(&cell->vl_servers_lock)));
         read_unlock(&cell->vl_servers_lock);
-        if (!vc->server_list || !vc->server_list->nr_servers)
+        if (!vc->server_list->nr_servers)
                 return false;
 
         vc->untried = (1UL << vc->server_list->nr_servers) - 1;