afs: Probe multiple fileservers simultaneously

[linux.git] / fs / afs / server.c

diff --git a/fs/afs/server.c b/fs/afs/server.c
index 7c1be8b4dc9a2d5bd2efdeee94c3e621c9258b0a..642afa2e9783c4f95284980dd8054610fa4d49cf 100644 (file)
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -231,6 +231,8 @@ static struct afs_server *afs_alloc_server(struct afs_net *net,
        rwlock_init(&server->fs_lock);
        INIT_HLIST_HEAD(&server->cb_volumes);
        rwlock_init(&server->cb_break_lock);
+       init_waitqueue_head(&server->probe_wq);
+       spin_lock_init(&server->probe_lock);
 
        afs_inc_servers_outstanding(net);
        _leave(" = %p", server);
@@ -254,7 +256,7 @@ static struct afs_addr_list *afs_vl_lookup_addrs(struct afs_cell *cell,
        ret = -ERESTARTSYS;
        if (afs_begin_vlserver_operation(&vc, cell, key)) {
                while (afs_select_vlserver(&vc)) {
-                       if (test_bit(vc.ac.index, &vc.ac.alist->yfs))
+                       if (test_bit(AFS_VLSERVER_FL_IS_YFS, &vc.server->flags))
                                alist = afs_yfsvl_get_endpoints(&vc, uuid);
                        else
                                alist = afs_vl_get_addrs_u(&vc, uuid);
@@ -365,8 +367,7 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
        struct afs_addr_list *alist = rcu_access_pointer(server->addresses);
        struct afs_addr_cursor ac = {
                .alist  = alist,
-               .start  = alist->index,
-               .index  = 0,
+               .index  = alist->preferred,
                .error  = 0,
        };
        _enter("%p", server);
@@ -374,6 +375,9 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
        if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags))
                afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
 
+       wait_var_event(&server->probe_outstanding,
+                      atomic_read(&server->probe_outstanding) == 0);
+
        call_rcu(&server->rcu, afs_server_rcu);
        afs_dec_servers_outstanding(net);
 }
@@ -506,105 +510,6 @@ void afs_purge_servers(struct afs_net *net)
        _leave("");
 }
 
-/*
- * Probe a fileserver to find its capabilities.
- *
- * TODO: Try service upgrade.
- */
-static bool afs_do_probe_fileserver(struct afs_fs_cursor *fc)
-{
-       int i;
-
-       _enter("");
-
-       fc->ac.start = READ_ONCE(fc->ac.alist->index);
-       fc->ac.index = fc->ac.start;
-       fc->ac.error = 0;
-       fc->ac.begun = false;
-
-       while (afs_iterate_addresses(&fc->ac)) {
-               afs_fs_get_capabilities(afs_v2net(fc->vnode), fc->cbi->server,
-                                       &fc->ac, fc->key);
-               switch (fc->ac.error) {
-               case 0:
-                       if (test_bit(AFS_SERVER_FL_IS_YFS, &fc->cbi->server->flags)) {
-                               for (i = 0; i < fc->ac.alist->nr_addrs; i++)
-                                       fc->ac.alist->addrs[i].srx_service =
-                                               YFS_FS_SERVICE;
-                       }
-                       afs_end_cursor(&fc->ac);
-                       set_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags);
-                       return true;
-               case -ECONNABORTED:
-                       fc->ac.error = afs_abort_to_error(fc->ac.abort_code);
-                       goto error;
-               case -ENOMEM:
-               case -ENONET:
-                       goto error;
-               case -ENETUNREACH:
-               case -EHOSTUNREACH:
-               case -ECONNREFUSED:
-               case -ETIMEDOUT:
-               case -ETIME:
-                       break;
-               default:
-                       fc->ac.error = afs_io_error(NULL, afs_io_error_fs_probe_fail);
-                       goto error;
-               }
-       }
-
-error:
-       afs_end_cursor(&fc->ac);
-       return false;
-}
-
-/*
- * If we haven't already, try probing the fileserver to get its capabilities.
- * We try not to instigate parallel probes, but it's possible that the parallel
- * probes will fail due to authentication failure when ours would succeed.
- *
- * TODO: Try sending an anonymous probe if an authenticated probe fails.
- */
-bool afs_probe_fileserver(struct afs_fs_cursor *fc)
-{
-       bool success;
-       int ret, retries = 0;
-
-       _enter("");
-
-retry:
-       if (test_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags)) {
-               _leave(" = t");
-               return true;
-       }
-
-       if (!test_and_set_bit_lock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags)) {
-               success = afs_do_probe_fileserver(fc);
-               clear_bit_unlock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags);
-               wake_up_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING);
-               _leave(" = t");
-               return success;
-       }
-
-       _debug("wait");
-       ret = wait_on_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING,
-                         TASK_INTERRUPTIBLE);
-       if (ret == -ERESTARTSYS) {
-               fc->ac.error = ret;
-               _leave(" = f [%d]", ret);
-               return false;
-       }
-
-       retries++;
-       if (retries == 4) {
-               fc->ac.error = -ESTALE;
-               _leave(" = f [stale]");
-               return false;
-       }
-       _debug("retry");
-       goto retry;
-}
-
 /*
  * Get an update for a server's address list.
  */