protocol: add an option to force using old-protocol

As protocol implements every fop, and in general a large part of
the codebase. Considering our regression is run mostly in 1 machine,
there was no way of forcing the client to use old protocol (while new
one is available). With this patch, a new 'testing' option is provided
which forces client to use old protocol if found.

This should help increase the code coverage by at least 10k lines overall.

updates: bz#1693692
Change-Id: Ie45256f7dea250671b689c72b4b6f25037cef948
Signed-off-by: Amar Tumballi <amarts@redhat.com>

4 files changed, 55 insertions, 3 deletions

diff --git a/tests/basic/old-protocol.t b/tests/basic/old-protocol.t
new file mode 100755
index 00000000000..27a688d3538
--- /dev/null
+++ b/tests/basic/old-protocol.t
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+
+cleanup;
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume info;
+
+TEST $CLI volume create $V0 replica 3  $H0:$B0/${V0}{1,2,3,4,5,6};
+
+EXPECT "$V0" volinfo_field $V0 'Volume Name';
+EXPECT 'Created' volinfo_field $V0 'Status';
+EXPECT '6' brick_count $V0
+
+TEST $CLI volume start $V0;
+EXPECT 'Started' volinfo_field $V0 'Status';
+
+file="/var/lib/glusterd/vols/$V0/trusted-$V0.tcp-fuse.vol"
+sed -i -e 's$send-gids true$send-gids true\n    option testing.old-protocol true$g' $file
+
+## Mount FUSE
+TEST $GFS -s $H0 --volfile-id $V0 $M1;
+
+## TODO: best way to increase coverage is to have a gfapi program
+## which covers maximum fops
+TEST $(dirname $0)/rpc-coverage.sh $M1
+
+cleanup;
diff --git a/xlators/protocol/client/src/client-handshake.c b/xlators/protocol/client/src/client-handshake.c
index c43756a3fec..01505587243 100644
--- a/xlators/protocol/client/src/client-handshake.c
+++ b/xlators/protocol/client/src/client-handshake.c
@@ -1338,11 +1338,15 @@ select_server_supported_programs(xlator_t *this, gf_prog_detail *prog)
     while (trav) {
         /* Select 'programs' */
         if ((clnt3_3_fop_prog.prognum == trav->prognum) &&
-            (clnt3_3_fop_prog.progver == trav->progver) && !conf->fops) {
+            (clnt3_3_fop_prog.progver == trav->progver)) {
             conf->fops = &clnt3_3_fop_prog;
             if (conf->rpc)
                 conf->rpc->auth_value = AUTH_GLUSTERFS_v2;
             ret = 0;
+            /* In normal flow, we don't want to use old protocol type.
+               but if it is for testing, lets use it */
+            if (conf->old_protocol)
+                goto done;
         }
 
         if ((clnt4_0_fop_prog.prognum == trav->prognum) &&
@@ -1351,8 +1355,10 @@ select_server_supported_programs(xlator_t *this, gf_prog_detail *prog)
             if (conf->rpc)
                 conf->rpc->auth_value = AUTH_GLUSTERFS_v3;
             ret = 0;
-            /* this is latest program, lets use it */
-            goto out;
+            /* this is latest program, lets use this program only */
+            /* if we are testing for old-protocol, lets not break this */
+            if (!conf->old_protocol)
+                goto done;
         }
 
         if (ret) {
@@ -1362,6 +1368,7 @@ select_server_supported_programs(xlator_t *this, gf_prog_detail *prog)
         trav = trav->next;
     }
 
+done:
     if (!ret)
         gf_msg(this->name, GF_LOG_INFO, 0, PC_MSG_VERSION_INFO,
                "Using Program %s,"
diff --git a/xlators/protocol/client/src/client.c b/xlators/protocol/client/src/client.c
index 1e9f47297ee..fffe22380b1 100644
--- a/xlators/protocol/client/src/client.c
+++ b/xlators/protocol/client/src/client.c
@@ -2508,6 +2508,8 @@ build_client_config(xlator_t *this, clnt_conf_t *conf)
 
     GF_OPTION_INIT("send-gids", conf->send_gids, bool, out);
 
+    GF_OPTION_INIT("testing.old-protocol", conf->old_protocol, bool, out);
+
     conf->client_id = glusterfs_leaf_position(this);
 
     ret = client_check_remote_host(this, this->options);
@@ -3048,6 +3050,16 @@ struct volume_options options[] = {
                     " power. Range 1-32 threads.",
      .op_version = {GD_OP_VERSION_3_7_0},
      .flags = OPT_FLAG_SETTABLE | OPT_FLAG_DOC},
+
+    /* This option is required for running code-coverage tests with
+       old protocol */
+    {
+        .key = {"testing.old-protocol"},
+        .type = GF_OPTION_TYPE_BOOL,
+        .default_value = "off",
+        .op_version = {GD_OP_VERSION_7_0},
+        .flags = OPT_FLAG_SETTABLE,
+    },
     {.key = {NULL}},
 };
 
diff --git a/xlators/protocol/client/src/client.h b/xlators/protocol/client/src/client.h
index f12fa61bb93..60efa9c264a 100644
--- a/xlators/protocol/client/src/client.h
+++ b/xlators/protocol/client/src/client.h
@@ -235,6 +235,8 @@ typedef struct clnt_conf {
                                       * up, disconnects can be
                                       * logged
                                       */
+
+    gf_boolean_t old_protocol; /* used only for old-protocol testing */
 } clnt_conf_t;
 
 typedef struct _client_fd_ctx {