quick-read: rename cache-invalidation key to avoid redundant keys

With group-metadata-cache group profile settings
performance.cache-invalidation option when turned on enables both md-cache
and quick-read xlator's cache-invalidation feature. While the intent of
the group-metadata-cache is to set md-cache xlator's cache-invalidation
feature, quick-read xlator also gets affected due to the same. While
md-cache feature and it's profile existed since release-3.9,
quick-read cache-invalidation was introduced in release-4 and due to
this op-version mismatch on any cluster which is >= glusterfs-4 when
this group profile is applied it breaks backward compatibility with the
old clients.

The proposed fix here is to rename the key in quick-read to
'quick-read-cache-invalidation' so that both these features have
distinct identification. While this brings in by itself a backward
compatibility challenge where this feature is enabled in an existing
cluster and when the same is upgraded to a version where this change
exists, it will lead to an unidentified old key. But as a workaround we
can always ask users upgrading to release-7 version to turn off this
option, upgrade the cluster and turn it back on with the new key. This
needs to be documented once the patch is accepted.

Fixes: bz#1698042
Change-Id: I30422ba6496208e21191a8d78ad29b2e21078664
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
Signed-off-by: Raghavendra G <rgowdapp@redhat.com>

2 files changed, 7 insertions, 6 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-set.c b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
index b943f66c008..4cadcd5dd19 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-set.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
@@ -1251,9 +1251,9 @@ struct volopt_map_entry glusterd_volopt_map[] = {
      .option = "cache-timeout",
      .op_version = 1,
      .flags = VOLOPT_FLAG_CLIENT_OPT},
-    {.key = "performance.cache-invalidation",
+    {.key = "performance.quick-read-cache-invalidation",
      .voltype = "performance/quick-read",
-     .option = "cache-invalidation",
+     .option = "quick-read-cache-invalidation",
      .op_version = GD_OP_VERSION_4_0_0,
      .flags = VOLOPT_FLAG_CLIENT_OPT},
     {.key = "performance.ctime-invalidation",
diff --git a/xlators/performance/quick-read/src/quick-read.c b/xlators/performance/quick-read/src/quick-read.c
index 244e8c8d44e..4f16d148262 100644
--- a/xlators/performance/quick-read/src/quick-read.c
+++ b/xlators/performance/quick-read/src/quick-read.c
@@ -1218,8 +1218,8 @@ qr_reconfigure(xlator_t *this, dict_t *options)
 
     GF_OPTION_RECONF("cache-timeout", conf->cache_timeout, options, int32, out);
 
-    GF_OPTION_RECONF("cache-invalidation", conf->qr_invalidation, options, bool,
-                     out);
+    GF_OPTION_RECONF("quick-read-cache-invalidation", conf->qr_invalidation,
+                     options, bool, out);
 
     GF_OPTION_RECONF("ctime-invalidation", conf->ctime_invalidation, options,
                      bool, out);
@@ -1369,7 +1369,8 @@ qr_init(xlator_t *this)
 
     GF_OPTION_INIT("cache-timeout", conf->cache_timeout, int32, out);
 
-    GF_OPTION_INIT("cache-invalidation", conf->qr_invalidation, bool, out);
+    GF_OPTION_INIT("quick-read-cache-invalidation", conf->qr_invalidation, bool,
+                   out);
 
     GF_OPTION_INIT("cache-size", conf->cache_size, size_uint64, out);
     if (!check_cache_size_ok(this, conf->cache_size)) {
@@ -1615,7 +1616,7 @@ struct volume_options qr_options[] = {
         .flags = OPT_FLAG_CLIENT_OPT | OPT_FLAG_SETTABLE | OPT_FLAG_DOC,
     },
     {
-        .key = {"cache-invalidation"},
+        .key = {"quick-read-cache-invalidation"},
         .type = GF_OPTION_TYPE_BOOL,
         .default_value = "false",
         .op_version = {GD_OP_VERSION_4_0_0},