features/shard: Introducing sharding translator

Based on the high-level design by Anand V. Avati which can be found @
https://gist.github.com/avati/af04f1030dcf52e16535#sharding-xlator-stripe-20

Still to-do:
        * complete implementation of inode write fops - [f]truncate,
          zerofill, fallocate, discard
        * introduce transaction mechanism in inode write fops
        * complete readv
        * Handle open with O_TRUNC
        * Handle unlinking of all shards during unlink/rename
        * Compute total ia_size and ia_blocks in lookup, readdirp, etc
        * wind fsync/flush on all shards

        Note: Most of the items above are related. Once we come up
        with a clean way to determine the last shard/shard count for
        a file/file size and the mgmt of sparse regions of the file,
        implementing them becomes trivial.

Change-Id: Id871379b53a4a916e4baa2e06f197dd8c0043b0f
BUG: 1200082
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/9841
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-set.c b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
index ada814bb25d..68e3fb7d46b 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-set.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
@@ -1763,6 +1763,17 @@ struct volopt_map_entry glusterd_volopt_map[] = {
           .type        = NO_DOC,
           .op_version  = GD_OP_VERSION_3_7_0,
         },
+        { .key        = "features.shard",
+          .voltype    = "features/shard",
+          .value      = "off",
+          .op_version = GD_OP_VERSION_3_7_0,
+          .flags      = OPT_FLAG_CLIENT_OPT
+        },
+        { .key        = "features.shard-block-size",
+          .voltype    = "features/shard",
+          .op_version = GD_OP_VERSION_3_7_0,
+          .flags      = OPT_FLAG_CLIENT_OPT
+        },
         { .key         = NULL
         }
 };