dht/rebalancer: Marking tiering migration fops

This is a follow up patch for http://review.gluster.org/#/c/10080
In the above, the suggested change in
http://review.gluster.org/#/c/10080/7/xlators/cluster/dht/src/dht-rebalance.c
doesnot work. The reason it doesnt work is promotion and demotion are done in
a multithread way. Whenever a promotion or demotion thread is called, the frame
of the old sync_op thread is not carried with it. As a result the frame->root->pid
is not set.

Solution:
When the file is getting migrated, we get a tiering.migration key_value in the
xattr dict, so that we pass  this dic key-value when we do syncop_setxattr()
to do  data migration and set the frame->root->pid GF_CLIENT_PID_TIER_DEFRAG
in dht_setxattr() just before calling dht_start_rebalance_task().

>    http://review.gluster.org/#/c/10266/
>    Change-Id: I86fef2d961b32fdd2c0c69d8512cbe846b393404
>    BUG: 1194753
>    Signed-off-by: Joseph Fernandes <josferna@redhat.com>
>    Reviewed-on: http://review.gluster.org/10266
>    Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
>    Reviewed-by: Susant Palai <spalai@redhat.com>
>    Reviewed-by: Dan Lambright <dlambrig@redhat.com>
>    Tested-by: Gluster Build System <jenkins@build.gluster.com>

Change-Id: I6ab42b2c7a3c3e21c461d097b7558ee967b62c62
BUG: 1218959
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Reviewed-on: http://review.gluster.org/10266
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
Reviewed-by: Susant Palai <spalai@redhat.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Reviewed-on: http://review.gluster.org/10601
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/xlators/cluster/dht/src/tier.c b/xlators/cluster/dht/src/tier.c
index 0663a7fb1cb..5be919800c2 100644
--- a/xlators/cluster/dht/src/tier.c
+++ b/xlators/cluster/dht/src/tier.c
@@ -219,6 +219,24 @@ tier_migrate_using_query_file (void *_args)
                         if (per_file_status) {
                                 goto per_file_out;
                         }
+
+                        /* Flag to suggest its a tiering migration
+                         * The reason for this dic key-value is that
+                         * promotions and demotions are multithreaded
+                         * so the original frame from gf_defrag_start()
+                         * is not carried. A new frame will be created when
+                         * we do syncop_setxattr(). This doesnot have the
+                         * frame->root->pid of the original frame. So we pass
+                         * this dic key-value when we do syncop_setxattr() to do
+                         * data migration and set the frame->root->pid to
+                         * GF_CLIENT_PID_TIER_DEFRAG in dht_setxattr() just before
+                         * calling dht_start_rebalance_task() */
+                        per_file_status = dict_set_str (migrate_data,
+                                                "tiering.migration", "yes");
+                        if (per_file_status) {
+                                goto per_file_out;
+                        }
+
                 }
                 per_link_status = 0;
                 /* Per link of file */