From 87a24e342c422ba6b04563d63d431430c0156b52 Mon Sep 17 00:00:00 2001 From: N Balachandran Date: Fri, 6 Apr 2018 16:06:51 +0530 Subject: [PATCH 217/236] cluster/dht: Handle file migrations when brick down The decision as to which node would migrate a file was based on the gfid of the file. Files were divided among the nodes for the replica/disperse set. However, if a brick was down when rebalance started, the nodeuuids would be saved as NULL and a set of files would not be migrated. Now, if the nodeuuid is NULL, the first non-null entry in the set is the node responsible for migrating the file. upstream master: https://review.gluster.org/#/c/19831/ > Change-Id: I72554c107792c7d534e0f25640654b6f8417d373 > fixes: bz#1564198 > Signed-off-by: N Balachandran Change-Id: Ia0e15339aefee2712e85d7e282c9b7934665376b BUG: 1553677 Signed-off-by: N Balachandran Reviewed-on: https://code.engineering.redhat.com/gerrit/135515 Tested-by: RHGS Build Bot Reviewed-by: Atin Mukherjee --- xlators/cluster/dht/src/dht-rebalance.c | 56 ++++++++++++++++++++++++++++++--- 1 file changed, 51 insertions(+), 5 deletions(-) diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c index bba44b9..a4be348 100644 --- a/xlators/cluster/dht/src/dht-rebalance.c +++ b/xlators/cluster/dht/src/dht-rebalance.c @@ -2469,6 +2469,27 @@ gf_defrag_ctx_subvols_init (dht_dfoffset_ctx_t *offset_var, xlator_t *this) { } +static int +dht_get_first_non_null_index (subvol_nodeuuids_info_t *entry) +{ + int i = 0; + int index = 0; + + for (i = 0; i < entry->count; i++) { + if (!gf_uuid_is_null (entry->elements[i].uuid)) { + index = i; + goto out; + } + } + + if (i == entry->count) { + index = -1; + } +out: + return index; +} + + /* Return value * 0 : this node does not migrate the file * 1 : this node migrates the file @@ -2485,28 +2506,53 @@ gf_defrag_should_i_migrate (xlator_t *this, int local_subvol_index, uuid_t gfid) int i = local_subvol_index; char *str = NULL; uint32_t hashval = 0; - int32_t index = 0; + int32_t index = 0; dht_conf_t *conf = NULL; char buf[UUID_CANONICAL_FORM_LEN + 1] = {0, }; + subvol_nodeuuids_info_t *entry = NULL; + conf = this->private; - /* Pure distribute */ + /* Pure distribute. A subvol in this case + will be handled by only one node */ - if (conf->local_nodeuuids[i].count == 1) { + entry = &(conf->local_nodeuuids[i]); + if (entry->count == 1) { return 1; } str = uuid_utoa_r (gfid, buf); ret = dht_hash_compute (this, 0, str, &hashval); if (ret == 0) { - index = (hashval % conf->local_nodeuuids[i].count); - if (conf->local_nodeuuids[i].elements[index].info + index = (hashval % entry->count); + if (entry->elements[index].info == REBAL_NODEUUID_MINE) { /* Index matches this node's nodeuuid.*/ ret = 1; + goto out; + } + + /* Brick down - some other node has to migrate these files*/ + if (gf_uuid_is_null (entry->elements[index].uuid)) { + /* Fall back to the first non-null index */ + index = dht_get_first_non_null_index (entry); + + if (index == -1) { + /* None of the bricks in the subvol are up. + * CHILD_DOWN will kill the process soon */ + + return 0; + } + + if (entry->elements[index].info == REBAL_NODEUUID_MINE) { + /* Index matches this node's nodeuuid.*/ + ret = 1; + goto out; + } } } +out: return ret; } -- 1.8.3.1