diff options
Diffstat (limited to 'xlators/cluster/afr/src/afr-common.c')
| -rw-r--r-- | xlators/cluster/afr/src/afr-common.c | 67 |
1 files changed, 59 insertions, 8 deletions
diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c index 300ab92efaf..21a2be3dd6f 100644 --- a/xlators/cluster/afr/src/afr-common.c +++ b/xlators/cluster/afr/src/afr-common.c @@ -546,6 +546,10 @@ afr_is_read_child (int32_t *success_children, int32_t *sources, gf_boolean_t success_child = _gf_false; gf_boolean_t source = _gf_false; + if (child < 0) { + return _gf_false; + } + GF_ASSERT (success_children); GF_ASSERT (child_count > 0); @@ -562,13 +566,44 @@ out: return (success_child && source); } +int32_t +afr_hash_child (int32_t *success_children, int32_t child_count, + unsigned int hmode, uuid_t gfid) +{ + uuid_t gfid_copy = {0,}; + + if (!hmode) { + return -1; + } + + if (gfid) { + uuid_copy(gfid_copy,gfid); + } + if (hmode > 1) { + /* + * Why getpid? Because it's one of the cheapest calls + * available - faster than gethostname etc. - and returns a + * constant-length value that's sure to be shorter than a UUID. + * It's still very unlikely to be the same across clients, so + * it still provides good mixing. We're not trying for + * perfection here. All we need is a low probability that + * multiple clients won't converge on the same subvolume. + */ + *((pid_t *)gfid_copy) = getpid(); + } + + return SuperFastHash((char *)gfid_copy, + sizeof(gfid_copy)) % child_count; +} + /* If sources is NULL the xattrs are assumed to be of source for all * success_children. */ int -afr_select_read_child_from_policy (int32_t *success_children, int32_t child_count, - int32_t prev_read_child, - int32_t config_read_child, int32_t *sources) +afr_select_read_child_from_policy (int32_t *success_children, + int32_t child_count, int32_t prev_read_child, + int32_t config_read_child, int32_t *sources, + unsigned int hmode, uuid_t gfid) { int32_t read_child = -1; int i = 0; @@ -585,6 +620,13 @@ afr_select_read_child_from_policy (int32_t *success_children, int32_t child_coun read_child)) goto out; + read_child = afr_hash_child (success_children, child_count, + hmode, gfid); + if (afr_is_read_child (success_children, sources, child_count, + read_child)) { + goto out; + } + for (i = 0; i < child_count; i++) { read_child = success_children[i]; if (read_child < 0) @@ -604,7 +646,7 @@ out: void afr_set_read_ctx_from_policy (xlator_t *this, inode_t *inode, int32_t *fresh_children, int32_t prev_read_child, - int32_t config_read_child) + int32_t config_read_child, uuid_t gfid) { int read_child = -1; afr_private_t *priv = NULL; @@ -614,7 +656,8 @@ afr_set_read_ctx_from_policy (xlator_t *this, inode_t *inode, priv->child_count, prev_read_child, config_read_child, - NULL); + NULL, + priv->hash_mode, gfid); if (read_child >= 0) afr_inode_set_read_ctx (this, inode, read_child, fresh_children); @@ -1271,6 +1314,7 @@ afr_lookup_select_read_child (afr_local_t *local, xlator_t *this, dict_t **xattrs = NULL; int32_t *success_children = NULL; afr_transaction_type type = AFR_METADATA_TRANSACTION; + uuid_t *gfid = NULL; GF_ASSERT (local); GF_ASSERT (this); @@ -1284,8 +1328,9 @@ afr_lookup_select_read_child (afr_local_t *local, xlator_t *this, ia_type = local->cont.lookup.bufs[success_children[0]].ia_type; type = afr_transaction_type_get (ia_type); xattrs = local->cont.lookup.xattrs; + gfid = &local->cont.lookup.buf.ia_gfid; source = afr_lookup_select_read_child_by_txn_type (this, local, xattrs, - type); + type, *gfid); if (source < 0) { gf_log (this->name, GF_LOG_DEBUG, "failed to select source " "for %s", local->loc.path); @@ -2131,8 +2176,14 @@ afr_lookup (call_frame_t *frame, xlator_t *this, } else { LOCK (&priv->read_child_lock); { - local->read_child_index = (++priv->read_child_rr) - % (priv->child_count); + if (priv->hash_mode) { + local->read_child_index = -1; + } + else { + local->read_child_index = + (++priv->read_child_rr) % + (priv->child_count); + } } UNLOCK (&priv->read_child_lock); local->cont.lookup.fresh_lookup = _gf_true; |