cluster/dht: Fix min-free-disk calculations when quota-deem-statfs is on

PROBLEM:

As part of file creation, DHT sends a statfs call to all of its
sub-volumes and expects in return the local space consumption and
availability on each one of them. This information is used by DHT to
ensure that atleast min-free-disk amount of space is left on each
sub-volume in the event that there ARE other sub-volumes with more
space available.
But when quota-deem-statfs is enabled, quota xlator on every brick
unwinds the statfs call with volume-wide consumption of disk space.
This leads to miscalculation in min-free-disk algo, thereby misleading
DHT at some point, into thinking all sub-volumes have equal available
space, in which case DHT keeps sending new file creates to subvol-0,
causing it to become 100% full at some point although there ARE other
subvols with ample space available.

FIX:

The fix is to make quota_statfs() behave as if quota xlator weren't
enabled, thereby making every brick return only its local consumption
and disk space availability.

Change-Id: I211371a1eddb220037bd36a128973938ea8124c2
BUG: 1099890
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/7845
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 15 insertions, 1 deletions

diff --git a/xlators/cluster/dht/src/dht-diskusage.c b/xlators/cluster/dht/src/dht-diskusage.c
index fe3955ecbb7..d035aca2665 100644
--- a/xlators/cluster/dht/src/dht-diskusage.c
+++ b/xlators/cluster/dht/src/dht-diskusage.c
@@ -135,6 +135,7 @@ int
 dht_get_du_info (call_frame_t *frame, xlator_t *this, loc_t *loc)
 {
 	int            i            = 0;
+        int            ret          = -1;
 	dht_conf_t    *conf         = NULL;
 	call_frame_t  *statfs_frame = NULL;
 	dht_local_t   *statfs_local = NULL;
@@ -164,12 +165,25 @@ dht_get_du_info (call_frame_t *frame, xlator_t *this, loc_t *loc)
 			goto err;
 		}
 
+                statfs_local->params = dict_new ();
+                if (!statfs_local->params)
+                        goto err;
+
+                ret = dict_set_int8 (statfs_local->params,
+                                     GF_INTERNAL_IGNORE_DEEM_STATFS, 1);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Failed to set "
+                                GF_INTERNAL_IGNORE_DEEM_STATFS" in dict");
+                        goto err;
+                }
+
 		statfs_local->call_cnt = conf->subvolume_cnt;
 		for (i = 0; i < conf->subvolume_cnt; i++) {
 			STACK_WIND (statfs_frame, dht_du_info_cbk,
 				    conf->subvolumes[i],
 				    conf->subvolumes[i]->fops->statfs,
-				    &tmp_loc, NULL);
+				    &tmp_loc, statfs_local->params);
 		}
 
 		conf->last_stat_fetch.tv_sec = tv.tv_sec;