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, 19 insertions, 0 deletions

diff --git a/tests/dht.rc b/tests/dht.rc
index a11bbfd8a97..50c4532617e 100644
--- a/tests/dht.rc
+++ b/tests/dht.rc
@@ -91,3 +91,22 @@ function remove_brick_completed()
        echo $val
        return $val
 }
+
+function dht_get_linkto_target()
+{
+        local path=$1;
+        echo `getfattr -d -m . -e text --only-values --absolute-names --name=trusted.glusterfs.dht.linkto $path`
+}
+
+function is_dht_linkfile()
+{
+        local path=$1
+        retval=0
+        local output=`stat --format=%a $path`
+        if [ $output -eq 1000 ]; then
+                 retval=1
+        fi
+
+        echo $retval
+        return $retval
+}