posix: option to handle the shared bricks for statvfs()

Currently 'storage/posix' xlator has an option called option
`export-statfs-size no`, which exports zero as values for few
fields in `struct statvfs`. In a case of backend brick shared
between multiple brick processes, the values of these variables
should be `field_value / number-of-bricks-at-node`. This way,
even the issue of 'min-free-disk' etc at different layers would
also be handled properly when the statfs() sys call is made.

Fixes #241

> Reviewed-on: https://review.gluster.org/17618
> Reviewed-by: Jeff Darcy <jeff@pl.atyp.us>
> Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
> (cherry picked from commit febf5ed4848ad705a34413353559482417c61467)

Change-Id: I2e320e1fdcc819ab9173277ef3498201432c275f
Signed-off-by: Amar Tumballi <amarts@redhat.com>
Reviewed-on: https://review.gluster.org/17903
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/tests/basic/posix/shared-statfs.t b/tests/basic/posix/shared-statfs.t
new file mode 100644
index 00000000000..8caa9fa2110
--- /dev/null
+++ b/tests/basic/posix/shared-statfs.t
@@ -0,0 +1,53 @@
+#!/bin/bash
+#Test that statfs is not served from posix backend FS.
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+
+cleanup;
+TEST glusterd
+
+#Create brick partitions
+TEST truncate -s 100M $B0/brick1
+TEST truncate -s 100M $B0/brick2
+LO1=`SETUP_LOOP $B0/brick1`
+TEST [ $? -eq 0 ]
+TEST MKFS_LOOP $LO1
+LO2=`SETUP_LOOP $B0/brick2`
+TEST [ $? -eq 0 ]
+TEST MKFS_LOOP $LO2
+TEST mkdir -p $B0/${V0}1 $B0/${V0}2
+TEST MOUNT_LOOP $LO1 $B0/${V0}1
+TEST MOUNT_LOOP $LO2 $B0/${V0}2
+
+# Create a subdir in mountpoint and use that for volume.
+TEST $CLI volume create $V0 $H0:$B0/${V0}1/1 $H0:$B0/${V0}2/1;
+TEST $CLI volume start $V0
+TEST $GFS --volfile-server=$H0 --volfile-id=$V0 $M0
+total_space=$(df -P $M0 | tail -1 | awk '{ print $2}')
+# Keeping the size less than 200M mainly because XFS will use
+# some storage in brick to keep its own metadata.
+TEST [ $total_space -gt 194000 -a $total_space -lt 200000 ]
+
+
+TEST force_umount $M0
+TEST $CLI volume stop $V0
+EXPECT 'Stopped' volinfo_field $V0 'Status';
+
+# From the same mount point, share another 2 bricks with the volume
+TEST $CLI volume add-brick $V0 $H0:$B0/${V0}1/2 $H0:$B0/${V0}2/2 $H0:$B0/${V0}1/3 $H0:$B0/${V0}2/3
+
+TEST $CLI volume start $V0
+TEST $GFS --volfile-server=$H0 --volfile-id=$V0 $M0
+total_space=$(df -P $M0 | tail -1 | awk '{ print $2}')
+TEST [ $total_space -gt 194000 -a $total_space -lt 200000 ]
+
+TEST force_umount $M0
+TEST $CLI volume stop $V0
+EXPECT 'Stopped' volinfo_field $V0 'Status';
+
+TEST $CLI volume delete $V0;
+
+UMOUNT_LOOP ${B0}/${V0}{1,2}
+rm -f ${B0}/brick{1,2}
+cleanup;