storage/posix: Add free space limits to bricks

Summary:
- Add a configurable minimum free space for bricks, using the new
  options storage.min-free-disk (analagous to cluster.min-free-disk,
  and using the same units: either a percentage or an
  absolute number of bytes) and storage.freespace-check-interval
  (how frequently to check free space, in seconds).
- This is a cherry-pick of D2920210 to 3.8

Signed-off-by: Shreyas Siravara <sshreyas@fb.com>

Change-Id: I4b87e421aad023e49b5972c6e61539670a818411
Reviewed-on: http://review.gluster.org/16176
Tested-by: Shreyas Siravara <sshreyas@fb.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Kevin Vigor <kvigor@fb.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

1 files changed, 113 insertions, 0 deletions

diff --git a/tests/features/brick-min-free-space.t b/tests/features/brick-min-free-space.t
new file mode 100755
index 00000000000..4372998681f
--- /dev/null
+++ b/tests/features/brick-min-free-space.t
@@ -0,0 +1,113 @@
+#!/bin/bash
+#
+# Test storage.min-free-disk option works.
+#
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+
+cleanup;
+
+TEST glusterd
+
+TEST truncate -s 16M $B0/brick0
+TEST LOOPDEV=$(losetup --find --show $B0/brick0)
+TEST mkfs.xfs $LOOPDEV
+
+mkdir -p $B0/$V0
+
+TEST mount -t xfs $LOOPDEV $B0/$V0
+
+###########
+# AIO on  #
+###########
+
+TEST $CLI volume create $V0 $H0:$B0/$V0
+TEST $CLI volume start $V0
+TEST $CLI volume set $V0 readdir-ahead on
+TEST $CLI vol set $V0 storage.linux-aio on
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 $M0
+
+# Filesystem has ~12MB capacity after XFS and glusterfs overhead.
+# A 16MB write should blow up.
+TEST ! dd if=/dev/zero of=$M0/test bs=1M count=16 oflag=direct
+TEST rm $M0/test
+
+# But we should be able to write 10MB
+TEST dd if=/dev/zero of=$M0/test bs=1M count=10 oflag=direct
+
+# Now enable limit and set to at least 8MB free space
+TEST $CLI volume set $V0 storage.freespace-check-interval 1
+TEST $CLI volume set $V0 storage.min-free-disk 8388608
+
+# Now even a tiny write ought fail.
+TEST ! dd if=/dev/zero of=$M0/test1 bs=1M count=1 oflag=direct
+TEST rm $M0/test1
+
+# Repeat using percent syntax.
+TEST $CLI volume set $V0 storage.min-free-disk 33%
+
+TEST ! dd if=/dev/zero of=$M0/test1 bs=4K count=1 oflag=direct
+TEST rm $M0/test1
+
+# Disable limit.
+TEST $CLI volume set $V0 storage.freespace-check-interval 0
+
+# Now we can write again.
+TEST dd if=/dev/zero of=$M0/test1 bs=4K count=1 oflag=direct
+
+TEST rm $M0/test1
+TEST rm $M0/test
+
+EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0;
+TEST $CLI volume stop $V0
+TEST $CLI volume delete $V0
+
+############
+# AIO off  #
+############
+
+TEST $CLI volume create $V0 $H0:$B0/$V0
+TEST $CLI volume start $V0
+TEST $CLI volume set $V0 readdir-ahead on
+TEST $CLI vol set $V0 storage.linux-aio off
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 $M0
+
+# Filesystem has ~12MB capacity after XFS and glusterfs overhead.
+# A 16MB write should blow up.
+TEST ! dd if=/dev/zero of=$M0/test bs=1M count=16 oflag=direct
+TEST rm $M0/test
+
+# But we should be able to write 10MB
+TEST dd if=/dev/zero of=$M0/test bs=1M count=10 oflag=direct
+
+# Now enable limit and set to at least 8MB free space
+TEST $CLI volume set $V0 storage.freespace-check-interval 1
+TEST $CLI volume set $V0 storage.min-free-disk 8388608
+
+# Now even a tiny write ought fail.
+TEST ! dd if=/dev/zero of=$M0/test1 bs=1M count=1 oflag=direct
+TEST rm $M0/test1
+
+# Repeat using percent syntax.
+TEST $CLI volume set $V0 storage.min-free-disk 33%
+
+TEST ! dd if=/dev/zero of=$M0/test1 bs=4K count=1 oflag=direct
+TEST rm $M0/test1
+
+# Disable limit.
+TEST $CLI volume set $V0 storage.freespace-check-interval 0
+
+# Now we can write again.
+TEST dd if=/dev/zero of=$M0/test1 bs=4K count=1 oflag=direct
+
+TEST rm $M0/test1
+TEST rm $M0/test
+
+EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0;
+TEST $CLI volume stop $V0
+TEST $CLI volume delete $V0
+
+cleanup;