features/shard: Fix block-count accounting upon truncate to lower size

The way delta_blocks is computed in shard is incorrect, when a file
is truncated to a lower size. The accounting only considers change
in size of the last of the truncated shards.

FIX:

Get the block-count of each shard just before an unlink at posix in
xdata.  Their summation plus the change in size of last shard
(from an actual truncate) is used to compute delta_blocks which is
used in the xattrop for size update.

Change-Id: I9128a192e9bf8c3c3a959e96b7400879d03d7c53
fixes: bz#1705884
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/bugs/shard/bug-1705884.t b/tests/bugs/shard/bug-1705884.t
new file mode 100644
index 00000000000..f6e50376a58
--- /dev/null
+++ b/tests/bugs/shard/bug-1705884.t
@@ -0,0 +1,32 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+. $(dirname $0)/../../fallocate.rc
+
+cleanup
+
+require_fallocate -l 1m $M0/file
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 replica 3 $H0:$B0/${V0}{0,1,2}
+TEST $CLI volume set $V0 features.shard on
+TEST $CLI volume set $V0 performance.write-behind off
+TEST $CLI volume set $V0 performance.stat-prefetch off
+TEST $CLI volume start $V0
+
+TEST $GFS --volfile-id=$V0 --volfile-server=$H0 $M0
+
+TEST fallocate -l 200M $M0/foo
+EXPECT `echo "$(( ( 200 * 1024 * 1024 ) / 512 ))"`  stat -c %b $M0/foo
+TEST truncate -s 0 $M0/foo
+EXPECT "0" stat -c %b $M0/foo
+TEST fallocate -l 100M $M0/foo
+EXPECT `echo "$(( ( 100 * 1024 * 1024 ) / 512 ))"`  stat -c %b $M0/foo
+
+EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0
+TEST $CLI volume stop $V0
+TEST $CLI volume delete $V0
+
+cleanup