ctime: Fix self heal of symlink in EC volume

Since IEEE Std 1003.1-2001 does not require any
association of file times with symbolic links,
there is no requirement that file times be
updated by readlink() states [1].

stat on symlink file was generating a readlink
fop on one of the subvolumes of ec set which
in turn updates atime on that subvolume. This
causes mdata xattr to be different across ec
set and hence self heal fails. So based on [1],
atime is no longer updated by readlink fop.

[1] http://pubs.opengroup.org/onlinepubs/009695399/functions/readlink.html

Backport of:
  > Patch: https://review.gluster.org/#/c/20311/
  > BUG: 1592509
  > Change-Id: I08bd3ca3bdb222bd18160b1aa58fc2f7630c8083
  > Signed-off-by: Kotresh HR <khiremat@redhat.com>
  (cherry picked from commit c097a7894d458e33a41f6db6092677108ef30fec)

fixes: bz#1593536
Change-Id: I08bd3ca3bdb222bd18160b1aa58fc2f7630c8083
Signed-off-by: Kotresh HR <khiremat@redhat.com>
(cherry picked from commit c097a7894d458e33a41f6db6092677108ef30fec)

1 files changed, 69 insertions, 0 deletions

diff --git a/tests/basic/ctime/ctime-heal-symlinks.t b/tests/basic/ctime/ctime-heal-symlinks.t
new file mode 100644
index 00000000000..3922b12546d
--- /dev/null
+++ b/tests/basic/ctime/ctime-heal-symlinks.t
@@ -0,0 +1,69 @@
+#!/bin/bash
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+. $(dirname $0)/../../afr.rc
+cleanup;
+
+###############################################################################
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 replica 3 $H0:$B0/${V0}{0,1,2}
+TEST $CLI volume set $V0 performance.stat-prefetch off
+TEST $CLI volume set $V0 ctime on
+TEST $CLI volume set $V0 utime on
+TEST $CLI volume start $V0
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 --entry-timeout=0 $M0;
+
+cd $M0
+TEST "echo hello_world > FILE"
+TEST ln -s FILE SOFTLINK
+
+# Remove symlink only (not the .glusterfs entry) and trigger named heal.
+TEST rm -f $B0/${V0}2/SOFTLINK
+TEST stat SOFTLINK
+
+# To heal and clear new-entry mark on source bricks.
+TEST $CLI volume heal $V0
+EXPECT_WITHIN $HEAL_TIMEOUT "^0$" get_pending_heal_count $V0
+
+EXPECT 2 stat -c %h  $B0/${V0}2/SOFTLINK
+EXPECT "hello_world" cat $B0/${V0}2/SOFTLINK
+
+cd -
+cleanup
+###############################################################################
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 disperse 3 redundancy 1  $H0:$B0/${V0}{0,1,2}
+TEST $CLI volume set $V0 performance.stat-prefetch off
+TEST $CLI volume set $V0 ctime on
+TEST $CLI volume set $V0 utime on
+TEST $CLI volume start $V0
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 --entry-timeout=0 $M0;
+
+cd $M0
+TEST "echo hello_world > FILE"
+TEST ln -s FILE SOFTLINK
+
+# Remove symlink only (not the .glusterfs entry) and trigger named heal.
+TEST rm -f $B0/${V0}2/SOFTLINK
+TEST stat SOFTLINK
+
+# To heal and clear new-entry mark on source bricks.
+TEST $CLI volume heal $V0
+EXPECT_WITHIN $HEAL_TIMEOUT "^0$" get_pending_heal_count $V0
+
+EXPECT 2 stat -c %h  $B0/${V0}2/SOFTLINK
+TEST kill_brick $V0 $H0 $B0/${V0}0
+cd -
+EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 --entry-timeout=0 $M0;
+cd $M0
+EXPECT "hello_world" cat SOFTLINK
+
+cd -
+cleanup
+###############################################################################