From a47d863ea4501d3d0daceacb194c9f900cefe1a7 Mon Sep 17 00:00:00 2001
From: Kotresh HR <khiremat@redhat.com>
Date: Mon, 13 Nov 2017 05:27:50 -0500
Subject: [PATCH 119/128] geo-rep: Fix data sync issue during hardlink, rename
Problem:
The data is not getting synced if master witnessed
IO as below.
1. echo "test_data" > f1
2. ln f1 f2
3. mv f2 f3
4. unlink f1
On master, 'f3' exists with data "test_data" but on
slave, only f3 exists with zero byte file without
backend gfid link.
Cause:
On master, since 'f2' no longer exists, the hardlink
is skipped during processing. Later, on trying to sync
rename, since source ('f2') doesn't exist, dst ('f3')
is created with same gfid. But in this use case, it
succeeds but backend gfid would not have linked as 'f1'
exists with the same gfid. So, rsync would fail with
ENOENT as backend gfid is not linked with 'f3' and 'f1'
is unlinked.
Fix:
On processing rename, if src doesn't exist on slave,
don't blindly create dst with same gfid. The gfid
needs to be checked, if it exists, hardlink needs
to be created instead of mknod.
Thanks Aravinda for helping in RCA :)
Upstream Reference:
> Patch: https://review.gluster.org/18731
> BUG: 1512483
Change-Id: I5af4f99798ed1bcb297598a4bc796b701d1e0130
BUG: 1512496
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/126728
Tested-by: RHGS Build Bot <nigelb@redhat.com>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
---
geo-replication/syncdaemon/resource.py | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/geo-replication/syncdaemon/resource.py b/geo-replication/syncdaemon/resource.py
index 22aaf85..5ad5b97 100644
--- a/geo-replication/syncdaemon/resource.py
+++ b/geo-replication/syncdaemon/resource.py
@@ -814,8 +814,17 @@ class Server(object):
elif not matching_disk_gfid(gfid, en):
collect_failure(e, EEXIST, True)
else:
- (pg, bname) = entry2pb(en)
- blob = entry_pack_reg_stat(gfid, bname, e['stat'])
+ slink = os.path.join(pfx, gfid)
+ st = lstat(slink)
+ # don't create multiple entries with same gfid
+ if isinstance(st, int):
+ (pg, bname) = entry2pb(en)
+ blob = entry_pack_reg_stat(gfid, bname,
+ e['stat'])
+ else:
+ cmd_ret = errno_wrap(os.link, [slink, en],
+ [ENOENT, EEXIST], [ESTALE])
+ collect_failure(e, cmd_ret)
else:
st1 = lstat(en)
if isinstance(st1, int):
--
1.8.3.1