From 161a039f8088bf8ce7000d8175e3793219525179 Mon Sep 17 00:00:00 2001

From: Kotresh HR <khiremat@redhat.com>

Date: Thu, 28 Mar 2019 07:17:16 -0400

Subject: [PATCH 50/52] geo-rep: Fix syncing multiple rename of symlink

Problem:

Geo-rep fails to sync rename of symlink if it's

renamed multiple times if creation and rename

happened successively

Worker crash at slave:

Traceback (most recent call last):

  File "/usr/libexec/glusterfs/python/syncdaemon/repce.py",  in worker

    res = getattr(self.obj, rmeth)(*in_data[2:])

  File "/usr/libexec/glusterfs/python/syncdaemon/resource.py", in entry_ops

    [ESTALE, EINVAL, EBUSY])

  File "/usr/libexec/glusterfs/python/syncdaemon/syncdutils.py", in errno_wrap

    return call(*arg)

  File "/usr/libexec/glusterfs/python/syncdaemon/libcxattr.py", in lsetxattr

    cls.raise_oserr()

  File "/usr/libexec/glusterfs/python/syncdaemon/libcxattr.py", in raise_oserr

    raise OSError(errn, os.strerror(errn))

OSError: [Errno 12] Cannot allocate memory

Geo-rep Behaviour:

1. SYMLINK doesn't record target path in changelog.

   So while syncing SYMLINK, readlink is done on

   master to get target path.

2. Geo-rep will create destination if source is not

   present while syncing RENAME. Hence while syncing

   RENAME of SYMLINK, target path is collected from

   destination.

Cause:

If symlink is created and renamed multiple times, creation of

symlink is ignored, as it's no longer present on master at

that path. While symlink is renamed multiple times at master,

when syncing first RENAME of SYMLINK, both source and destination

is not present, hence target path is not known.  In this case,

while creating destination directly at slave,  regular file

attributes were encoded into blob instead of symlink,

causing failure in gfid-access translator while decoding

blob.

Solution:

While syncing of RENAME of SYMLINK, when target is not known

and when src and destination is not present on the master,

don't create destination. Ignore the rename. It's ok to ignore.

If it's unliked, it's fine.  If it's renamed to something else,

it will be synced then.

Backport of:

> Patch: https://review.gluster.org/22438

> Change-Id: Ibdfa495513b7c05b5370ab0b89c69a6802338d87

> BUG: 1693648

> Signed-off-by: Kotresh HR <khiremat@redhat.com>

Change-Id: Ibdfa495513b7c05b5370ab0b89c69a6802338d87

fixes: bz#1670429

Signed-off-by: Kotresh HR <khiremat@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/167122

Tested-by: RHGS Build Bot <nigelb@redhat.com>

Reviewed-by: Sunil Kumar Heggodu Gopala Acharya <sheggodu@redhat.com>

---

 geo-replication/syncdaemon/resource.py   | 23 ++++++++++++++---------

 tests/00-geo-rep/georep-basic-dr-rsync.t |  1 +

 tests/geo-rep.rc                         | 12 ++++++++++++

 3 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/geo-replication/syncdaemon/resource.py b/geo-replication/syncdaemon/resource.py

index a2d0b16..c290d86 100644

--- a/geo-replication/syncdaemon/resource.py

+++ b/geo-replication/syncdaemon/resource.py

@@ -625,15 +625,20 @@ class Server(object):

                 # exist with different gfid.

                 if not matching_disk_gfid(gfid, entry):

                     if e['stat'] and not stat.S_ISDIR(e['stat']['mode']):

-                        if stat.S_ISLNK(e['stat']['mode']) and \

-                           e['link'] is not None:

-                            st1 = lstat(en)

-                            if isinstance(st1, int):

-                                (pg, bname) = entry2pb(en)

-                                blob = entry_pack_symlink(cls, gfid, bname,

-                                                          e['link'], e['stat'])

-                            elif not matching_disk_gfid(gfid, en):

-                                collect_failure(e, EEXIST, uid, gid, True)

+                        if stat.S_ISLNK(e['stat']['mode']):

+                            # src is not present, so don't sync symlink as

+                            # we don't know target. It's ok to ignore. If

+                            # it's unliked, it's fine. If it's renamed to

+                            # something else, it will be synced then.

+                            if e['link'] is not None:

+                                st1 = lstat(en)

+                                if isinstance(st1, int):

+                                    (pg, bname) = entry2pb(en)

+                                    blob = entry_pack_symlink(cls, gfid, bname,

+                                                              e['link'],

+                                                              e['stat'])

+                                elif not matching_disk_gfid(gfid, en):

+                                    collect_failure(e, EEXIST, uid, gid, True)

                         else:

                             slink = os.path.join(pfx, gfid)

                             st = lstat(slink)

diff --git a/tests/00-geo-rep/georep-basic-dr-rsync.t b/tests/00-geo-rep/georep-basic-dr-rsync.t

index 4a03930..8b64370 100644

--- a/tests/00-geo-rep/georep-basic-dr-rsync.t

+++ b/tests/00-geo-rep/georep-basic-dr-rsync.t

@@ -110,6 +110,7 @@ EXPECT_WITHIN $GEO_REP_TIMEOUT 0 chown_file_ok ${slave_mnt}/hybrid_chown_f1

 #Check History Crawl.

 TEST $GEOREP_CLI $master $slave stop

 TEST create_data "history"

+TEST create_rename_symlink_case

 TEST $GEOREP_CLI $master $slave start

 EXPECT_WITHIN $GEO_REP_TIMEOUT  2 check_status_num_rows "Active"

 EXPECT_WITHIN $GEO_REP_TIMEOUT  2 check_status_num_rows "Passive"

diff --git a/tests/geo-rep.rc b/tests/geo-rep.rc

index 396b4c4..d723129 100644

--- a/tests/geo-rep.rc

+++ b/tests/geo-rep.rc

@@ -19,6 +19,18 @@ function check_common_secret_file()

     echo $?

 }

+function create_rename_symlink_case()

+{

+    mkdir ${mastermnt}/MUL_REN_SYMLINK

+    cd ${mastermnt}/MUL_REN_SYMLINK

+    mkdir sym_dir1

+    ln -s "sym_dir1" sym1

+    mv sym1 sym2

+    mv sym2 sym3

+    mv sym3 sym4

+    cd -

+}

+

 function create_data()

 {

     prefix=$1

-- 

1.8.3.1