From 2ca340c34e820ef4232ee20f1084fe4803ca2140 Mon Sep 17 00:00:00 2001

From: moagrawa <moagrawa@redhat.com>

Date: Tue, 29 Nov 2016 11:12:00 +0530

Subject: [PATCH 206/206] cluster/dht: A hard link is lost during rebalance +

 lookup

Problem: A hard link is lost during rebalance + lookup.Rebalance skip

         files if file has hardlink.In dht_migrate_file

         __is_file_migratable () function checks if a file has hardlink,

         if yes file is not migrated but if link is created after call

         this function then link will lost.

Solution: Call __check_file_has_hardlink to check hardlink existence

          after (S+T) bits in migration process ,if file has hardlink

          then skip the file for migrate rebalance process.

> BUG: 1396048

> Change-Id: Ia53c07ef42f1128c2eedf959a757e8df517b9d12

> Signed-off-by: Mohit Agrawal <moagrawa@redhat.com>

> Reviewed-on: http://review.gluster.org/15866

> Reviewed-by: Susant Palai <spalai@redhat.com>

> Smoke: Gluster Build System <jenkins@build.gluster.org>

> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>

> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

> Reviewed-by: N Balachandran <nbalacha@redhat.com>

> Reviewed-by: Raghavendra G <rgowdapp@redhat.com>

> (cherry picked from commit 71dd2e914d4a537bf74e1ec3a24512fc83bacb1d)

BUG: 1392837

Change-Id: I7d96c56e497c0cefe40093c4588c53ef8540fc3d

Signed-off-by: moagrawa <moagrawa@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/91494

Reviewed-by: Raghavendra Gowdappa <rgowdapp@redhat.com>

---

 xlators/cluster/dht/src/dht-rebalance.c | 101 ++++++++++++++++++++------------

 1 file changed, 62 insertions(+), 39 deletions(-)

diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c

index 2373e9d..c82700e 100644

--- a/xlators/cluster/dht/src/dht-rebalance.c

+++ b/xlators/cluster/dht/src/dht-rebalance.c

@@ -464,6 +464,50 @@ out:

         return ret;

 }

+

+static int

+__check_file_has_hardlink (xlator_t *this, loc_t *loc,

+                      struct iatt *stbuf, dict_t *xattrs, int flags,

+                                gf_defrag_info_t *defrag)

+{

+       int ret = 0;

+

+       if (flags == GF_DHT_MIGRATE_HARDLINK_IN_PROGRESS) {

+                ret = 0;

+                return ret;

+       }

+       if (stbuf->ia_nlink > 1) {

+                /* support for decomission */

+                if (flags == GF_DHT_MIGRATE_HARDLINK) {

+                        synclock_lock (&defrag->link_lock);

+                        ret = gf_defrag_handle_hardlink

+                                (this, loc, xattrs, stbuf);

+                        synclock_unlock (&defrag->link_lock);

+                        /*

+                          Returning zero will force the file to be remigrated.

+                          Checkout gf_defrag_handle_hardlink for more

+                          information.

+                        */

+                        if (ret && ret != -2) {

+                                gf_msg (this->name, GF_LOG_WARNING, 0,

+                                        DHT_MSG_MIGRATE_FILE_FAILED,

+                                        "Migrate file failed:"

+                                        "%s: failed to migrate file with link",

+                                        loc->path);

+                        }

+                } else {

+                        gf_msg (this->name, GF_LOG_WARNING, 0,

+                                DHT_MSG_MIGRATE_FILE_FAILED,

+                                "Migrate file failed:"

+                                "%s: file has hardlinks", loc->path);

+                        ret = -ENOTSUP;

+                }

+       }

+

+       return ret;

+}

+

+

 /*

      return values

      0 : File will be migrated

@@ -512,41 +556,9 @@ __is_file_migratable (xlator_t *this, loc_t *loc,

                 }

         }

-        if (flags == GF_DHT_MIGRATE_HARDLINK_IN_PROGRESS) {

-                ret = 0;

-                goto out;

-        }

-

-        if (stbuf->ia_nlink > 1) {

-                /* support for decomission */

-                if (flags == GF_DHT_MIGRATE_HARDLINK) {

-                        synclock_lock (&defrag->link_lock);

-                        ret = gf_defrag_handle_hardlink

-                                (this, loc, xattrs, stbuf);

-                        synclock_unlock (&defrag->link_lock);

-                        /*

-                        Returning zero will force the file to be remigrated.

-                        Checkout gf_defrag_handle_hardlink for more information.

-                        */

-                        if (ret && ret != -2) {

-                                gf_msg (this->name, GF_LOG_WARNING, 0,

-                                        DHT_MSG_MIGRATE_FILE_FAILED,

-                                        "Migrate file failed:"

-                                        "%s: failed to migrate file with link",

-                                        loc->path);

-                        }

-                } else {

-                        gf_msg (this->name, GF_LOG_WARNING, 0,

-                                DHT_MSG_MIGRATE_FILE_FAILED,

-                                "Migrate file failed:"

-                                "%s: file has hardlinks", loc->path);

-                        ret = -ENOTSUP;

-                }

-                goto out;

-        }

-

-        ret = 0;

-

+        /* Check if file has hardlink*/

+        ret = __check_file_has_hardlink (this, loc, stbuf, xattrs,

+                                         flags, defrag);

 out:

         return ret;

 }

@@ -1368,9 +1380,6 @@ dht_migrate_file (xlator_t *this, loc_t *loc, xlator_t *from, xlator_t *to,

                 goto out;

         }

-        /* we no more require this key */

-        dict_del (dict, conf->link_xattr_name);

-

         /* preserve source mode, so set the same to the destination */

         src_ia_prot = stbuf.ia_prot;

@@ -1425,8 +1434,13 @@ dht_migrate_file (xlator_t *this, loc_t *loc, xlator_t *from, xlator_t *to,

                 goto out;

         }

+        if (xattr_rsp) {

+                /* we no more require this key */

+                dict_del (dict, conf->link_xattr_name);

+                dict_unref (xattr_rsp);

+        }

-        ret = syncop_fstat (from, src_fd, &stbuf, NULL, NULL);

+        ret = syncop_fstat (from, src_fd, &stbuf, dict, &xattr_rsp);

         if (ret) {

                 gf_msg (this->name, GF_LOG_ERROR, -ret,

                         DHT_MSG_MIGRATE_FILE_FAILED,

@@ -1436,6 +1450,15 @@ dht_migrate_file (xlator_t *this, loc_t *loc, xlator_t *from, xlator_t *to,

                 goto out;

         }

+        /* Check again if file has hardlink */

+        ret = __check_file_has_hardlink (this, loc, &stbuf, xattr_rsp,

+                                         flag, defrag);

+        if (ret) {

+                if (ret == -2)

+                        ret = 0;

+                goto out;

+        }

+

         /* Try to preserve 'holes' while migrating data */

         if (stbuf.ia_size > (stbuf.ia_blocks * GF_DISK_SECTOR_SIZE))

                 file_has_holes = 1;

-- 

2.9.3