cluster/afr: Fix dict-leak in pre-op

At the time of pre-op, pre_op_xdata is populted with the xattrs we get from the
disk and at the time of post-op it gets over-written without unreffing the
previous value stored leading to a leak.
This is a regression we missed in
https://review.gluster.org/#/q/ba149bac92d169ae2256dbc75202dc9e5d06538e


Originally:
> Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
> (cherry picked from commit e7b79c59590c203c65f7ac8548b30d068c232d33)

Change-Id: I0456f9ad6f77ce6248b747964a037193af3a3da7
Fixes: bz#1613512
Signed-off-by: Amar Tumballi <amarts@redhat.com>

3 files changed, 20 insertions, 20 deletions

diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index 0ffd59d65e2..613f9d1db75 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -1039,7 +1039,7 @@ afr_readables_fill (call_frame_t *frame, xlator_t *this, inode_t *inode,
                         xdata = replies[i].xdata;
                         ia_type = replies[i].poststat.ia_type;
                 } else {/* pre-op xattrop */
-                        xdata = local->transaction.pre_op_xdata[i];
+                        xdata = local->transaction.changelog_xdata[i];
                         ia_type = inode->ia_type;
                 }
 
@@ -1783,13 +1783,13 @@ afr_local_transaction_cleanup (afr_local_t *local, xlator_t *this)
         GF_FREE (local->transaction.pre_op);
 
         GF_FREE (local->transaction.pre_op_sources);
-        if (local->transaction.pre_op_xdata) {
+        if (local->transaction.changelog_xdata) {
                 for (i = 0; i < priv->child_count; i++) {
-                        if (!local->transaction.pre_op_xdata[i])
+                        if (!local->transaction.changelog_xdata[i])
                                 continue;
-                        dict_unref (local->transaction.pre_op_xdata[i]);
+                        dict_unref (local->transaction.changelog_xdata[i]);
                 }
-                GF_FREE (local->transaction.pre_op_xdata);
+                GF_FREE (local->transaction.changelog_xdata);
         }
 
         GF_FREE (local->transaction.eager_lock);
@@ -5559,10 +5559,10 @@ afr_transaction_local_init (afr_local_t *local, xlator_t *this)
         if (!local->transaction.pre_op)
                 goto out;
 
-        local->transaction.pre_op_xdata =
-                GF_CALLOC (sizeof (*local->transaction.pre_op_xdata),
+        local->transaction.changelog_xdata =
+                GF_CALLOC (sizeof (*local->transaction.changelog_xdata),
                            priv->child_count, gf_afr_mt_dict_t);
-        if (!local->transaction.pre_op_xdata)
+        if (!local->transaction.changelog_xdata)
                 goto out;
 
         if (priv->arbiter_count == 1) {
diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index b590a1f5d51..554fb5d0458 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -338,9 +338,9 @@ afr_compute_pre_op_sources (call_frame_t *frame, xlator_t *this)
         matrix = ALLOC_MATRIX (priv->child_count, int);
 
         for (i = 0; i < priv->child_count; i++) {
-                if (!local->transaction.pre_op_xdata[i])
+                if (!local->transaction.changelog_xdata[i])
                         continue;
-                xdata = local->transaction.pre_op_xdata[i];
+                xdata = local->transaction.changelog_xdata[i];
                 afr_selfheal_fill_matrix (this, matrix, i, idx, xdata);
         }
 
@@ -357,13 +357,6 @@ afr_compute_pre_op_sources (call_frame_t *frame, xlator_t *this)
                 for (j = 0; j < priv->child_count; j++)
                         if (matrix[i][j] != 0)
                                 local->transaction.pre_op_sources[j] = 0;
-
-        /*We don't need the xattrs any more. */
-        for (i = 0; i < priv->child_count; i++)
-                if (local->transaction.pre_op_xdata[i]) {
-                        dict_unref (local->transaction.pre_op_xdata[i]);
-                        local->transaction.pre_op_xdata[i] = NULL;
-                }
 }
 
 gf_boolean_t
@@ -1211,7 +1204,7 @@ afr_changelog_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         }
 
         if (xattr)
-                local->transaction.pre_op_xdata[child_index] = dict_ref (xattr);
+                local->transaction.changelog_xdata[child_index] = dict_ref (xattr);
 
         call_count = afr_frame_return (frame);
 
@@ -1659,6 +1652,13 @@ afr_changelog_do (call_frame_t *frame, xlator_t *this, dict_t *xattr,
 	local = frame->local;
 	priv = this->private;
 
+        for (i = 0; i < priv->child_count; i++) {
+                if (local->transaction.changelog_xdata[i]) {
+                        dict_unref (local->transaction.changelog_xdata[i]);
+                        local->transaction.changelog_xdata[i] = NULL;
+                }
+        }
+
         ret = afr_changelog_prepare (this, frame, &call_count, changelog_resume,
                                      op, &xdata, &newloc_xdata);
 
diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index 91825aa94ea..db6f61eb4bd 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -748,8 +748,8 @@ typedef struct _afr_local {
 
                 unsigned char   *pre_op;
 
-                /* For arbiter configuration only. */
-                dict_t **pre_op_xdata;
+                /* Changelog xattr dict for [f]xattrop*/
+                dict_t **changelog_xdata;
                 unsigned char *pre_op_sources;
 
 		/* @failed_subvols: subvolumes on which a pre-op or a