cluster/thin-arbiter: Consider thin-arbiter before marking new entry changelog

If a fop to create an entry fails on one of the data brick,
we mark the pending changelog on the entry on brick for which
it was successful. This is done as part of post op phase to
make sure that entry gets healed even if it gets renamed to
some other path where its parent was not marked as bad.

As it happens as part of post op, we should consider thin-arbiter
to check if the brick, which was successful, is the good brick or not.
This will avoide split brain and other issues.

>Change-Id: I12686675be98f02f70a5186b3ed748c541514d53
>Signed-off-by: Ashish Pandey <aspandey@redhat.com>

Change-Id: I12686675be98f02f70a5186b3ed748c541514d53
updates: bz#1672314
Signed-off-by: Ashish Pandey <aspandey@redhat.com>

4 files changed, 87 insertions, 19 deletions

diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index 54889e0a9b1..f030de5e5cc 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -5694,6 +5694,7 @@ afr_local_init(afr_local_t *local, afr_private_t *priv, int32_t *op_errno)
         local->ta_child_up = priv->ta_child_up;
         local->ta_failed_subvol = AFR_CHILD_UNKNOWN;
     }
+    local->is_new_entry = _gf_false;
 
     INIT_LIST_HEAD(&local->healer);
     return 0;
diff --git a/xlators/cluster/afr/src/afr-dir-write.c b/xlators/cluster/afr/src/afr-dir-write.c
index 5725b1c5cb3..a9a8e91c898 100644
--- a/xlators/cluster/afr/src/afr-dir-write.c
+++ b/xlators/cluster/afr/src/afr-dir-write.c
@@ -365,6 +365,12 @@ afr_mark_entry_pending_changelog(call_frame_t *frame, xlator_t *this)
     if (pre_op_count == priv->child_count && !failed_count)
         return;
 
+    if (priv->thin_arbiter_count) {
+        /*Mark new entry using ta file*/
+        local->is_new_entry = _gf_true;
+        return;
+    }
+
     afr_mark_new_entry_changelog(frame, this);
 
     return;
diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index fb78c198d9c..74c55f99ec2 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -28,6 +28,12 @@ typedef enum {
 static void
 afr_lock_resume_shared(struct list_head *list);
 
+static void
+afr_post_op_handle_success(call_frame_t *frame, xlator_t *this);
+
+static void
+afr_post_op_handle_failure(call_frame_t *frame, xlator_t *this);
+
 void
 __afr_transaction_wake_shared(afr_local_t *local, struct list_head *shared);
 
@@ -660,6 +666,7 @@ afr_set_pending_dict(afr_private_t *priv, dict_t *xattr, int **pending)
 
     return ret;
 }
+
 static void
 afr_ta_dom_lock_check_and_release(afr_local_t *local, xlator_t *this)
 {
@@ -739,9 +746,9 @@ afr_ta_process_onwireq(afr_local_t *local, xlator_t *this)
             --priv->ta_on_wire_txn_count;
             UNLOCK(&priv->lock);
             if (entry->ta_failed_subvol == bad_child) {
-                afr_changelog_post_op_do(entry->transaction.frame, this);
+                afr_post_op_handle_success(entry->transaction.frame, this);
             } else {
-                afr_changelog_post_op_fail(entry->transaction.frame, this, EIO);
+                afr_post_op_handle_failure(entry->transaction.frame, this);
             }
         }
     }
@@ -1187,6 +1194,34 @@ afr_ta_post_op_done(int ret, call_frame_t *frame, void *opaque)
     return 0;
 }
 
+int **
+afr_set_changelog_xattr(afr_private_t *priv, unsigned char *pending,
+                        dict_t *xattr, afr_local_t *local)
+{
+    int **changelog = NULL;
+    int idx = 0;
+    int i;
+
+    if (local->is_new_entry == _gf_true) {
+        changelog = afr_mark_pending_changelog(priv, pending, xattr,
+                                               local->cont.dir_fop.buf.ia_type);
+    } else {
+        idx = afr_index_for_transaction_type(local->transaction.type);
+        changelog = afr_matrix_create(priv->child_count, AFR_NUM_CHANGE_LOGS);
+        if (!changelog) {
+            goto out;
+        }
+        for (i = 0; i < priv->child_count; i++) {
+            if (local->transaction.failed_subvols[i])
+                changelog[i][idx] = hton32(1);
+        }
+        afr_set_pending_dict(priv, xattr, changelog);
+    }
+
+out:
+    return changelog;
+}
+
 static int
 afr_ta_post_op_do(void *opaque)
 {
@@ -1195,13 +1230,13 @@ afr_ta_post_op_do(void *opaque)
     xlator_t *this = NULL;
     call_frame_t *txn_frame = NULL;
     dict_t *xattr = NULL;
-    int **pending = NULL;
+    unsigned char *pending = NULL;
+    int **changelog = NULL;
     int failed_subvol = -1;
     int success_subvol = -1;
     loc_t loc = {
         0,
     };
-    int idx = 0;
     int i = 0;
     int ret = 0;
 
@@ -1209,7 +1244,6 @@ afr_ta_post_op_do(void *opaque)
     txn_frame = local->transaction.frame;
     this = txn_frame->this;
     priv = this->private;
-    idx = afr_index_for_transaction_type(local->transaction.type);
 
     ret = afr_fill_ta_loc(this, &loc);
     if (ret) {
@@ -1224,22 +1258,20 @@ afr_ta_post_op_do(void *opaque)
         goto out;
     }
 
-    pending = afr_matrix_create(priv->child_count, AFR_NUM_CHANGE_LOGS);
-    if (!pending) {
-        ret = -ENOMEM;
-        goto out;
-    }
+    pending = alloca0(priv->child_count);
+
     for (i = 0; i < priv->child_count; i++) {
         if (local->transaction.failed_subvols[i]) {
-            pending[i][idx] = hton32(1);
+            pending[i] = 1;
             failed_subvol = i;
         } else {
             success_subvol = i;
         }
     }
 
-    ret = afr_set_pending_dict(priv, xattr, pending);
-    if (ret < 0)
+    changelog = afr_set_changelog_xattr(priv, pending, xattr, local);
+
+    if (!changelog)
         goto out;
 
     ret = afr_ta_post_op_lock(this, &loc);
@@ -1271,16 +1303,16 @@ out:
     if (xattr)
         dict_unref(xattr);
 
-    if (pending)
-        afr_matrix_cleanup(pending, priv->child_count);
+    if (changelog)
+        afr_matrix_cleanup(changelog, priv->child_count);
 
     loc_wipe(&loc);
 
     if (ret == 0) {
         /*Mark pending xattrs on the up data brick.*/
-        afr_changelog_post_op_do(local->transaction.frame, this);
+        afr_post_op_handle_success(local->transaction.frame, this);
     } else {
-        afr_changelog_post_op_fail(local->transaction.frame, this, -ret);
+        afr_post_op_handle_failure(local->transaction.frame, this);
     }
     return ret;
 }
@@ -1359,6 +1391,28 @@ afr_ta_fill_failed_subvol(afr_private_t *priv, afr_local_t *local)
 }
 
 static void
+afr_post_op_handle_success(call_frame_t *frame, xlator_t *this)
+{
+    afr_local_t *local = NULL;
+
+    local = frame->local;
+    if (local->is_new_entry == _gf_true) {
+        afr_mark_new_entry_changelog(frame, this);
+    }
+    afr_changelog_post_op_do(frame, this);
+
+    return;
+}
+
+static void
+afr_post_op_handle_failure(call_frame_t *frame, xlator_t *this)
+{
+    afr_changelog_post_op_fail(frame, this, EIO);
+
+    return;
+}
+
+static void
 afr_ta_decide_post_op_state(call_frame_t *frame, xlator_t *this)
 {
     afr_private_t *priv = NULL;
@@ -1380,10 +1434,12 @@ afr_ta_decide_post_op_state(call_frame_t *frame, xlator_t *this)
             /*Post releasing the notify lock, we will act on this queue*/
             break;
         case TA_INFO_IN_MEMORY_SUCCESS:
-            afr_changelog_post_op_do(frame, this);
+            afr_post_op_handle_success(frame, this);
             break;
         case TA_INFO_IN_MEMORY_FAILED:
-            afr_changelog_post_op_fail(frame, this, EIO);
+            afr_post_op_handle_failure(frame, this);
+            break;
+        default:
             break;
     }
     return;
diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index 6f8015380f0..6ddb992f448 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -880,6 +880,7 @@ typedef struct _afr_local {
     struct list_head ta_onwireq;
     afr_ta_fop_state_t fop_state;
     int ta_failed_subvol;
+    gf_boolean_t is_new_entry;
 } afr_local_t;
 
 typedef struct afr_spbc_timeout {
@@ -1320,4 +1321,8 @@ afr_ta_has_quorum(afr_private_t *priv, afr_local_t *local);
 
 void
 afr_ta_lock_release_synctask(xlator_t *this);
+
+void
+afr_mark_new_entry_changelog(call_frame_t *frame, xlator_t *this);
+
 #endif /* __AFR_H__ */