cluster/afr: Handle split-brain/all-fool xattrs for directory

In case of split-brain/all-fool xattrs perform conservative merge.
Don't treat ignorant subvol as fool.

Change-Id: I3044d388d816d79268fec170d202ef23e7d5bf1c
BUG: 765528
Signed-off-by: Pranith Kumar K <pranithk@gluster.com>
Reviewed-on: http://review.gluster.com/2674
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

6 files changed, 158 insertions, 176 deletions

diff --git a/xlators/cluster/afr/src/afr-self-heal-common.c b/xlators/cluster/afr/src/afr-self-heal-common.c
index 377c72a88f2..db39512d227 100644
--- a/xlators/cluster/afr/src/afr-self-heal-common.c
+++ b/xlators/cluster/afr/src/afr-self-heal-common.c
@@ -157,6 +157,7 @@ afr_mark_ignorant_subvols_as_pending (int32_t **pending_matrix,
 
 int
 afr_build_pending_matrix (char **pending_key, int32_t **pending_matrix,
+                          unsigned char *ignorant_subvols,
                           dict_t *xattr[], afr_transaction_type type,
                           size_t child_count)
 {
@@ -167,12 +168,6 @@ afr_build_pending_matrix (char **pending_key, int32_t **pending_matrix,
         int            i                = 0;
         int            j                = 0;
         int            k                = 0;
-        unsigned char *ignorant_subvols = NULL;
-
-        ignorant_subvols = GF_CALLOC (sizeof (*ignorant_subvols), child_count,
-                                      gf_afr_mt_char);
-        if (NULL == ignorant_subvols)
-                goto out;
 
         afr_init_pending_matrix (pending_matrix, child_count);
 
@@ -190,7 +185,8 @@ afr_build_pending_matrix (char **pending_key, int32_t **pending_matrix,
                                  * subvolume.
                                  */
 
-                                ignorant_subvols[i] = 1;
+                                if (ignorant_subvols)
+                                        ignorant_subvols[i] = 1;
                                 continue;
                         }
 
@@ -201,19 +197,14 @@ afr_build_pending_matrix (char **pending_key, int32_t **pending_matrix,
                 }
         }
 
-        afr_mark_ignorant_subvols_as_pending (pending_matrix,
-                                              ignorant_subvols,
-                                              child_count);
-        GF_FREE (ignorant_subvols);
-out:
         return ret;
 }
 
 typedef enum {
+        AFR_NODE_INVALID,
         AFR_NODE_INNOCENT,
         AFR_NODE_FOOL,
         AFR_NODE_WISE,
-        AFR_NODE_INVALID = -1,
 } afr_node_type;
 
 typedef struct {
@@ -467,23 +458,18 @@ out:
 
 int
 afr_mark_child_as_source_by_uid (int32_t *sources, struct iatt *bufs,
-                                 int32_t *valid_children, int child_count,
-                                 uint32_t uid)
+                                 int32_t *success_children,
+                                 unsigned int child_count, uint32_t uid)
 {
         int     i        = 0;
         int     nsources = 0;
         int     child    = 0;
 
-        GF_ASSERT (bufs);
-        GF_ASSERT (valid_children);
-        GF_ASSERT (sources);
-        GF_ASSERT (child_count > 0);
-
         for (i = 0; i < child_count; i++) {
-                if (-1 == valid_children[i])
-                        continue;
+                if (-1 == success_children[i])
+                        break;
 
-                child = valid_children[i];
+                child = success_children[i];
                 if (uid == bufs[child].ia_uid) {
                         sources[child] = 1;
                         nsources++;
@@ -493,21 +479,17 @@ afr_mark_child_as_source_by_uid (int32_t *sources, struct iatt *bufs,
 }
 
 int
-afr_get_child_with_lowest_uid (struct iatt *bufs, int32_t *valid_children,
-                               int child_count)
+afr_get_child_with_lowest_uid (struct iatt *bufs, int32_t *success_children,
+                               unsigned int child_count)
 {
         int     i        = 0;
         int     smallest = -1;
         int     child    = 0;
 
-        GF_ASSERT (bufs);
-        GF_ASSERT (valid_children);
-        GF_ASSERT (child_count > 0);
-
         for (i = 0; i < child_count; i++) {
-                if (-1 == valid_children[i])
-                        continue;
-                child = valid_children[i];
+                if (-1 == success_children[i])
+                        break;
+                child = success_children[i];
                 if ((smallest == -1) ||
                     (bufs[child].ia_uid < bufs[smallest].ia_uid)) {
                         smallest = child;
@@ -517,20 +499,20 @@ afr_get_child_with_lowest_uid (struct iatt *bufs, int32_t *valid_children,
 }
 
 static int
-afr_sh_mark_lowest_uid_as_source (struct iatt *bufs, int32_t *valid_children,
+afr_sh_mark_lowest_uid_as_source (struct iatt *bufs, int32_t *success_children,
                                   int child_count, int32_t *sources)
 {
         int   nsources              = 0;
         int   smallest              = 0;
 
-        smallest = afr_get_child_with_lowest_uid (bufs, valid_children,
+        smallest = afr_get_child_with_lowest_uid (bufs, success_children,
                                                   child_count);
         if (smallest < 0) {
                 nsources = -1;
                 goto out;
         }
         nsources = afr_mark_child_as_source_by_uid (sources, bufs,
-                                                    valid_children, child_count,
+                                                    success_children, child_count,
                                                     bufs[smallest].ia_uid);
 out:
         return nsources;
@@ -560,7 +542,7 @@ afr_get_character_str (afr_node_type type)
 
 afr_node_type
 afr_find_child_character_type (int32_t *pending_row, int32_t child,
-                               int32_t child_count, const char *xlator_name)
+                               unsigned int child_count)
 {
         afr_node_type type = AFR_NODE_INVALID;
 
@@ -574,11 +556,6 @@ afr_find_child_character_type (int32_t *pending_row, int32_t child,
                 type = AFR_NODE_FOOL;
         else if (afr_sh_is_wise (pending_row, child, child_count))
                 type = AFR_NODE_WISE;
-        else
-                GF_ASSERT (0);
-
-        gf_log (xlator_name, GF_LOG_DEBUG, "child %d character %s",
-                child, afr_get_character_str (type));
         return type;
 }
 
@@ -586,43 +563,76 @@ int
 afr_build_sources (xlator_t *this, dict_t **xattr, struct iatt *bufs,
                    int32_t **pending_matrix, int32_t *sources,
                    int32_t *success_children, afr_transaction_type type,
-                   afr_source_flags_t *flags)
+                   int32_t *subvol_status, gf_boolean_t ignore_ignorant)
 {
         afr_private_t           *priv = NULL;
         afr_self_heal_type      sh_type    = AFR_SELF_HEAL_INVALID;
         int                     nsources   = -1;
+        unsigned char           *ignorant_subvols = NULL;
+        unsigned int            child_count = 0;
 
         priv = this->private;
+        child_count = priv->child_count;
 
         if (afr_get_children_count (success_children, priv->child_count) == 0)
                 goto out;
 
+        if (!ignore_ignorant) {
+                ignorant_subvols = GF_CALLOC (sizeof (*ignorant_subvols),
+                                              child_count, gf_afr_mt_char);
+                if (NULL == ignorant_subvols)
+                        goto out;
+        }
+
         afr_build_pending_matrix (priv->pending_key, pending_matrix,
-                                  xattr, type, priv->child_count);
+                                  ignorant_subvols, xattr, type,
+                                  priv->child_count);
 
+        if (!ignore_ignorant)
+                afr_mark_ignorant_subvols_as_pending (pending_matrix,
+                                                      ignorant_subvols,
+                                                      priv->child_count);
         sh_type = afr_self_heal_type_for_transaction (type);
         if (AFR_SELF_HEAL_INVALID == sh_type)
                 goto out;
 
         afr_sh_print_pending_matrix (pending_matrix, this);
 
-        nsources = afr_mark_sources (sources, pending_matrix, bufs,
-                                     priv->child_count, sh_type,
-                                     success_children, this->name, flags);
+        nsources = afr_mark_sources (this, sources, pending_matrix, bufs,
+                                     sh_type, success_children, subvol_status);
 out:
+        GF_FREE (ignorant_subvols);
         return nsources;
 }
 
 void
-afr_mark_valid_children_sources (int32_t *sources, int32_t *valid_children,
-                                 unsigned int child_count)
+afr_find_character_types (afr_node_character *characters,
+                          int32_t **pending_matrix, int32_t *success_children,
+                          unsigned int child_count)
+{
+        afr_node_type type  = AFR_NODE_INVALID;
+        int           child = 0;
+        int           i     = 0;
+
+        for (i = 0; i < child_count; i++) {
+                child = success_children[i];
+                if (child == -1)
+                        break;
+                type = afr_find_child_character_type (pending_matrix[child],
+                                                      child, child_count);
+                characters[child].type = type;
+        }
+}
+
+void
+afr_mark_success_children_sources (int32_t *sources, int32_t *success_children,
+                                   unsigned int child_count)
 {
         int i = 0;
-        memset (sources, 0, sizeof (*sources) * child_count);
         for (i = 0; i < child_count; i++) {
-                if (valid_children[i] == -1)
+                if (success_children[i] == -1)
                         break;
-                sources[valid_children[i]] = 1;
+                sources[success_children[i]] = 1;
         }
 }
 
@@ -646,23 +656,23 @@ afr_mark_valid_children_sources (int32_t *sources, int32_t *valid_children,
  * a split-brain. If one wise node refers to the other but the other doesn't
  * refer back, the referrer is a source.
  *
- * All fools are sinks, unless there are no 'wise' nodes. if 'allfools' is NULL,
- * biggest fool(s) is/are marked as source.
+ * All fools are sinks, unless there are no 'wise' nodes. In that case,
+ * one of the fools is made a source.
  */
 
 int
-afr_mark_sources (int32_t *sources, int32_t **pending_matrix, struct iatt *bufs,
-                  int32_t child_count, afr_self_heal_type type,
-                  int32_t *valid_children, const char *xlator_name,
-                  afr_source_flags_t *flags)
+afr_mark_sources (xlator_t *this, int32_t *sources, int32_t **pending_matrix,
+                  struct iatt *bufs, afr_self_heal_type type,
+                  int32_t *success_children, int32_t *subvol_status)
 {
         /* stores the 'characters' (innocent, fool, wise) of the nodes */
-
         afr_node_character *characters =  NULL;
-        int            i              = 0;
-        int            nsources       = -1;
-        xlator_t      *this           = NULL;
+        int                nsources    = -1;
+        unsigned int       child_count = 0;
+        afr_private_t      *priv       = NULL;
 
+        priv = this->private;
+        child_count = priv->child_count;
         characters = GF_CALLOC (sizeof (afr_node_character),
                                 child_count, gf_afr_mt_afr_node_character);
         if (!characters)
@@ -671,26 +681,14 @@ afr_mark_sources (int32_t *sources, int32_t **pending_matrix, struct iatt *bufs,
         this = THIS;
 
         /* start clean */
-        for (i = 0; i < child_count; i++) {
-                sources[i] = 0;
-        }
-
+        memset (sources, 0, sizeof (*sources) * child_count);
         nsources = 0;
-        for (i = 0; i < child_count; i++) {
-                characters[i].type =
-                        afr_find_child_character_type (pending_matrix[i], i,
-                                                       child_count,
-                                                       xlator_name);
-                if (AFR_NODE_INVALID == characters[i].type)
-                        gf_log (xlator_name, GF_LOG_WARNING,
-                                "child %d had invalid xattrs", i);
-        }
-
-        if ((type == AFR_SELF_HEAL_METADATA)
-            && afr_sh_all_nodes_innocent (characters, child_count)) {
-
-                nsources = afr_sh_mark_lowest_uid_as_source (bufs,
-                                                             valid_children,
+        afr_find_character_types (characters, pending_matrix, success_children,
+                                  child_count);
+        if (afr_sh_all_nodes_innocent (characters, child_count)) {
+                if (type == AFR_SELF_HEAL_METADATA)
+                        nsources = afr_sh_mark_lowest_uid_as_source (bufs,
+                                                             success_children,
                                                              child_count,
                                                              sources);
                 goto out;
@@ -700,24 +698,17 @@ afr_mark_sources (int32_t *sources, int32_t **pending_matrix, struct iatt *bufs,
                 afr_sh_compute_wisdom (pending_matrix, characters, child_count);
 
                 if (afr_sh_wise_nodes_conflict (characters, child_count)) {
-                        /* split-brain */
-                        gf_log (this->name, GF_LOG_INFO,
-                                "split-brain possible, no source detected");
-                        if (flags)
-                                *flags |= AFR_SPLIT_BRAIN;
+                        if (subvol_status)
+                                *subvol_status |= SPLIT_BRAIN;
                         nsources = -1;
-
                 } else {
                         nsources = afr_sh_mark_wisest_as_sources (sources,
                                                                   characters,
                                                                   child_count);
                 }
         } else {
-                if (flags) {
-                        *flags |= AFR_ALL_FOOLS;
-                        nsources = -1;
-                        goto out;
-                }
+                if (subvol_status)
+                        *subvol_status |= ALL_FOOLS;
                 nsources = afr_mark_biggest_of_fools_as_source (sources,
                                                                 pending_matrix,
                                                                 characters,
@@ -726,10 +717,9 @@ afr_mark_sources (int32_t *sources, int32_t **pending_matrix, struct iatt *bufs,
 
 out:
         if (nsources == 0)
-                afr_mark_valid_children_sources (sources, valid_children,
-                                                 child_count);
-        if (characters)
-                GF_FREE (characters);
+                afr_mark_success_children_sources (sources, success_children,
+                                                   child_count);
+        GF_FREE (characters);
 
         gf_log (this->name, GF_LOG_DEBUG, "Number of sources: %d", nsources);
         return nsources;
@@ -1261,7 +1251,8 @@ afr_sh_missing_entries_lookup_done (call_frame_t *frame, xlator_t *this,
         nsources = afr_build_sources (this, sh->xattr, sh->buf,
                                       sh->pending_matrix, sh->sources,
                                       sh->child_success,
-                                      afr_transaction_type_get (ia_type), NULL);
+                                      afr_transaction_type_get (ia_type),
+                                      NULL, _gf_false);
         if (nsources < 0) {
                 gf_log (this->name, GF_LOG_INFO, "No sources for dir of %s,"
                         " in missing entry self-heal, continuing with the rest"
@@ -1686,13 +1677,13 @@ static void
 afr_sh_find_fresh_parents (call_frame_t *frame, xlator_t *this,
                            int32_t op_ret, int32_t op_errno)
 {
-        afr_self_heal_t    *sh  = NULL;
-        afr_private_t      *priv = NULL;
-        afr_local_t        *local = NULL;
-        int                enoent_count = 0;
-        int                nsources = 0;
-        int                source  = -1;
-        afr_source_flags_t flags = 0;
+        afr_self_heal_t *sh  = NULL;
+        afr_private_t   *priv = NULL;
+        afr_local_t     *local = NULL;
+        int             enoent_count = 0;
+        int             nsources = 0;
+        int             source  = -1;
+        int32_t         subvol_status = 0;
 
         local = frame->local;
         sh = &local->self_heal;
@@ -1722,22 +1713,22 @@ afr_sh_find_fresh_parents (call_frame_t *frame, xlator_t *this,
         nsources = afr_build_sources (this, sh->xattr, sh->buf,
                                       sh->pending_matrix, sh->sources,
                                       sh->child_success,
-                                      AFR_ENTRY_TRANSACTION, &flags);
-        if ((nsources < 0) && !flags) {
-                gf_log (this->name, GF_LOG_ERROR, "No sources for dir of %s,"
-                        " in missing entry self-heal, aborting self-heal",
-                        local->loc.path);
+                                      AFR_ENTRY_TRANSACTION, &subvol_status,
+                                      _gf_true);
+        if ((subvol_status & ALL_FOOLS) ||
+            (subvol_status & SPLIT_BRAIN)) {
+                gf_log (this->name, GF_LOG_INFO, "%s: Performing conservative "
+                        "merge", sh->parent_loc.path);
+                afr_mark_success_children_sources (sh->sources,
+                                                   sh->child_success,
+                                                   priv->child_count);
+        } else if (nsources < 0) {
+                gf_log (this->name, GF_LOG_ERROR, "No sources for dir "
+                        "of %s, in missing entry self-heal, aborting "
+                        "self-heal", local->loc.path);
                 goto out;
         }
 
-        //if allfools/split-brain give the behavior of missing entry creation
-        if (flags) {
-                gf_log (this->name, GF_LOG_DEBUG, "%s: All subvols pending so "
-                        "do missing entry creation", local->loc.path);
-                afr_mark_valid_children_sources (sh->sources, sh->child_success,
-                                                 priv->child_count);
-        }
-
         source = afr_sh_select_source (sh->sources, priv->child_count);
         if (source == -1) {
                 GF_ASSERT (0);
diff --git a/xlators/cluster/afr/src/afr-self-heal-common.h b/xlators/cluster/afr/src/afr-self-heal-common.h
index b313c17e984..1e325685d57 100644
--- a/xlators/cluster/afr/src/afr-self-heal-common.h
+++ b/xlators/cluster/afr/src/afr-self-heal-common.h
@@ -34,11 +34,6 @@ typedef enum {
         AFR_LOOKUP_FAIL_MISSING_GFIDS = 2,
 } afr_lookup_flags_t;
 
-typedef enum {
-        AFR_SPLIT_BRAIN = 1,
-        AFR_ALL_FOOLS =2
-} afr_source_flags_t;
-
 int
 afr_sh_select_source (int sources[], int child_count);
 
@@ -53,6 +48,7 @@ afr_sh_print_pending_matrix (int32_t *pending_matrix[], xlator_t *this);
 
 int
 afr_build_pending_matrix (char **pending_key, int32_t **pending_matrix,
+                          unsigned char *ignorant_subvols,
                           dict_t *xattr[], afr_transaction_type type,
                           size_t child_count);
 
@@ -62,10 +58,9 @@ afr_sh_pending_to_delta (afr_private_t *priv, dict_t **xattr,
                          int child_count, afr_transaction_type type);
 
 int
-afr_mark_sources (int32_t *sources, int32_t **pending_matrix, struct iatt *bufs,
-                  int32_t child_count, afr_self_heal_type type,
-                  int32_t *valid_children, const char *xlator_name,
-                  afr_source_flags_t *flags);
+afr_mark_sources (xlator_t *this, int32_t *sources, int32_t **pending_matrix,
+                  struct iatt *bufs, afr_self_heal_type type,
+                  int32_t *success_children, int32_t *subvol_status);
 
 int
 afr_sh_delta_to_xattr (afr_private_t *priv,
@@ -83,10 +78,10 @@ afr_self_heal_type
 afr_self_heal_type_for_transaction (afr_transaction_type type);
 
 int
-afr_build_sources (xlator_t *xlator, dict_t **xattr, struct iatt *bufs,
+afr_build_sources (xlator_t *this, dict_t **xattr, struct iatt *bufs,
                    int32_t **pending_matrix, int32_t *sources,
                    int32_t *success_children, afr_transaction_type type,
-                   afr_source_flags_t *flags);
+                   int32_t *subvol_status, gf_boolean_t ignore_ignorant);
 void
 afr_sh_common_reset (afr_self_heal_t *sh, unsigned int child_count);
 int
diff --git a/xlators/cluster/afr/src/afr-self-heal-data.c b/xlators/cluster/afr/src/afr-self-heal-data.c
index a2bc3bb5827..4aa5b9e8644 100644
--- a/xlators/cluster/afr/src/afr-self-heal-data.c
+++ b/xlators/cluster/afr/src/afr-self-heal-data.c
@@ -594,15 +594,9 @@ afr_sh_data_fix (call_frame_t *frame, xlator_t *this)
         sh = &local->self_heal;
         priv = this->private;
 
-        afr_build_pending_matrix (priv->pending_key, sh->pending_matrix,
-                                  sh->xattr, AFR_DATA_TRANSACTION,
-                                  priv->child_count);
-
-        afr_sh_print_pending_matrix (sh->pending_matrix, this);
-
-        nsources = afr_mark_sources (sh->sources, sh->pending_matrix, sh->buf,
-                                     priv->child_count, AFR_SELF_HEAL_DATA,
-                                     sh->child_success, this->name, NULL);
+         nsources = afr_build_sources (this, sh->xattr, sh->buf, sh->pending_matrix,
+                                       sh->sources, sh->child_success,
+                                       AFR_DATA_TRANSACTION, NULL, _gf_false);
 
         if (nsources == 0) {
                 gf_log (this->name, GF_LOG_DEBUG,
@@ -711,7 +705,7 @@ static int
 afr_select_read_child_from_policy (int32_t *sources, int32_t child_count,
                                    int32_t prev_read_child,
                                    int32_t config_read_child,
-                                   int32_t *valid_children)
+                                   int32_t *success_children)
 {
         int32_t                  read_child = -1;
         int                      i          = 0;
@@ -729,7 +723,7 @@ afr_select_read_child_from_policy (int32_t *sources, int32_t child_count,
                 goto out;
 
         for (i = 0; i < child_count; i++) {
-                read_child = valid_children[i];
+                read_child = success_children[i];
                 if (read_child < 0)
                         break;
                 if (_gf_true == afr_is_fresh_read_child (sources, child_count,
@@ -796,17 +790,17 @@ afr_lookup_select_read_child_by_txn_type (xlator_t *this, afr_local_t *local,
         int                      ret        = -1;
         int32_t                  **pending_matrix = NULL;
         int32_t                  *sources         = NULL;
-        int32_t                  *valid_children  = NULL;
+        int32_t                  *success_children  = NULL;
         struct iatt              *bufs            = NULL;
         int32_t                  nsources         = 0;
         int32_t                  prev_read_child  = -1;
         int32_t                  config_read_child = -1;
+        int32_t                  subvol_status = 0;
         afr_self_heal_t          *sh = NULL;
-        afr_self_heal_type       sh_type = AFR_SELF_HEAL_INVALID;
 
         priv = this->private;
         bufs = local->cont.lookup.bufs;
-        valid_children = local->cont.lookup.child_success;
+        success_children = local->cont.lookup.child_success;
         sh = &local->self_heal;
 
         pending_matrix = afr_create_pending_matrix (priv->child_count);
@@ -815,16 +809,12 @@ afr_lookup_select_read_child_by_txn_type (xlator_t *this, afr_local_t *local,
 
         sources = local->cont.lookup.sources;
         memset (sources, 0, sizeof (*sources) * priv->child_count);
-        afr_build_pending_matrix (priv->pending_key, pending_matrix,
-                                  xattr, txn_type, priv->child_count);
-
-        sh_type = afr_self_heal_type_for_transaction (txn_type);
-        if (AFR_SELF_HEAL_INVALID == sh_type)
-                goto out;
-
-        nsources = afr_mark_sources (sources, pending_matrix, bufs,
-                                     priv->child_count, sh_type,
-                                     valid_children, this->name, NULL);
+        nsources = afr_build_sources (this, xattr, bufs, pending_matrix,
+                                      sources, success_children, txn_type,
+                                      &subvol_status, _gf_false);
+        if (subvol_status & SPLIT_BRAIN)
+                gf_log (this->name, GF_LOG_WARNING, "%s: Possible split-brain",
+                        local->loc.path);
         if (nsources < 0) {
                 ret = -1;
                 goto out;
@@ -836,7 +826,7 @@ afr_lookup_select_read_child_by_txn_type (xlator_t *this, afr_local_t *local,
                                                         priv->child_count,
                                                         prev_read_child,
                                                         config_read_child,
-                                                        valid_children);
+                                                        success_children);
         ret = 0;
 out:
         afr_destroy_pending_matrix (pending_matrix, priv->child_count);
diff --git a/xlators/cluster/afr/src/afr-self-heal-entry.c b/xlators/cluster/afr/src/afr-self-heal-entry.c
index 161b870f509..c7a4c2b2897 100644
--- a/xlators/cluster/afr/src/afr-self-heal-entry.c
+++ b/xlators/cluster/afr/src/afr-self-heal-entry.c
@@ -1602,7 +1602,7 @@ afr_sh_entry_impunge_create (call_frame_t *impunge_frame, xlator_t *this,
 }
 
 gf_boolean_t
-afr_sh_need_recreate (afr_self_heal_t *impunge_sh, int *sources,
+afr_sh_need_recreate (afr_self_heal_t *impunge_sh,
                       unsigned int child, unsigned int child_count)
 {
         int32_t         *success_children = NULL;
@@ -1610,7 +1610,6 @@ afr_sh_need_recreate (afr_self_heal_t *impunge_sh, int *sources,
 
         GF_ASSERT (impunge_sh->impunging_entry_mode);
         GF_ASSERT (impunge_sh->child_errno);
-        GF_ASSERT (sources);
 
         success_children = impunge_sh->child_success;
         if (child == impunge_sh->active_source) {
@@ -1638,7 +1637,7 @@ afr_sh_recreate_count (afr_self_heal_t *impunge_sh, int *sources,
         int             i = 0;
 
         for (i = 0; i < child_count; i++) {
-                if (afr_sh_need_recreate (impunge_sh, sources, i, child_count))
+                if (afr_sh_need_recreate (impunge_sh, i, child_count))
                         count++;
         }
 
@@ -1673,8 +1672,7 @@ afr_sh_entry_call_impunge_recreate (call_frame_t *impunge_frame,
         GF_ASSERT (recreate_count);
         impunge_local->call_count = recreate_count;
         for (i = 0; i < priv->child_count; i++) {
-                if (afr_sh_need_recreate (impunge_sh, sh->sources, i,
-                                          priv->child_count)) {
+                if (afr_sh_need_recreate (impunge_sh, i, priv->child_count)) {
                         (void)afr_sh_entry_impunge_create (impunge_frame, this,
                                                            i, buf,
                                                            postparent);
@@ -2135,12 +2133,12 @@ void
 afr_sh_entry_fix (call_frame_t *frame, xlator_t *this,
                   int32_t op_ret, int32_t op_errno)
 {
-        afr_local_t        *local = NULL;
-        afr_self_heal_t    *sh = NULL;
-        afr_private_t      *priv = NULL;
-        afr_source_flags_t flags = 0;
-
-        int nsources = 0;
+        afr_local_t     *local = NULL;
+        afr_self_heal_t *sh = NULL;
+        afr_private_t   *priv = NULL;
+        int              source = 0;
+        int              nsources = 0;
+        int32_t          subvol_status = 0;
 
         local = frame->local;
         sh = &local->self_heal;
@@ -2158,26 +2156,30 @@ afr_sh_entry_fix (call_frame_t *frame, xlator_t *this,
                 goto heal;
         }
 
-        afr_build_pending_matrix (priv->pending_key, sh->pending_matrix,
-                                  sh->xattr, AFR_ENTRY_TRANSACTION,
-                                  priv->child_count);
-
-        afr_sh_print_pending_matrix (sh->pending_matrix, this);
-
-        nsources = afr_mark_sources (sh->sources, sh->pending_matrix, sh->buf,
-                                     priv->child_count, AFR_SELF_HEAL_ENTRY,
-                                     sh->child_success, this->name, &flags);
-
-        if (nsources == 0) {
+        nsources = afr_build_sources (this, sh->xattr, sh->buf,
+                                      sh->pending_matrix, sh->sources,
+                                      sh->child_success,
+                                      AFR_ENTRY_TRANSACTION, &subvol_status,
+                                      _gf_true);
+        if ((subvol_status & ALL_FOOLS) ||
+            (subvol_status & SPLIT_BRAIN)) {
+                gf_log (this->name, GF_LOG_INFO, "%s: Performing conservative "
+                        "merge", local->loc.path);
+                source = -1;
+                memset (sh->sources, 0,
+                        sizeof (*sh->sources) * priv->child_count);
+        } else if (nsources == 0) {
                 gf_log (this->name, GF_LOG_TRACE,
                         "No self-heal needed for %s",
                         local->loc.path);
 
                 afr_sh_entry_finish (frame, this);
                 return;
+        } else {
+                source = afr_sh_select_source (sh->sources, priv->child_count);
         }
 
-        sh->source = afr_sh_select_source (sh->sources, priv->child_count);
+        sh->source = source;
 
 heal:
         afr_sh_entry_sync_prepare (frame, this);
diff --git a/xlators/cluster/afr/src/afr-self-heal-metadata.c b/xlators/cluster/afr/src/afr-self-heal-metadata.c
index 9b920eb159f..0dc55593722 100644
--- a/xlators/cluster/afr/src/afr-self-heal-metadata.c
+++ b/xlators/cluster/afr/src/afr-self-heal-metadata.c
@@ -480,7 +480,7 @@ afr_sh_metadata_fix (call_frame_t *frame, xlator_t *this,
         nsources = afr_build_sources (this, sh->xattr, sh->buf,
                                       sh->pending_matrix, sh->sources,
                                       sh->child_success,
-                                      AFR_METADATA_TRANSACTION, NULL);
+                                      AFR_METADATA_TRANSACTION, NULL, _gf_false);
         if (nsources == 0) {
                 gf_log (this->name, GF_LOG_TRACE,
                         "No self-heal needed for %s",
diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index f29dcae4121..1e3592f658b 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -221,6 +221,10 @@ typedef struct {
         call_frame_t *sh_frame;
 } afr_self_heal_t;
 
+typedef enum {
+        SPLIT_BRAIN = 1,
+        ALL_FOOLS = 2
+} afr_subvol_status_t;
 
 typedef enum {
         AFR_DATA_TRANSACTION,          /* truncate, write, ... */