cluster/afr: Add afr-v1 xattr compatibility

All the special cases v1 handles and also
self-accusing pending changelog from v1 pre-op also is handled
in this patch.

Change-Id: Ie10f71633fb20276f01ecafbd728f20483e7029c
BUG: 1128721
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/8536
Reviewed-by: Ravishankar N <ravishankar@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

6 files changed, 330 insertions, 83 deletions

diff --git a/xlators/cluster/afr/src/afr-self-heal-common.c b/xlators/cluster/afr/src/afr-self-heal-common.c
index ddccc7f38ed..14a514beffa 100644
--- a/xlators/cluster/afr/src/afr-self-heal-common.c
+++ b/xlators/cluster/afr/src/afr-self-heal-common.c
@@ -287,7 +287,36 @@ afr_selfheal_extract_xattr (xlator_t *this, struct afr_reply *replies,
 	return 0;
 }
 
+void
+afr_mark_active_sinks (xlator_t *this, unsigned char *sources,
+                       unsigned char *locked_on, unsigned char *sinks)
+{
+        int i = 0;
+        afr_private_t *priv = NULL;
+
+        priv = this->private;
+
+        memset (sinks, 0, sizeof (*sinks) * priv->child_count);
+        for (i = 0; i < priv->child_count; i++) {
+                if (!sources[i] && locked_on[i])
+                        sinks[i] = 1;
+        }
+}
 
+gf_boolean_t
+afr_does_witness_exist (xlator_t *this, uint64_t *witness)
+{
+        int i = 0;
+        afr_private_t *priv = NULL;
+
+        priv = this->private;
+
+        for (i = 0; i < priv->child_count; i++) {
+                if (witness[i])
+                        return _gf_true;
+        }
+        return _gf_false;
+}
 
 /*
  * This function determines if a self-heal is required for a given inode,
@@ -309,22 +338,29 @@ afr_selfheal_extract_xattr (xlator_t *this, struct afr_reply *replies,
  */
 
 int
-afr_selfheal_find_direction (xlator_t *this, struct afr_reply *replies,
-			     afr_transaction_type type, unsigned char *locked_on,
-			     unsigned char *sources, unsigned char *sinks)
+afr_selfheal_find_direction (call_frame_t *frame, xlator_t *this,
+                             struct afr_reply *replies,
+                             afr_transaction_type type,
+                             unsigned char *locked_on, unsigned char *sources,
+                             unsigned char *sinks, uint64_t *witness)
 {
-	afr_private_t *priv = NULL;
-	int i = 0;
-	int j = 0;
-	int *dirty = NULL;
-	int **matrix = NULL;
-	char *accused = NULL;
+        afr_private_t *priv = NULL;
+        int i = 0;
+        int j = 0;
+        int *dirty = NULL; /* Denotes if dirty xattr is set */
+        int **matrix = NULL;/* Changelog matrix */
+        char *accused = NULL;/* Accused others without any self-accusal */
+        char *pending = NULL;/* Have pending operations on others */
+        char *self_accused = NULL; /* Accused itself */
 
 	priv = this->private;
 
 	dirty = alloca0 (priv->child_count * sizeof (int));
 	accused = alloca0 (priv->child_count);
+        pending = alloca0 (priv->child_count);
+        self_accused = alloca0 (priv->child_count);
 	matrix = ALLOC_MATRIX(priv->child_count, int);
+        memset (witness, 0, sizeof (*witness) * priv->child_count);
 
         if (afr_success_count (replies,
                                priv->child_count) < AFR_SH_MIN_PARTICIPANTS) {
@@ -335,11 +371,23 @@ afr_selfheal_find_direction (xlator_t *this, struct afr_reply *replies,
 	/* First construct the pending matrix for further analysis */
 	afr_selfheal_extract_xattr (this, replies, type, dirty, matrix);
 
+        /* short list all self-accused */
+        for (i = 0; i < priv->child_count; i++) {
+                if (matrix[i][i])
+                        self_accused[i] = 1;
+        }
+
 	/* Next short list all accused to exclude them from being sources */
+        /* Self-accused can't accuse others as they are FOOLs */
 	for (i = 0; i < priv->child_count; i++) {
 		for (j = 0; j < priv->child_count; j++) {
-			if (matrix[i][j])
-				accused[j] = 1;
+                        if (matrix[i][j]) {
+                                 if (!self_accused[i])
+                                         accused[j] = 1;
+
+                                 if (i != j)
+                                         pending[i] = 1;
+                         }
 		}
 	}
 
@@ -350,38 +398,47 @@ afr_selfheal_find_direction (xlator_t *this, struct afr_reply *replies,
 			sources[i] = 1;
 	}
 
-	/* Everyone accused by sources are sinks */
-	memset (sinks, 0, priv->child_count);
-	for (i = 0; i < priv->child_count; i++) {
-		if (!sources[i])
-			continue;
-		for (j = 0; j < priv->child_count; j++) {
-			if (matrix[i][j])
-				sinks[j] = 1;
-		}
-	}
+        /* Everyone accused by non-self-accused sources are sinks */
+        memset (sinks, 0, priv->child_count);
+        for (i = 0; i < priv->child_count; i++) {
+                if (!sources[i])
+                        continue;
+                if (self_accused[i])
+                        continue;
+                for (j = 0; j < priv->child_count; j++) {
+                        if (matrix[i][j])
+                                sinks[j] = 1;
+                }
+        }
 
-	/* If any source has 'dirty' bit, pick first
-	   'dirty' source and make everybody else sinks */
-	for (i = 0; i < priv->child_count; i++) {
-		if (sources[i] && dirty[i]) {
-			for (j = 0; j < priv->child_count; j++) {
-				if (j != i) {
-					sources[j] = 0;
-					sinks[j] = 1;
-				}
-			}
-			break;
-		}
-	}
+        /* For breaking ties provide with number of fops they witnessed */
 
-	/* If no sources, all locked nodes are sinks - split brain */
-	if (AFR_COUNT (sources, priv->child_count) == 0) {
-		for (i = 0; i < priv->child_count; i++) {
-			if (locked_on[i])
-				sinks[i] = 1;
-		}
-	}
+        /*
+         * count the pending fops witnessed from itself to others when it is
+         * self-accused
+         */
+        for (i = 0; i < priv->child_count; i++) {
+                if (!self_accused[i])
+                        continue;
+                for (j = 0; j < priv->child_count; j++) {
+                        if (i == j)
+                                continue;
+                        witness[i] += matrix[i][j];
+                }
+        }
+
+        /* In afr-v1 if a file is self-accused but didn't have any pending
+         * operations on others then it is similar to 'dirty' in afr-v2.
+         * Consider such cases as witness.
+         */
+        for (i = 0; i < priv->child_count; i++) {
+                if (self_accused[i] && !pending[i])
+                        witness[i] += matrix[i][i];
+        }
+
+        /* count the number of dirty fops witnessed */
+        for (i = 0; i < priv->child_count; i++)
+                witness[i] += dirty[i];
 
 	return 0;
 }
diff --git a/xlators/cluster/afr/src/afr-self-heal-data.c b/xlators/cluster/afr/src/afr-self-heal-data.c
index 74088f4bf6d..f7503faa719 100644
--- a/xlators/cluster/afr/src/afr-self-heal-data.c
+++ b/xlators/cluster/afr/src/afr-self-heal-data.c
@@ -372,21 +372,160 @@ __afr_selfheal_truncate_sinks (call_frame_t *frame, xlator_t *this,
 	return 0;
 }
 
+gf_boolean_t
+afr_has_source_witnesses (xlator_t *this, unsigned char *sources,
+                          uint64_t *witness)
+{
+        int i = 0;
+        afr_private_t *priv = NULL;
+
+        priv = this->private;
+
+        for (i = 0; i < priv->child_count; i++) {
+                if (sources[i] && witness[i])
+                        return _gf_true;
+        }
+        return _gf_false;
+}
+
+static gf_boolean_t
+afr_does_size_mismatch (xlator_t *this, unsigned char *sources,
+                        struct afr_reply *replies)
+{
+        int     i = 0;
+        afr_private_t *priv = NULL;
+        struct iatt *min = NULL;
+        struct iatt *max = NULL;
+
+        priv = this->private;
+
+        for (i = 0; i < priv->child_count; i++) {
+                if (!replies[i].valid)
+                        continue;
+
+                if (replies[i].op_ret < 0)
+                        continue;
+
+                if (!min)
+                        min = &replies[i].poststat;
+
+                if (!max)
+                        max = &replies[i].poststat;
+
+                if (min->ia_size > replies[i].poststat.ia_size)
+                        min = &replies[i].poststat;
+
+                if (max->ia_size < replies[i].poststat.ia_size)
+                        max = &replies[i].poststat;
+        }
+
+        if (min && max) {
+                if (min->ia_size != max->ia_size)
+                        return _gf_true;
+        }
+
+        return _gf_false;
+}
 /*
  * If by chance there are multiple sources with differing sizes, select
  * the largest file as the source.
  *
- * This can only happen if data was directly modified in the backend.
+ * This can happen if data was directly modified in the backend or for snapshots
  */
+
+static void
+afr_mark_largest_file_as_source (xlator_t *this, unsigned char *sources,
+                                 struct afr_reply *replies)
+{
+        int i = 0;
+        afr_private_t *priv = NULL;
+        uint64_t size = 0;
+
+        /* Find source with biggest file size */
+        priv = this->private;
+        for (i = 0; i < priv->child_count; i++) {
+                if (!sources[i])
+                        continue;
+                if (size <= replies[i].poststat.ia_size) {
+                        size = replies[i].poststat.ia_size;
+                }
+        }
+
+        /* Mark sources with less size as not source */
+        for (i = 0; i < priv->child_count; i++) {
+                if (!sources[i])
+                        continue;
+                if (size > replies[i].poststat.ia_size)
+                        sources[i] = 0;
+        }
+
+        return;
+}
+
+static void
+afr_mark_biggest_witness_as_source (xlator_t *this, unsigned char *sources,
+                                    uint64_t *witness)
+{
+        int i = 0;
+        afr_private_t *priv = NULL;
+        uint64_t biggest_witness = 0;
+
+        priv = this->private;
+        /* Find source with biggest witness count */
+        for (i = 0; i < priv->child_count; i++) {
+                if (!sources[i])
+                        continue;
+                if (biggest_witness < witness[i])
+                        biggest_witness = witness[i];
+        }
+
+        /* Mark files with less witness count as not source */
+        for (i = 0; i < priv->child_count; i++) {
+                if (!sources[i])
+                        continue;
+                if (witness[i] < biggest_witness)
+                        sources[i] = 0;
+        }
+
+        return;
+}
+
+/* This is a tie breaker function. Only one source be assigned here */
+static void
+afr_mark_newest_file_as_source (xlator_t *this, unsigned char *sources,
+                                struct afr_reply *replies)
+{
+        int i = 0;
+        afr_private_t *priv = NULL;
+        int source = -1;
+        uint32_t max_ctime = 0;
+
+        priv = this->private;
+        /* Find source with latest ctime */
+        for (i = 0; i < priv->child_count; i++) {
+                if (!sources[i])
+                        continue;
+
+                if (max_ctime <= replies[i].poststat.ia_ctime) {
+                        source = i;
+                        max_ctime = replies[i].poststat.ia_ctime;
+                }
+        }
+
+        /* Only mark one of the files as source to break ties */
+        memset (sources, 0, sizeof (*sources) * priv->child_count);
+        sources[source] = 1;
+}
+
 static int
 __afr_selfheal_data_finalize_source (xlator_t *this, unsigned char *sources,
 				     unsigned char *healed_sinks,
 				     unsigned char *locked_on,
-				     struct afr_reply *replies)
+				     struct afr_reply *replies,
+                                     uint64_t *witness)
 {
 	int i = 0;
 	afr_private_t *priv = NULL;
-	uint64_t size = 0;
 	int source = -1;
 	int sources_count = 0;
 
@@ -400,24 +539,24 @@ __afr_selfheal_data_finalize_source (xlator_t *this, unsigned char *sources,
 		return -EIO;
 	}
 
-	for (i = 0; i < priv->child_count; i++) {
-		if (!sources[i])
-			continue;
-		if (size <= replies[i].poststat.ia_size) {
-			size = replies[i].poststat.ia_size;
-			source = i;
-		}
-	}
+        /* If there are no witnesses/size-mismatches on sources we are done*/
+        if (!afr_does_size_mismatch (this, sources, replies) &&
+            !afr_has_source_witnesses (this, sources, witness))
+                goto out;
 
-	for (i = 0; i < priv->child_count; i++) {
-		if (!sources[i])
-			continue;
-		if (replies[i].poststat.ia_size < size) {
-			sources[i] = 0;
-			healed_sinks[i] = 1;
-		}
-	}
+        afr_mark_largest_file_as_source (this, sources, replies);
+        afr_mark_biggest_witness_as_source (this, sources, witness);
+        afr_mark_newest_file_as_source (this, sources, replies);
+
+out:
+        afr_mark_active_sinks (this, sources, locked_on, healed_sinks);
 
+        for (i = 0; i < priv->child_count; i++) {
+                if (sources[i]) {
+                        source = i;
+                        break;
+                }
+        }
 	return source;
 }
 
@@ -439,6 +578,7 @@ __afr_selfheal_data_prepare (call_frame_t *frame, xlator_t *this, fd_t *fd,
 	int ret = -1;
 	int source = -1;
 	afr_private_t *priv = NULL;
+        uint64_t *witness = NULL;
 
 	priv = this->private;
 
@@ -447,15 +587,16 @@ __afr_selfheal_data_prepare (call_frame_t *frame, xlator_t *this, fd_t *fd,
 	if (ret)
 		return ret;
 
-	ret = afr_selfheal_find_direction (this, replies, AFR_DATA_TRANSACTION,
-					   locked_on, sources, sinks);
+        witness = alloca0(priv->child_count * sizeof (*witness));
+	ret = afr_selfheal_find_direction (frame, this, replies,
+					   AFR_DATA_TRANSACTION,
+					   locked_on, sources, sinks, witness);
 	if (ret)
 		return ret;
 
         /* Initialize the healed_sinks[] array optimistically to
            the intersection of to-be-healed (i.e sinks[]) and
            the list of servers which are up (i.e locked_on[]).
-
            As we encounter failures in the healing process, we
            will unmark the respective servers in the healed_sinks[]
            array.
@@ -464,7 +605,7 @@ __afr_selfheal_data_prepare (call_frame_t *frame, xlator_t *this, fd_t *fd,
 
 	source = __afr_selfheal_data_finalize_source (this, sources,
                                                       healed_sinks, locked_on,
-                                                      replies);
+                                                      replies, witness);
 	if (source < 0)
 		return -EIO;
 
diff --git a/xlators/cluster/afr/src/afr-self-heal-entry.c b/xlators/cluster/afr/src/afr-self-heal-entry.c
index df6dfaaf396..3ea30a6a9d0 100644
--- a/xlators/cluster/afr/src/afr-self-heal-entry.c
+++ b/xlators/cluster/afr/src/afr-self-heal-entry.c
@@ -326,7 +326,9 @@ __afr_selfheal_entry_dirent (call_frame_t *frame, xlator_t *this, fd_t *fd,
 static int
 __afr_selfheal_entry_finalize_source (xlator_t *this, unsigned char *sources,
 				      unsigned char *healed_sinks,
-				      unsigned char *locked_on)
+                                      unsigned char *locked_on,
+                                      struct afr_reply *replies,
+                                      uint64_t *witness)
 {
 	int i = 0;
 	afr_private_t *priv = NULL;
@@ -338,7 +340,10 @@ __afr_selfheal_entry_finalize_source (xlator_t *this, unsigned char *sources,
 	sources_count = AFR_COUNT (sources, priv->child_count);
 
 	if ((AFR_CMP (locked_on, healed_sinks, priv->child_count) == 0)
-            || !sources_count) {
+            || !sources_count || afr_does_witness_exist (this, witness)) {
+
+                memset (sources, 0, sizeof (*sources) * priv->child_count);
+                afr_mark_active_sinks (this, sources, locked_on, healed_sinks);
 		return -1;
 	}
 
@@ -362,6 +367,7 @@ __afr_selfheal_entry_prepare (call_frame_t *frame, xlator_t *this, fd_t *fd,
 	int ret = -1;
 	int source = -1;
 	afr_private_t *priv = NULL;
+        uint64_t *witness = NULL;
 
 	priv = this->private;
 
@@ -370,8 +376,10 @@ __afr_selfheal_entry_prepare (call_frame_t *frame, xlator_t *this, fd_t *fd,
 	if (ret)
 		return ret;
 
-	ret = afr_selfheal_find_direction (this, replies, AFR_ENTRY_TRANSACTION,
-					   locked_on, sources, sinks);
+        witness = alloca0 (sizeof (*witness) * priv->child_count);
+	ret = afr_selfheal_find_direction (frame, this, replies,
+					   AFR_ENTRY_TRANSACTION,
+					   locked_on, sources, sinks, witness);
 	if (ret)
 		return ret;
 
@@ -386,7 +394,10 @@ __afr_selfheal_entry_prepare (call_frame_t *frame, xlator_t *this, fd_t *fd,
         AFR_INTERSECT (healed_sinks, sinks, locked_on, priv->child_count);
 
 	source = __afr_selfheal_entry_finalize_source (this, sources,
-                                                       healed_sinks, locked_on);
+                                                       healed_sinks,
+						       locked_on, replies,
+                                                       witness);
+
 	if (source < 0) {
 		/* If source is < 0 (typically split-brain), we perform a
 		   conservative merge of entries rather than erroring out */
diff --git a/xlators/cluster/afr/src/afr-self-heal-metadata.c b/xlators/cluster/afr/src/afr-self-heal-metadata.c
index b4714fe9e05..96b3262e471 100644
--- a/xlators/cluster/afr/src/afr-self-heal-metadata.c
+++ b/xlators/cluster/afr/src/afr-self-heal-metadata.c
@@ -169,7 +169,6 @@ __afr_selfheal_metadata_finalize_source (call_frame_t *frame, xlator_t *this,
 	return source;
 }
 
-
 static int
 __afr_selfheal_metadata_prepare (call_frame_t *frame, xlator_t *this, inode_t *inode,
 				 unsigned char *locked_on, unsigned char *sources,
@@ -179,6 +178,8 @@ __afr_selfheal_metadata_prepare (call_frame_t *frame, xlator_t *this, inode_t *i
 	int ret = -1;
 	int source = -1;
 	afr_private_t *priv = NULL;
+	int i = 0;
+        uint64_t *witness = NULL;
 
 	priv = this->private;
 
@@ -187,9 +188,10 @@ __afr_selfheal_metadata_prepare (call_frame_t *frame, xlator_t *this, inode_t *i
 	if (ret)
 		return ret;
 
-	ret = afr_selfheal_find_direction (this, replies,
-                                           AFR_METADATA_TRANSACTION,
-					   locked_on, sources, sinks);
+        witness = alloca0 (sizeof (*witness) * priv->child_count);
+	ret = afr_selfheal_find_direction (frame, this, replies,
+					   AFR_METADATA_TRANSACTION,
+					   locked_on, sources, sinks, witness);
 	if (ret)
 		return ret;
 
@@ -203,9 +205,28 @@ __afr_selfheal_metadata_prepare (call_frame_t *frame, xlator_t *this, inode_t *i
         */
         AFR_INTERSECT (healed_sinks, sinks, locked_on, priv->child_count);
 
+        /* If any source has witness, pick first
+         * witness source and make everybody else sinks */
+        for (i = 0; i < priv->child_count; i++) {
+                if (sources[i] && witness[i]) {
+                        source = i;
+                        break;
+                }
+        }
+
+        if (source != -1) {
+                for (i = 0; i < priv->child_count; i++) {
+                        if (i != source && sources[i]) {
+                                sources[i] = 0;
+                                healed_sinks[i] = 1;
+                        }
+                }
+        }
+
 	source = __afr_selfheal_metadata_finalize_source (frame, this, sources,
                                                           healed_sinks,
-							  locked_on, replies);
+                                                          locked_on, replies);
+
 	if (source < 0)
 		return -EIO;
 
diff --git a/xlators/cluster/afr/src/afr-self-heal-name.c b/xlators/cluster/afr/src/afr-self-heal-name.c
index c5d126185c7..af635f06d52 100644
--- a/xlators/cluster/afr/src/afr-self-heal-name.c
+++ b/xlators/cluster/afr/src/afr-self-heal-name.c
@@ -457,7 +457,9 @@ __afr_selfheal_name_do (call_frame_t *frame, xlator_t *this, inode_t *parent,
 int
 __afr_selfheal_name_finalize_source (xlator_t *this, unsigned char *sources,
 				     unsigned char *healed_sinks,
-                                     unsigned char *locked_on)
+				     unsigned char *locked_on,
+				     struct afr_reply *replies,
+                                     uint64_t *witness)
 {
 	int i = 0;
 	afr_private_t *priv = NULL;
@@ -469,7 +471,9 @@ __afr_selfheal_name_finalize_source (xlator_t *this, unsigned char *sources,
 	sources_count = AFR_COUNT (sources, priv->child_count);
 
 	if ((AFR_CMP (locked_on, healed_sinks, priv->child_count) == 0)
-            || !sources_count) {
+            || !sources_count || afr_does_witness_exist (this, witness)) {
+                memset (sources, 0, sizeof (*sources) * priv->child_count);
+                afr_mark_active_sinks (this, sources, locked_on, healed_sinks);
 		return -1;
 	}
 
@@ -483,7 +487,6 @@ __afr_selfheal_name_finalize_source (xlator_t *this, unsigned char *sources,
 	return source;
 }
 
-
 int
 __afr_selfheal_name_prepare (call_frame_t *frame, xlator_t *this, inode_t *parent,
 			     uuid_t pargfid, unsigned char *locked_on,
@@ -494,6 +497,7 @@ __afr_selfheal_name_prepare (call_frame_t *frame, xlator_t *this, inode_t *paren
 	int source = -1;
 	afr_private_t *priv = NULL;
         struct afr_reply *replies = NULL;
+        uint64_t *witness = NULL;
 
 	priv = this->private;
 
@@ -503,8 +507,10 @@ __afr_selfheal_name_prepare (call_frame_t *frame, xlator_t *this, inode_t *paren
 	if (ret)
 		goto out;
 
-	ret = afr_selfheal_find_direction (this, replies, AFR_ENTRY_TRANSACTION,
-					   locked_on, sources, sinks);
+        witness = alloca0 (sizeof (*witness) * priv->child_count);
+	ret = afr_selfheal_find_direction (frame, this, replies,
+					   AFR_ENTRY_TRANSACTION,
+					   locked_on, sources, sinks, witness);
 	if (ret)
 		goto out;
 
@@ -519,7 +525,9 @@ __afr_selfheal_name_prepare (call_frame_t *frame, xlator_t *this, inode_t *paren
         AFR_INTERSECT (healed_sinks, sinks, locked_on, priv->child_count);
 
 	source = __afr_selfheal_name_finalize_source (this, sources,
-                                                      healed_sinks, locked_on);
+                                                      healed_sinks,
+						      locked_on, replies,
+                                                      witness);
 	if (source < 0) {
 		/* If source is < 0 (typically split-brain), we perform a
 		   conservative merge of entries rather than erroring out */
diff --git a/xlators/cluster/afr/src/afr-self-heal.h b/xlators/cluster/afr/src/afr-self-heal.h
index c32ec120a50..f208e6bc813 100644
--- a/xlators/cluster/afr/src/afr-self-heal.h
+++ b/xlators/cluster/afr/src/afr-self-heal.h
@@ -136,9 +136,11 @@ afr_selfheal_unlocked_lookup_on (call_frame_t *frame, inode_t *parent,
 				 unsigned char *lookup_on, dict_t *xattr);
 
 int
-afr_selfheal_find_direction (xlator_t *this, struct afr_reply *replies,
-			     afr_transaction_type type, unsigned char *locked_on,
-			     unsigned char *sources, unsigned char *sinks);
+afr_selfheal_find_direction (call_frame_t *frame, xlator_t *this,
+                             struct afr_reply *replies,
+                             afr_transaction_type type,
+                             unsigned char *locked_on, unsigned char *sources,
+                             unsigned char *sinks, uint64_t *witness);
 
 int
 afr_selfheal_extract_xattr (xlator_t *this, struct afr_reply *replies,
@@ -189,4 +191,11 @@ afr_success_count (struct afr_reply *replies, unsigned int count);
 void
 afr_log_selfheal (uuid_t gfid, xlator_t *this, int ret, char *type,
                   int source, unsigned char *healed_sinks);
+
+void
+afr_mark_active_sinks (xlator_t *this, unsigned char *sources,
+                       unsigned char *locked_on, unsigned char *sinks);
+
+gf_boolean_t
+afr_does_witness_exist (xlator_t *this, uint64_t *witness);
 #endif /* !_AFR_SELFHEAL_H */