diff --git a/repair/incore.h b/repair/incore.h
index 5b29d5d1efd8..6564e0d38963 100644
--- a/repair/incore.h
+++ b/repair/incore.h
@@ -282,6 +282,7 @@ typedef struct ino_tree_node  {
 		parent_list_t	*plist;		/* phases 2-5 */
 	} ino_un;
 	uint8_t			*ftypes;	/* phases 3,6 */
+	pthread_mutex_t		lock;
 } ino_tree_node_t;
 
 #define INOS_PER_IREC	(sizeof(uint64_t) * NBBY)
@@ -412,7 +413,9 @@ next_free_ino_rec(ino_tree_node_t *ino_rec)
  */
 static inline void add_inode_refchecked(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_un.ex_data->ino_processed |= IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline int is_inode_refchecked(struct ino_tree_node *irec, int offset)
@@ -438,12 +441,16 @@ static inline int is_inode_confirmed(struct ino_tree_node *irec, int offset)
  */
 static inline void set_inode_isadir(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_isa_dir |= IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline void clear_inode_isadir(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_isa_dir &= ~IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline int inode_isadir(struct ino_tree_node *irec, int offset)
@@ -456,15 +463,19 @@ static inline int inode_isadir(struct ino_tree_node *irec, int offset)
  */
 static inline void set_inode_free(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	set_inode_confirmed(irec, offset);
 	irec->ir_free |= XFS_INOBT_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 
 }
 
 static inline void set_inode_used(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	set_inode_confirmed(irec, offset);
 	irec->ir_free &= ~XFS_INOBT_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline int is_inode_free(struct ino_tree_node *irec, int offset)
@@ -477,7 +488,9 @@ static inline int is_inode_free(struct ino_tree_node *irec, int offset)
  */
 static inline void set_inode_sparse(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ir_sparse |= XFS_INOBT_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline bool is_inode_sparse(struct ino_tree_node *irec, int offset)
@@ -490,12 +503,16 @@ static inline bool is_inode_sparse(struct ino_tree_node *irec, int offset)
  */
 static inline void set_inode_was_rl(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_was_rl |= IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline void clear_inode_was_rl(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_was_rl &= ~IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline int inode_was_rl(struct ino_tree_node *irec, int offset)
@@ -508,12 +525,16 @@ static inline int inode_was_rl(struct ino_tree_node *irec, int offset)
  */
 static inline void set_inode_is_rl(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_is_rl |= IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline void clear_inode_is_rl(struct ino_tree_node *irec, int offset)
 {
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_is_rl &= ~IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 static inline int inode_is_rl(struct ino_tree_node *irec, int offset)
@@ -546,7 +567,9 @@ static inline int is_inode_reached(struct ino_tree_node *irec, int offset)
 static inline void add_inode_reached(struct ino_tree_node *irec, int offset)
 {
 	add_inode_ref(irec, offset);
+	pthread_mutex_lock(&irec->lock);
 	irec->ino_un.ex_data->ino_reached |= IREC_MASK(offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 /*
diff --git a/repair/incore_ino.c b/repair/incore_ino.c
index 82956ae93005..299e4f949e5e 100644
--- a/repair/incore_ino.c
+++ b/repair/incore_ino.c
@@ -91,6 +91,7 @@ void add_inode_ref(struct ino_tree_node *irec, int ino_offset)
 {
 	ASSERT(irec->ino_un.ex_data != NULL);
 
+	pthread_mutex_lock(&irec->lock);
 	switch (irec->nlink_size) {
 	case sizeof(uint8_t):
 		if (irec->ino_un.ex_data->counted_nlinks.un8[ino_offset] < 0xff) {
@@ -112,6 +113,7 @@ void add_inode_ref(struct ino_tree_node *irec, int ino_offset)
 	default:
 		ASSERT(0);
 	}
+	pthread_mutex_unlock(&irec->lock);
 }
 
 void drop_inode_ref(struct ino_tree_node *irec, int ino_offset)
@@ -120,6 +122,7 @@ void drop_inode_ref(struct ino_tree_node *irec, int ino_offset)
 
 	ASSERT(irec->ino_un.ex_data != NULL);
 
+	pthread_mutex_lock(&irec->lock);
 	switch (irec->nlink_size) {
 	case sizeof(uint8_t):
 		ASSERT(irec->ino_un.ex_data->counted_nlinks.un8[ino_offset] > 0);
@@ -139,6 +142,7 @@ void drop_inode_ref(struct ino_tree_node *irec, int ino_offset)
 
 	if (refs == 0)
 		irec->ino_un.ex_data->ino_reached &= ~IREC_MASK(ino_offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 uint32_t num_inode_references(struct ino_tree_node *irec, int ino_offset)
@@ -161,6 +165,7 @@ uint32_t num_inode_references(struct ino_tree_node *irec, int ino_offset)
 void set_inode_disk_nlinks(struct ino_tree_node *irec, int ino_offset,
 		uint32_t nlinks)
 {
+	pthread_mutex_lock(&irec->lock);
 	switch (irec->nlink_size) {
 	case sizeof(uint8_t):
 		if (nlinks < 0xff) {
@@ -182,6 +187,7 @@ void set_inode_disk_nlinks(struct ino_tree_node *irec, int ino_offset,
 	default:
 		ASSERT(0);
 	}
+	pthread_mutex_unlock(&irec->lock);
 }
 
 uint32_t get_inode_disk_nlinks(struct ino_tree_node *irec, int ino_offset)
@@ -253,6 +259,7 @@ alloc_ino_node(
 	irec->nlink_size = sizeof(uint8_t);
 	irec->disk_nlinks.un8 = alloc_nlink_array(irec->nlink_size);
 	irec->ftypes = alloc_ftypes_array(mp);
+	pthread_mutex_init(&irec->lock, NULL);
 	return irec;
 }
 
@@ -294,6 +301,7 @@ free_ino_tree_node(
 	}
 
 	free(irec->ftypes);
+	pthread_mutex_destroy(&irec->lock);
 	free(irec);
 }
 
@@ -600,6 +608,7 @@ set_inode_parent(
 	uint64_t		bitmask;
 	parent_entry_t		*tmp;
 
+	pthread_mutex_lock(&irec->lock);
 	if (full_ino_ex_data)
 		ptbl = irec->ino_un.ex_data->parents;
 	else
@@ -625,6 +634,7 @@ set_inode_parent(
 #endif
 		ptbl->pentries[0] = parent;
 
+		pthread_mutex_unlock(&irec->lock);
 		return;
 	}
 
@@ -642,6 +652,7 @@ set_inode_parent(
 #endif
 		ptbl->pentries[target] = parent;
 
+		pthread_mutex_unlock(&irec->lock);
 		return;
 	}
 
@@ -682,6 +693,7 @@ set_inode_parent(
 #endif
 	ptbl->pentries[target] = parent;
 	ptbl->pmask |= (1ULL << offset);
+	pthread_mutex_unlock(&irec->lock);
 }
 
 xfs_ino_t
@@ -692,6 +704,7 @@ get_inode_parent(ino_tree_node_t *irec, int offset)
 	int		i;
 	int		target;
 
+	pthread_mutex_lock(&irec->lock);
 	if (full_ino_ex_data)
 		ptbl = irec->ino_un.ex_data->parents;
 	else
@@ -709,9 +722,11 @@ get_inode_parent(ino_tree_node_t *irec, int offset)
 #ifdef DEBUG
 		ASSERT(target < ptbl->cnt);
 #endif
+		pthread_mutex_unlock(&irec->lock);
 		return(ptbl->pentries[target]);
 	}
 
+	pthread_mutex_unlock(&irec->lock);
 	return(0LL);
 }
 
