diff --git a/blockstore_flush.cpp b/blockstore_flush.cpp
index 505864e3..071dcbd5 100644
--- a/blockstore_flush.cpp
+++ b/blockstore_flush.cpp
@@ -207,7 +207,7 @@ bool journal_flusher_co::loop()
                     for (; it != v.end(); it++)
                         if (it->offset >= offset)
                             break;
-                    if (it == v.end() || it->offset > offset)
+                    if (it == v.end() || it->offset > offset && it->len > 0)
                     {
                         submit_offset = dirty_it->second.location + offset - dirty_it->second.offset;
                         submit_len = it == v.end() || it->offset >= end_offset ? end_offset-offset : it->offset-offset;
diff --git a/blockstore_read.cpp b/blockstore_read.cpp
index 11df30f0..5f941377 100644
--- a/blockstore_read.cpp
+++ b/blockstore_read.cpp
@@ -3,6 +3,11 @@
 int blockstore_impl_t::fulfill_read_push(blockstore_op_t *op, void *buf, uint64_t offset, uint64_t len,
     uint32_t item_state, uint64_t item_version)
 {
+    if (!len)
+    {
+        // Zero-length version - skip
+        return 1;
+    }
     if (IS_IN_FLIGHT(item_state))
     {
         // Pause until it's written somewhere
diff --git a/blockstore_write.cpp b/blockstore_write.cpp
index be4de07e..2d386b2a 100644
--- a/blockstore_write.cpp
+++ b/blockstore_write.cpp
@@ -147,7 +147,13 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
         }
         // There is sufficient space. Get SQE(s)
         BS_SUBMIT_GET_ONLY_SQE(sqe1);
-        BS_SUBMIT_GET_SQE(sqe2, data2);
+        struct io_uring_sqe *sqe2 = NULL;
+        struct ring_data_t *data2 = NULL;
+        if (op->len > 0)
+        {
+            BS_SUBMIT_GET_SQE_DECL(sqe2);
+            data2 = ((ring_data_t*)sqe2->user_data);
+        }
         // Got SQEs. Prepare journal sector write
         journal_entry_small_write *je = (journal_entry_small_write*)
             prefill_single_journal_entry(journal, JE_SMALL_WRITE, sizeof(struct journal_entry_small_write));
@@ -169,23 +175,31 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
         auto cb = [this, op](ring_data_t *data) { handle_write_event(data, op); };
         prepare_journal_sector_write(journal, sqe1, cb);
         PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 1 + journal.cur_sector;
-        // Prepare journal data write
-        if (journal.inmemory)
+        if (op->len > 0)
         {
-            // Copy data
-            memcpy(journal.buffer + journal.next_free, op->buf, op->len);
+            // Prepare journal data write
+            if (journal.inmemory)
+            {
+                // Copy data
+                memcpy(journal.buffer + journal.next_free, op->buf, op->len);
+            }
+            data2->iov = (struct iovec){ op->buf, op->len };
+            data2->callback = cb;
+            my_uring_prep_writev(
+                sqe2, journal.fd, &data2->iov, 1, journal.offset + journal.next_free
+            );
+            PRIV(op)->pending_ops = 2;
+        }
+        else
+        {
+            // Zero-length overwrite. Allowed to bump object version in EC placement groups without actually writing data
+            PRIV(op)->pending_ops = 1;
         }
-        data2->iov = (struct iovec){ op->buf, op->len };
-        data2->callback = cb;
-        my_uring_prep_writev(
-            sqe2, journal.fd, &data2->iov, 1, journal.offset + journal.next_free
-        );
         dirty_it->second.location = journal.next_free;
         dirty_it->second.state = ST_J_SUBMITTED;
         journal.next_free += op->len;
         if (journal.next_free >= journal.len)
             journal.next_free = 512;
-        PRIV(op)->pending_ops = 2;
         // Remember small write as unsynced
         unsynced_small_writes.push_back((obj_ver_id){
             .oid = op->oid,
diff --git a/osd_ops.h b/osd_ops.h
index 7e4f0e8a..75d7fe0d 100644
--- a/osd_ops.h
+++ b/osd_ops.h
@@ -116,6 +116,23 @@ struct __attribute__((__packed__)) osd_reply_secondary_list_t
     uint64_t stable_count;
 };
 
+// read or write to the primary OSD
+struct __attribute__((__packed__)) osd_op_rw_t
+{
+    osd_op_header_t header;
+    // inode
+    uint64_t inode;
+    // offset
+    uint64_t offset;
+    // length
+    uint64_t len;
+};
+
+struct __attribute__((__packed__)) osd_reply_rw_t
+{
+    osd_reply_header_t header;
+};
+
 union osd_any_op_t
 {
     osd_op_header_t hdr;
@@ -124,6 +141,7 @@ union osd_any_op_t
     osd_op_secondary_sync_t sec_sync;
     osd_op_secondary_stabilize_t sec_stabilize;
     osd_op_secondary_list_t sec_list;
+    osd_op_rw_t rw;
 };
 
 union osd_any_reply_t
@@ -134,4 +152,5 @@ union osd_any_reply_t
     osd_reply_secondary_sync_t sec_sync;
     osd_reply_secondary_stabilize_t sec_stabilize;
     osd_reply_secondary_list_t sec_list;
+    osd_reply_rw_t rw;
 };