diff --git a/blockstore.h b/blockstore.h
index 02b72e95..e6f4abe7 100644
--- a/blockstore.h
+++ b/blockstore.h
@@ -129,7 +129,7 @@ struct __attribute__((__packed__)) clean_entry
     uint64_t location;
 };
 
-// 48 = 24 + 24 bytes per dirty entry in memory (obj_ver_id => dirty_entry)
+// 56 = 24 + 32 bytes per dirty entry in memory (obj_ver_id => dirty_entry)
 struct __attribute__((__packed__)) obj_ver_id
 {
     object_id oid;
@@ -148,6 +148,7 @@ struct __attribute__((__packed__)) dirty_entry
     uint64_t location; // location in either journal or data
     uint32_t offset;   // offset within stripe
     uint32_t len;      // data length
+    uint64_t journal_sector; // journal sector used for this entry
 };
 
 class oid_hash
diff --git a/blockstore_flush.cpp b/blockstore_flush.cpp
index 40604920..156a7234 100644
--- a/blockstore_flush.cpp
+++ b/blockstore_flush.cpp
@@ -289,6 +289,8 @@ resume_0:
                 flusher->syncs.erase(cur_sync);
             }
         }
+        // FIXME: Adjust clean_db and dirty_db
+        // FIXME: ...and clear part of the journal
         wait_state = 0;
         flusher->active_flushers--;
         goto resume_0;
diff --git a/blockstore_init.cpp b/blockstore_init.cpp
index 09e621d6..36195a87 100644
--- a/blockstore_init.cpp
+++ b/blockstore_init.cpp
@@ -276,6 +276,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t len)
                     break;
                 }
             }
+            bs->journal.used_sectors[total_pos]++;
             pos += je->size;
             crc32_last = je->crc32;
             if (je->type == JE_SMALL_WRITE)
@@ -292,6 +293,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t len)
                 {
                     // data is right next
                     location = done_pos + total_pos;
+                    // FIXME: OOPS. Please don't modify total_pos here
                     total_pos += je->small_write.len;
                 }
                 bs->dirty_db.emplace((obj_ver_id){
@@ -303,6 +305,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t len)
                     .location = location,
                     .offset = je->small_write.offset,
                     .len = je->small_write.len,
+                    .journal_sector = total_pos,
                 });
             }
             else if (je->type == JE_BIG_WRITE)
@@ -317,6 +320,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t len)
                     .location = je->big_write.location,
                     .offset = 0,
                     .len = bs->block_size,
+                    .journal_sector = total_pos,
                 });
             }
             else if (je->type == JE_STABLE)
@@ -351,6 +355,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t len)
                     .location = 0,
                     .offset = 0,
                     .len = 0,
+                    .journal_sector = total_pos,
                 });
             }
         }
diff --git a/blockstore_journal.h b/blockstore_journal.h
index 17e8928d..0413b63e 100644
--- a/blockstore_journal.h
+++ b/blockstore_journal.h
@@ -121,6 +121,10 @@ struct journal_t
     uint64_t sector_count;
     int cur_sector = 0;
     int in_sector_pos = 0;
+
+    // Used sector map
+    // May use ~ 80 MB per 1 GB of used journal space in the worst case
+    std::map<uint64_t, uint64_t> used_sectors;
 };
 
 struct blockstore_journal_check_t
diff --git a/blockstore_sync.cpp b/blockstore_sync.cpp
index bf3b45c3..d952078a 100644
--- a/blockstore_sync.cpp
+++ b/blockstore_sync.cpp
@@ -78,6 +78,8 @@ int blockstore::continue_sync(blockstore_operation *op)
         {
             journal_entry_big_write *je = (journal_entry_big_write*)
                 prefill_single_journal_entry(journal, JE_BIG_WRITE, sizeof(journal_entry_big_write));
+            dirty_db[*it].journal_sector = journal.sector_info[journal.cur_sector].offset;
+            journal.used_sectors[journal.sector_info[journal.cur_sector].offset]++;
             je->oid = it->oid;
             je->version = it->version;
             je->location = dirty_db[*it].location;
diff --git a/blockstore_write.cpp b/blockstore_write.cpp
index c21178cc..412caca2 100644
--- a/blockstore_write.cpp
+++ b/blockstore_write.cpp
@@ -34,6 +34,7 @@ void blockstore::enqueue_write(blockstore_operation *op)
         .location = 0,
         .offset = op->offset,
         .len = op->len,
+        .journal_sector = 0,
     });
     // Remember write as unsynced here, so external consumers could get
     // the list of dirty objects to sync just before issuing a SYNC request
@@ -122,6 +123,8 @@ int blockstore::dequeue_write(blockstore_operation *op)
         // 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));
+        dirty_it->second.journal_sector = journal.sector_info[journal.cur_sector].offset;
+        journal.used_sectors[journal.sector_info[journal.cur_sector].offset]++;
         je->oid = op->oid;
         je->version = op->version;
         je->offset = op->offset;