From 843b7052d24c6c61e7cf85d73fe748f1af1b2d58 Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Sat, 27 Mar 2021 23:12:33 +0300
Subject: [PATCH] Add an assertion when clearing deleted metadata entries, add
 debug details when freeing blocks

---
 src/blockstore_flush.cpp    | 17 +++++++++++++++--
 src/blockstore_init.cpp     |  5 ++++-
 src/blockstore_rollback.cpp |  3 ++-
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/src/blockstore_flush.cpp b/src/blockstore_flush.cpp
index dc94b2a35..8d9c428d5 100644
--- a/src/blockstore_flush.cpp
+++ b/src/blockstore_flush.cpp
@@ -482,6 +482,14 @@ resume_1:
         }
         if (has_delete)
         {
+            clean_disk_entry *new_entry = (clean_disk_entry*)(meta_new.buf + meta_new.pos*bs->clean_entry_size);
+            if (new_entry->oid.inode != 0 && new_entry->oid != cur.oid)
+            {
+                printf("Fatal error (metadata corruption or bug): tried to delete metadata entry %lu (%lx:%lx) while deleting %lx:%lx\n",
+                    clean_loc >> bs->block_order, new_entry->oid.inode, new_entry->oid.stripe, cur.oid.inode, cur.oid.stripe);
+                exit(1);
+            }
+            // zero out new metadata entry
             memset(meta_new.buf + meta_new.pos*bs->clean_entry_size, 0, bs->clean_entry_size);
         }
         else
@@ -775,7 +783,10 @@ void journal_flusher_co::update_clean_db()
     if (old_clean_loc != UINT64_MAX && old_clean_loc != clean_loc)
     {
 #ifdef BLOCKSTORE_DEBUG
-        printf("Free block %lu (new location is %lu)\n", old_clean_loc >> bs->block_order, clean_loc >> bs->block_order);
+        printf("Free block %lu from %lx:%lx v%lu (new location is %lu)\n",
+            old_clean_loc >> bs->block_order,
+            cur.oid.inode, cur.oid.stripe, cur.version,
+            clean_loc >> bs->block_order);
 #endif
         bs->data_alloc->set(old_clean_loc >> bs->block_order, false);
     }
@@ -784,7 +795,9 @@ void journal_flusher_co::update_clean_db()
         auto clean_it = bs->clean_db.find(cur.oid);
         bs->clean_db.erase(clean_it);
 #ifdef BLOCKSTORE_DEBUG
-        printf("Free block %lu (delete)\n", clean_loc >> bs->block_order);
+        printf("Free block %lu from %lx:%lx v%lu (delete)\n",
+            clean_loc >> bs->block_order,
+            cur.oid.inode, cur.oid.stripe, cur.version);
 #endif
         bs->data_alloc->set(clean_loc >> bs->block_order, false);
         clean_loc = UINT64_MAX;
diff --git a/src/blockstore_init.cpp b/src/blockstore_init.cpp
index ca3906f4d..4f6a238c8 100644
--- a/src/blockstore_init.cpp
+++ b/src/blockstore_init.cpp
@@ -111,7 +111,10 @@ void blockstore_init_meta::handle_entries(void* entries, unsigned count, int blo
                 {
                     // free the previous block
 #ifdef BLOCKSTORE_DEBUG
-                    printf("Free block %lu (new location is %lu)\n", clean_it->second.location >> block_order, done_cnt+i);
+                    printf("Free block %lu from %lx:%lx v%lu (new location is %lu)\n",
+                        clean_it->second.location >> block_order,
+                        clean_it->first.inode, clean_it->first.stripe, clean_it->second.version,
+                        done_cnt+i);
 #endif
                     bs->data_alloc->set(clean_it->second.location >> block_order, false);
                 }
diff --git a/src/blockstore_rollback.cpp b/src/blockstore_rollback.cpp
index 20aa1b563..0de305d9e 100644
--- a/src/blockstore_rollback.cpp
+++ b/src/blockstore_rollback.cpp
@@ -251,7 +251,8 @@ void blockstore_impl_t::erase_dirty(blockstore_dirty_db_t::iterator dirty_start,
         if (IS_BIG_WRITE(dirty_it->second.state) && dirty_it->second.location != clean_loc)
         {
 #ifdef BLOCKSTORE_DEBUG
-            printf("Free block %lu\n", dirty_it->second.location >> block_order);
+            printf("Free block %lu from %lx:%lx v%lu\n", dirty_it->second.location >> block_order,
+                dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version);
 #endif
             data_alloc->set(dirty_it->second.location >> block_order, false);
         }