From dc72c843684803d4596baea58db0ecdc4e1783ab Mon Sep 17 00:00:00 2001
From: Nick Vatamaniuc <vatamane@gmail.com>
Date: Wed, 27 May 2026 14:48:47 -0400
Subject: [PATCH] Fix leaked opened db handle in smoosh

`smoosh_channel:maybe_remonitor_cpid/3` opened db and never closed it. That
left a dangling reference (monitor to it) which prevented that db handle from
becoming idle.

We noticed this after inspecting dangling deleted fd handles which were still
left open by something. That something turned to be smoosh_channel gen_server.
---
 src/smoosh/src/smoosh_channel.erl | 38 +++++++++++++++++--------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/smoosh/src/smoosh_channel.erl b/src/smoosh/src/smoosh_channel.erl
index eabb751adbc..3621ec7f765 100644
--- a/src/smoosh/src/smoosh_channel.erl
+++ b/src/smoosh/src/smoosh_channel.erl
@@ -390,27 +390,31 @@ maybe_remonitor_cpid(#state{} = State, DbName, Reason) when is_binary(DbName) ->
     #state{name = Name, active = Active} = State,
     case couch_db:open_int(DbName, []) of
         {ok, Db} ->
-            try couch_db:get_compactor_pid_sync(Db) of
-                nil ->
-                    LogMsg = "~s : exit for compaction of ~p: ~p",
-                    LogArgs = [Name, smoosh_utils:stringify(DbName), Reason],
-                    couch_log:warning(LogMsg, LogArgs),
-                    re_enqueue(DbName),
-                    State;
-                CPid when is_pid(CPid) ->
-                    monitor(process, CPid),
-                    Level = smoosh_utils:log_level("compaction_log_level", "notice"),
-                    LogMsg = "~s: ~s compaction already running. Re-monitor Pid ~p",
-                    LogArgs = [Name, smoosh_utils:stringify(DbName), CPid],
-                    couch_log:Level(LogMsg, LogArgs),
-                    State#state{active = Active#{DbName => CPid}}
+            try
+                case couch_db:get_compactor_pid_sync(Db) of
+                    nil ->
+                        LogMsg = "~s : exit for compaction of ~p: ~p",
+                        LogArgs = [Name, smoosh_utils:stringify(DbName), Reason],
+                        couch_log:warning(LogMsg, LogArgs),
+                        re_enqueue(DbName),
+                        State;
+                    CPid when is_pid(CPid) ->
+                        monitor(process, CPid),
+                        Level = smoosh_utils:log_level("compaction_log_level", "notice"),
+                        LogMsg = "~s: ~s compaction already running. Re-monitor Pid ~p",
+                        LogArgs = [Name, smoosh_utils:stringify(DbName), CPid],
+                        couch_log:Level(LogMsg, LogArgs),
+                        State#state{active = Active#{DbName => CPid}}
+                end
             catch
                 _:Error ->
-                    LogMsg = "~s: error remonitoring db compaction ~p error:~p",
-                    LogArgs = [Name, smoosh_utils:stringify(DbName), Error],
-                    couch_log:warning(LogMsg, LogArgs),
+                    ErrLogMsg = "~s: error remonitoring db compaction ~p error:~p",
+                    ErrLogArgs = [Name, smoosh_utils:stringify(DbName), Error],
+                    couch_log:warning(ErrLogMsg, ErrLogArgs),
                     re_enqueue(DbName),
                     State
+            after
+                couch_db:close(Db)
             end;
         Error = {not_found, no_db_file} ->
             LogMsg = "~s : exit for compaction of ~p: ~p",