From de44109ba01bb5fc280c043c713c9df95f889fa9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= <loic.hoguin@broadcom.com>
Date: Wed, 2 Jul 2025 10:08:40 +0200
Subject: [PATCH] CQ: Retry opening write file when writing messages

Followup to ff8ecf1cf7cfd22981668cbed374a5572560dd80
only this time it's for the index.

(cherry picked from commit af8c0af4086ac9e02852d0b3d06cf5dcdb8b999f)
---
 .../src/rabbit_classic_queue_index_v2.erl     |  4 ++-
 .../src/rabbit_classic_queue_store_v2.erl     | 23 ++-----------
 deps/rabbit/src/rabbit_file.erl               | 32 +++++++++++++++++++
 3 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/deps/rabbit/src/rabbit_classic_queue_index_v2.erl b/deps/rabbit/src/rabbit_classic_queue_index_v2.erl
index 3dc4d2f9bcc1..c0c812abf99c 100644
--- a/deps/rabbit/src/rabbit_classic_queue_index_v2.erl
+++ b/deps/rabbit/src/rabbit_classic_queue_index_v2.erl
@@ -591,7 +591,9 @@ publish(MsgId, SeqId, Location, Props, IsPersistent, ShouldConfirm, TargetRamCou
 new_segment_file(Segment, SegmentEntryCount, State = #qi{ segments = Segments }) ->
     #qi{ fds = OpenFds } = reduce_fd_usage(Segment, State),
     false = maps:is_key(Segment, OpenFds), %% assert
-    {ok, Fd} = file:open(segment_file(Segment, State), [read, write, raw, binary]),
+    {ok, Fd} = rabbit_file:open_eventually(
+        segment_file(Segment, State),
+        [read, write, raw, binary]),
     %% We then write the segment file header. It contains
     %% some useful info and some reserved bytes for future use.
     %% We currently do not make use of this information. It is
diff --git a/deps/rabbit/src/rabbit_classic_queue_store_v2.erl b/deps/rabbit/src/rabbit_classic_queue_store_v2.erl
index 8e8d0de92d8e..d3286da45532 100644
--- a/deps/rabbit/src/rabbit_classic_queue_store_v2.erl
+++ b/deps/rabbit/src/rabbit_classic_queue_store_v2.erl
@@ -194,25 +194,6 @@ maybe_flush_buffer(State = #qs{ write_buffer_size = WriteBufferSize }) ->
         false -> State
     end.
 
-open_eventually(File, Modes) ->
-    open_eventually(File, Modes, 3).
-
-open_eventually(_, _, 0) ->
-    {error, eacces};
-open_eventually(File, Modes, N) ->
-    case file:open(File, Modes) of
-        OK = {ok, _} ->
-            OK;
-        %% When the current write file was recently deleted it
-        %% is possible on Windows to get an {error,eacces}.
-        %% Sometimes Windows sets the files to "DELETE PENDING"
-        %% state and delays deletion a bit. So we wait 10ms and
-        %% try again up to 3 times.
-        {error, eacces} ->
-            timer:sleep(10),
-            open_eventually(File, Modes, N - 1)
-    end.
-
 flush_buffer(State = #qs{ write_buffer_size = 0 }, _) ->
     State;
 flush_buffer(State0 = #qs{ write_buffer = WriteBuffer }, FsyncFun) ->
@@ -223,7 +204,9 @@ flush_buffer(State0 = #qs{ write_buffer = WriteBuffer }, FsyncFun) ->
     Writes = flush_buffer_build(WriteList, CheckCRC32, SegmentEntryCount),
     %% Then we do the writes for each segment.
     State = lists:foldl(fun({Segment, LocBytes}, FoldState) ->
-        {ok, Fd} = open_eventually(segment_file(Segment, FoldState), [read, write, raw, binary]),
+        {ok, Fd} = rabbit_file:open_eventually(
+            segment_file(Segment, FoldState),
+            [read, write, raw, binary]),
         case file:position(Fd, eof) of
             {ok, 0} ->
                 %% We write the file header if it does not exist.
diff --git a/deps/rabbit/src/rabbit_file.erl b/deps/rabbit/src/rabbit_file.erl
index 8fbd663bbe7b..a054e8748763 100644
--- a/deps/rabbit/src/rabbit_file.erl
+++ b/deps/rabbit/src/rabbit_file.erl
@@ -17,6 +17,7 @@
 -export([read_file_info/1]).
 -export([filename_as_a_directory/1]).
 -export([filename_to_binary/1, binary_to_filename/1]).
+-export([open_eventually/2]).
 
 -define(TMP_EXT, ".tmp").
 
@@ -338,3 +339,34 @@ binary_to_filename(Bin) when is_binary(Bin) ->
         Other ->
             erlang:error(Other)
     end.
+
+%% On Windows the file may be in "DELETE PENDING" state following
+%% its deletion (when the last message was acked). A subsequent
+%% open may fail with an {error,eacces}. In that case we wait 10ms
+%% and retry up to 3 times.
+
+-spec open_eventually(File, Modes) -> {ok, IoDevice} | {error, Reason} when
+      File :: Filename | iodata(),
+      Filename :: file:name_all(),
+      Modes :: [file:mode() | ram | directory],
+      IoDevice :: file:io_device(),
+      Reason :: file:posix() | badarg | system_limit.
+
+open_eventually(File, Modes) ->
+    open_eventually(File, Modes, 3).
+
+open_eventually(_, _, 0) ->
+    {error, eacces};
+open_eventually(File, Modes, N) ->
+    case file:open(File, Modes) of
+        OK = {ok, _} ->
+            OK;
+        %% When the current write file was recently deleted it
+        %% is possible on Windows to get an {error,eacces}.
+        %% Sometimes Windows sets the files to "DELETE PENDING"
+        %% state and delays deletion a bit. So we wait 10ms and
+        %% try again up to 3 times.
+        {error, eacces} ->
+            timer:sleep(10),
+            open_eventually(File, Modes, N - 1)
+    end.