commit 57dfbfb7ece2157afddf53dab2f14513093d233b
author Nico Huber <nico.h@gmx.de> Wed Dec 13 23:24:16 2023 +0100
committer Nico Huber <nico.h@gmx.de> Thu Dec 14 00:08:59 2023 +0100
tree 4d0363cbb657d3cc32df0c3a0427aa5a6bcd0cde
parent f83364ad3b537417f3870fd464844537d426b567

ext2: Distinguish physical (always valid) and logical (per file) cached blocks

src/filo-fs-ext2.adb

diff --git a/src/filo-fs-ext2.adb b/src/filo-fs-ext2.adb
index 32a16c3..1a151b9 100644
--- a/src/filo-fs-ext2.adb
+++ b/src/filo-fs-ext2.adb
@@ -155,7 +155,8 @@
      (State       : in out T;
       Phys        : in     FSBlock_Offset;
       Level       : in     Block_Cache_Index;
-      Logical_Off : in     FSBlock_Logical;
+      Label       : in     Cache_Label;
+      Logical     : in     Boolean := True;
       Cache_Start :    out Max_Block_Index;
       Cache_End   :    out Max_Block_Index;
       Success     :    out Boolean)
@@ -171,7 +172,9 @@
    begin
       Cache_Start := Cache_Level * Block_Size;
       Cache_End   := Cache_Start + Block_Size - 1;
-      if State.Block_Cache_Index (Cache_Level) = Logical_Off then
+      if State.Block_Cache_Logical (Cache_Level) = Logical and
+         State.Block_Cache_Label (Cache_Level) = Label
+      then
          Success := True;
       else
          Read_FSBlock
@@ -179,10 +182,36 @@
             Buf      => State.Block_Cache (Cache_Start .. Cache_End),
             FSBlock  => Phys,
             Success  => Success);
-         State.Block_Cache_Index (Cache_Level) := Logical_Off;
+         State.Block_Cache_Logical (Cache_Level) := Logical;
+         State.Block_Cache_Label (Cache_Level) := Label;
       end if;
    end Cache_FSBlock;
 
+   procedure Cache_FSBlock
+     (State       : in out T;
+      Phys        : in     FSBlock_Offset;
+      Level       : in     Block_Cache_Index;
+      Cache_Start :    out Max_Block_Index;
+      Cache_End   :    out Max_Block_Index;
+      Success     :    out Boolean)
+   with
+      Post => Cache_End = Cache_Start + 2 ** State.Block_Size_Bits
+   is
+   begin
+      Cache_FSBlock (State, Phys, Level, Cache_Label (Phys),
+                     False, Cache_Start, Cache_End, Success);
+   end Cache_FSBlock;
+
+   procedure Reset_Cache_Logical (State : in out T) is
+   begin
+      for I in Block_Cache_Index loop
+         if State.Block_Cache_Logical (I) then
+            State.Block_Cache_Logical (I) := False;
+            State.Block_Cache_Label (I) := 0;
+         end if;
+      end loop;
+   end Reset_Cache_Logical;
+
    procedure Ext2_Block_Map
      (State       : in out T;
       Logical     : in     FSBlock_Logical;
@@ -223,7 +252,7 @@
            (State       => State,
             Phys        => Indirect_Block_Phys,
             Level       => Level,
-            Logical_Off => Logical_Off,
+            Label       => Cache_Label (Logical_Off),
             Cache_Start => Cache_Start,
             Cache_End   => Cache_End,
             Success     => Success);
@@ -448,7 +477,7 @@
            (State       => State,
             Phys        => Current,
             Level       => Depth,
-            Logical_Off => Logical_Off,
+            Label       => Cache_Label (Logical_Off),
             Cache_Start => Cache_Start,
             Cache_End   => Cache_End,
             Success     => Success);