Fixed potential file system corruption when truncating or overwriting file data with fault tolerant mode enabled (#78)

* _fx_fault_tolerant_cleanup_FAT_chain(): Add checks to prevent starting a new cluster deletion session in some corner cases where the end of the chain is reached.

* Fixed formatting of previous commit.

common/inc/fx_api.h

@@ -138,9 +138,9 @@ extern   "C" {
 #define AZURE_RTOS_FILEX
 #define FILEX_MAJOR_VERSION     6
 #define FILEX_MINOR_VERSION     4
-#define FILEX_PATCH_VERSION     2
+#define FILEX_PATCH_VERSION     5
-#define FILEX_BUILD_VERSION     202503
+#define FILEX_BUILD_VERSION     202504
-#define FILEX_HOTFIX_VERSION    ''
+#define FILEX_HOTFIX_VERSION    ' '
 
 /* Define the following symbols for backward compatibility */
 #define EL_PRODUCT_FILEX

common/src/fx_fault_tolerant_cleanup_FAT_chain.c

@@ -207,7 +207,7 @@ ULONG                        last_FAT_sector;
 
     /* At this point, the head_cluster points to the cluster chain that is to be removed. */
 
-    /* Tail cluster points to the back of the origianal FAT chain where the new chain is attached to.
+    /* Tail cluster points to the back of the original FAT chain where the new chain is attached to.
        The remove process terminates once this cluster is encountered. */
     tail_cluster = _fx_utility_32_unsigned_read((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_insertion_back);
 
@@ -262,7 +262,11 @@ ULONG                        last_FAT_sector;
             {
                 if (head_cluster == next_session || next_session == FX_FREE_CLUSTER)
                 {
-                    next_session = next_cluster;
+                    /* Do not start another session if this is the end of the chain.  */
+                    if (next_cluster != tail_cluster)
+                    {
+                        next_session = next_cluster;
+                    }
                 }
                 break;
             }
@@ -277,7 +281,11 @@ ULONG                        last_FAT_sector;
         /* Get next session. */
         if (cache_count == cache_max)
         {
-            next_session = next_cluster;
+            /* Do not start another session if this is the end of the chain.  */
+            if (next_cluster != tail_cluster)
+            {
+                next_session = next_cluster;
+            }
         }
 
         /* Update head cluster and next session into log file. */

common/src/fx_media_format.c

@@ -161,9 +161,11 @@ UINT   sectors_per_fat, f, s;
     media_ptr -> fx_media_hidden_sectors =              hidden_sectors;
 
     /* Initialize the supplied media I/O driver.  First, build the
-       initialize driver request.  */
+       initialize driver request. Set the fx_media_driver_status to FX_MEDIA_INVALID
+       to let the driver know that the request is issued from a fx_media_format() call
+     */
     media_ptr -> fx_media_driver_request =              FX_DRIVER_INIT;
-    media_ptr -> fx_media_driver_status =               FX_IO_ERROR;
+    media_ptr -> fx_media_driver_status =               FX_MEDIA_INVALID;
     media_ptr -> fx_media_driver_info =                 driver_info_ptr;
     media_ptr -> fx_media_driver_write_protect =        FX_FALSE;
     media_ptr -> fx_media_driver_free_sector_update =   FX_FALSE;

common/src/fx_media_open.c

@@ -261,9 +261,11 @@ FX_INT_SAVE_AREA
     FX_TRACE_IN_LINE_INSERT(FX_TRACE_MEDIA_OPEN, media_ptr, media_driver, memory_ptr, memory_size, FX_TRACE_MEDIA_EVENTS, 0, 0)
 
     /* Initialize the supplied media I/O driver.  First, build the
-       initialize driver request.  */
+       initialize driver request. Set the fx_media_driver_status to FX_MEDIA_NOT_OPEN
+       to let the driver understand that the request is issued from a fx_media_open() call.
+    */
     media_ptr -> fx_media_driver_request =              FX_DRIVER_INIT;
-    media_ptr -> fx_media_driver_status =               FX_IO_ERROR;
+    media_ptr -> fx_media_driver_status =               FX_MEDIA_NOT_OPEN;
     media_ptr -> fx_media_driver_info =                 driver_info_ptr;
     media_ptr -> fx_media_driver_write_protect =        FX_FALSE;
     media_ptr -> fx_media_driver_free_sector_update =   FX_FALSE;

ports/rxv1/gnu/CMakeLists.txt

@@ -0,0 +1,9 @@
+target_sources(${PROJECT_NAME} PRIVATE
+    # {{BEGIN_TARGET_SOURCES}}
+
+    # {{END_TARGET_SOURCES}}
+)
+
+target_include_directories(${PROJECT_NAME} PUBLIC
+    ${CMAKE_CURRENT_LIST_DIR}/inc
+)

ports/rxv1/gnu/inc/fx_port.h

@@ -0,0 +1,24 @@
+/***************************************************************************
+ * Copyright (c) 2024 Microsoft Corporation 
+ * 
+ * This program and the accompanying materials are made available under the
+ * terms of the MIT License which is available at
+ * https://opensource.org/licenses/MIT.
+ * 
+ * SPDX-License-Identifier: MIT
+ **************************************************************************/
+
+
+/**************************************************************************/
+/**************************************************************************/
+/**                                                                       */ 
+/** FileX Component                                                       */
+/**                                                                       */
+/**   Port Specific                                                       */
+/**                                                                       */
+/**************************************************************************/
+/**************************************************************************/
+
+/* Include the generic version of fx_port.h. */
+#include "../../../generic/inc/fx_port.h"
+

ports/rxv2/gnu/CMakeLists.txt

@@ -0,0 +1,9 @@
+target_sources(${PROJECT_NAME} PRIVATE
+    # {{BEGIN_TARGET_SOURCES}}
+
+    # {{END_TARGET_SOURCES}}
+)
+
+target_include_directories(${PROJECT_NAME} PUBLIC
+    ${CMAKE_CURRENT_LIST_DIR}/inc
+)

ports/rxv2/gnu/inc/fx_port.h

@@ -0,0 +1,24 @@
+/***************************************************************************
+ * Copyright (c) 2024 Microsoft Corporation 
+ * 
+ * This program and the accompanying materials are made available under the
+ * terms of the MIT License which is available at
+ * https://opensource.org/licenses/MIT.
+ * 
+ * SPDX-License-Identifier: MIT
+ **************************************************************************/
+
+
+/**************************************************************************/
+/**************************************************************************/
+/**                                                                       */ 
+/** FileX Component                                                       */
+/**                                                                       */
+/**   Port Specific                                                       */
+/**                                                                       */
+/**************************************************************************/
+/**************************************************************************/
+
+/* Include the generic version of fx_port.h. */
+#include "../../../generic/inc/fx_port.h"
+

ports/rxv3/gnu/CMakeLists.txt

@@ -0,0 +1,9 @@
+target_sources(${PROJECT_NAME} PRIVATE
+    # {{BEGIN_TARGET_SOURCES}}
+
+    # {{END_TARGET_SOURCES}}
+)
+
+target_include_directories(${PROJECT_NAME} PUBLIC
+    ${CMAKE_CURRENT_LIST_DIR}/inc
+)

ports/rxv3/gnu/inc/fx_port.h

@@ -0,0 +1,24 @@
+/***************************************************************************
+ * Copyright (c) 2024 Microsoft Corporation 
+ * 
+ * This program and the accompanying materials are made available under the
+ * terms of the MIT License which is available at
+ * https://opensource.org/licenses/MIT.
+ * 
+ * SPDX-License-Identifier: MIT
+ **************************************************************************/
+
+
+/**************************************************************************/
+/**************************************************************************/
+/**                                                                       */ 
+/** FileX Component                                                       */
+/**                                                                       */
+/**   Port Specific                                                       */
+/**                                                                       */
+/**************************************************************************/
+/**************************************************************************/
+
+/* Include the generic version of fx_port.h. */
+#include "../../../generic/inc/fx_port.h"
+