fix(fatfs): move readdir-stat cache to per-DIR stream

Move cached_fileinfo and dir_path from vfs_fat_ctx_t to vfs_fat_dir_t so
each open DIR* has its own readdir→stat cache.

components/fatfs/test_apps/flash_wl/main/test_fatfs_flash_wl.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -281,6 +281,34 @@ TEST_CASE("(WL) readdir, stat work as expected", "[fatfs][wear_levelling]")
     test_teardown();
 }
 
+TEST_CASE("(WL) readdir stat cache with two open directories", "[fatfs][wear_levelling]")
+{
+    test_setup();
+    test_fatfs_readdir_stat_dual_opendir("/spiflash/readdir_cache");
+    test_teardown();
+}
+
+TEST_CASE("(WL) readdir stat cache stale after truncate", "[fatfs][wear_levelling]")
+{
+    test_setup();
+    test_fatfs_readdir_stat_stale_after_truncate("/spiflash/readdir_cache");
+    test_teardown();
+}
+
+TEST_CASE("(WL) readdir stat cache stale after unlink", "[fatfs][wear_levelling]")
+{
+    test_setup();
+    test_fatfs_readdir_stat_stale_after_unlink("/spiflash/readdir_cache");
+    test_teardown();
+}
+
+TEST_CASE("(WL) readdir stat cache concurrent dual opendir", "[fatfs][wear_levelling]")
+{
+    test_setup();
+    test_fatfs_readdir_stat_concurrent_dual_opendir("/spiflash/readdir_cache");
+    test_teardown();
+}
+
 TEST_CASE("(WL) opendir, readdir, rewinddir, seekdir work as expected", "[fatfs][wear_levelling]")
 {
     test_setup();

components/fatfs/test_apps/flash_wl/sdkconfig.ci.release

@@ -1,2 +1,3 @@
 CONFIG_COMPILER_OPTIMIZATION_SIZE=y
 CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_SILENT=y
+CONFIG_ESP_MAIN_TASK_STACK_SIZE=4096

components/fatfs/test_apps/flash_wl/sdkconfig.defaults

@@ -13,6 +13,9 @@ CONFIG_ESP_TASK_WDT_INIT=n
 CONFIG_PARTITION_TABLE_CUSTOM=y
 CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"
 
+# LFN is off by default on release/v5.x; required for UTF-8 API encoding
+# and for readdir/stat cache tests that use long path names.
+CONFIG_FATFS_LFN_HEAP=y
 # some tests verify file name encoding
 CONFIG_FATFS_API_ENCODING_UTF_8=y
 CONFIG_FATFS_CODEPAGE_936=y

components/fatfs/test_apps/test_fatfs_common/test_fatfs_common.c

@@ -818,6 +818,251 @@ void test_fatfs_readdir_stat(const char* dir_prefix)
     }
 }
 
+void test_fatfs_readdir_stat_dual_opendir(const char* base_prefix)
+{
+    char dir_a[128];
+    char dir_b[128];
+    char file_a[320];
+    char file_b[320];
+
+    snprintf(dir_a, sizeof(dir_a), "%s/dirA", base_prefix);
+    snprintf(dir_b, sizeof(dir_b), "%s/dirB", base_prefix);
+    snprintf(file_a, sizeof(file_a), "%s/same_name.txt", dir_a);
+    snprintf(file_b, sizeof(file_b), "%s/same_name.txt", dir_b);
+
+    unlink(file_a);
+    unlink(file_b);
+    rmdir(dir_a);
+    rmdir(dir_b);
+    rmdir(base_prefix);
+
+    TEST_ASSERT_EQUAL(0, mkdir(base_prefix, 0755));
+    TEST_ASSERT_EQUAL(0, mkdir(dir_a, 0755));
+    TEST_ASSERT_EQUAL(0, mkdir(dir_b, 0755));
+
+    test_fatfs_create_file_with_text(file_a, "AAAA");
+    test_fatfs_create_file_with_text(file_b, "BBBBBBBB");
+
+    DIR* dir_a_handle = opendir(dir_a);
+    DIR* dir_b_handle = opendir(dir_b);
+    TEST_ASSERT_NOT_NULL(dir_a_handle);
+    TEST_ASSERT_NOT_NULL(dir_b_handle);
+
+    struct dirent* de = NULL;
+    bool found = false;
+    while ((de = readdir(dir_a_handle)) != NULL) {
+        if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) {
+            continue;
+        }
+        TEST_ASSERT_EQUAL_STRING("same_name.txt", de->d_name);
+        found = true;
+        break;
+    }
+    TEST_ASSERT_TRUE(found);
+
+    struct stat st = {0};
+    TEST_ASSERT_EQUAL(0, stat(file_b, &st));
+    TEST_ASSERT_EQUAL(8, st.st_size);
+
+    TEST_ASSERT_EQUAL(0, closedir(dir_a_handle));
+    TEST_ASSERT_EQUAL(0, closedir(dir_b_handle));
+
+    unlink(file_a);
+    unlink(file_b);
+    rmdir(dir_a);
+    rmdir(dir_b);
+    rmdir(base_prefix);
+}
+
+void test_fatfs_readdir_stat_stale_after_truncate(const char* dir_prefix)
+{
+    char filepath[320];
+
+    snprintf(filepath, sizeof(filepath), "%s/stale_truncate.txt", dir_prefix);
+
+    unlink(filepath);
+    rmdir(dir_prefix);
+
+    TEST_ASSERT_EQUAL(0, mkdir(dir_prefix, 0755));
+    test_fatfs_create_file_with_text(filepath, "0123456789");
+
+    DIR* dir = opendir(dir_prefix);
+    TEST_ASSERT_NOT_NULL(dir);
+
+    struct dirent* de = NULL;
+    bool found = false;
+    while ((de = readdir(dir)) != NULL) {
+        if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) {
+            continue;
+        }
+        TEST_ASSERT_EQUAL_STRING("stale_truncate.txt", de->d_name);
+        found = true;
+        break;
+    }
+    TEST_ASSERT_TRUE(found);
+
+    TEST_ASSERT_EQUAL(0, truncate(filepath, 4));
+
+    struct stat st = {0};
+    TEST_ASSERT_EQUAL(0, stat(filepath, &st));
+    TEST_ASSERT_EQUAL(4, st.st_size);
+
+    TEST_ASSERT_EQUAL(0, closedir(dir));
+    unlink(filepath);
+    rmdir(dir_prefix);
+}
+
+void test_fatfs_readdir_stat_stale_after_unlink(const char* dir_prefix)
+{
+    char filepath[320];
+
+    snprintf(filepath, sizeof(filepath), "%s/stale_unlink.txt", dir_prefix);
+
+    unlink(filepath);
+    rmdir(dir_prefix);
+
+    TEST_ASSERT_EQUAL(0, mkdir(dir_prefix, 0755));
+    test_fatfs_create_file_with_text(filepath, "gone");
+
+    DIR* dir = opendir(dir_prefix);
+    TEST_ASSERT_NOT_NULL(dir);
+
+    struct dirent* de = NULL;
+    bool found = false;
+    while ((de = readdir(dir)) != NULL) {
+        if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) {
+            continue;
+        }
+        TEST_ASSERT_EQUAL_STRING("stale_unlink.txt", de->d_name);
+        found = true;
+        break;
+    }
+    TEST_ASSERT_TRUE(found);
+
+    TEST_ASSERT_EQUAL(0, unlink(filepath));
+
+    struct stat st = {0};
+    TEST_ASSERT_EQUAL(-1, stat(filepath, &st));
+    TEST_ASSERT_EQUAL(ENOENT, errno);
+
+    TEST_ASSERT_EQUAL(0, closedir(dir));
+    rmdir(dir_prefix);
+}
+
+typedef struct {
+    const char* dir_path;
+    size_t expected_size;
+    SemaphoreHandle_t done;
+    esp_err_t result;
+} readdir_stat_task_arg_t;
+
+static void readdir_stat_task(void* param)
+{
+    readdir_stat_task_arg_t* arg = (readdir_stat_task_arg_t*) param;
+    char filepath[320];
+    struct stat st = {0};
+    struct dirent* de;
+
+    DIR* dir = opendir(arg->dir_path);
+    if (dir == NULL) {
+        arg->result = ESP_FAIL;
+        xSemaphoreGive(arg->done);
+        vTaskDelete(NULL);
+        return;
+    }
+
+    while ((de = readdir(dir)) != NULL) {
+        if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) {
+            continue;
+        }
+
+        snprintf(filepath, sizeof(filepath), "%s/%s", arg->dir_path, de->d_name);
+        if (stat(filepath, &st) != 0) {
+            arg->result = ESP_FAIL;
+            closedir(dir);
+            xSemaphoreGive(arg->done);
+            vTaskDelete(NULL);
+            return;
+        }
+
+        if ((size_t) st.st_size != arg->expected_size) {
+            arg->result = ESP_FAIL;
+            closedir(dir);
+            xSemaphoreGive(arg->done);
+            vTaskDelete(NULL);
+            return;
+        }
+    }
+
+    closedir(dir);
+    arg->result = ESP_OK;
+    xSemaphoreGive(arg->done);
+    vTaskDelete(NULL);
+}
+
+void test_fatfs_readdir_stat_concurrent_dual_opendir(const char* base_prefix)
+{
+    char dir_a[128];
+    char dir_b[128];
+    char file_a[320];
+    char file_b[320];
+
+    snprintf(dir_a, sizeof(dir_a), "%s/conc_dirA", base_prefix);
+    snprintf(dir_b, sizeof(dir_b), "%s/conc_dirB", base_prefix);
+    snprintf(file_a, sizeof(file_a), "%s/same_name.txt", dir_a);
+    snprintf(file_b, sizeof(file_b), "%s/same_name.txt", dir_b);
+
+    unlink(file_a);
+    unlink(file_b);
+    rmdir(dir_a);
+    rmdir(dir_b);
+    rmdir(base_prefix);
+
+    TEST_ASSERT_EQUAL(0, mkdir(base_prefix, 0755));
+    TEST_ASSERT_EQUAL(0, mkdir(dir_a, 0755));
+    TEST_ASSERT_EQUAL(0, mkdir(dir_b, 0755));
+
+    test_fatfs_create_file_with_text(file_a, "AAAA");
+    test_fatfs_create_file_with_text(file_b, "BBBBBBBB");
+
+    readdir_stat_task_arg_t args_a = {
+        .dir_path = dir_a,
+        .expected_size = 4,
+        .done = xSemaphoreCreateBinary(),
+        .result = ESP_FAIL,
+    };
+    readdir_stat_task_arg_t args_b = {
+        .dir_path = dir_b,
+        .expected_size = 8,
+        .done = xSemaphoreCreateBinary(),
+        .result = ESP_FAIL,
+    };
+    TEST_ASSERT_NOT_NULL(args_a.done);
+    TEST_ASSERT_NOT_NULL(args_b.done);
+
+    const int stack_size = 4096;
+    const int cpuid_0 = 0;
+    const int cpuid_1 = CONFIG_FREERTOS_NUMBER_OF_CORES - 1;
+
+    xTaskCreatePinnedToCore(readdir_stat_task, "readdir_stat_a", stack_size, &args_a, 3, NULL, cpuid_0);
+    xTaskCreatePinnedToCore(readdir_stat_task, "readdir_stat_b", stack_size, &args_b, 3, NULL, cpuid_1);
+
+    xSemaphoreTake(args_a.done, portMAX_DELAY);
+    xSemaphoreTake(args_b.done, portMAX_DELAY);
+
+    TEST_ASSERT_EQUAL(ESP_OK, args_a.result);
+    TEST_ASSERT_EQUAL(ESP_OK, args_b.result);
+
+    vSemaphoreDelete(args_a.done);
+    vSemaphoreDelete(args_b.done);
+
+    unlink(file_a);
+    unlink(file_b);
+    rmdir(dir_a);
+    rmdir(dir_b);
+    rmdir(base_prefix);
+}
+
 void test_fatfs_opendir_readdir_rewinddir(const char* dir_prefix)
 {
     char name_dir_inner_file[64];

components/fatfs/test_apps/test_fatfs_common/test_fatfs_common.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -82,3 +82,11 @@ void test_fatfs_create_contiguous_file(const char* base_path, const char* full_p
 #endif
 
 void test_fatfs_readdir_stat(const char* path);
+
+void test_fatfs_readdir_stat_dual_opendir(const char* base_prefix);
+
+void test_fatfs_readdir_stat_stale_after_truncate(const char* dir_prefix);
+
+void test_fatfs_readdir_stat_stale_after_unlink(const char* dir_prefix);
+
+void test_fatfs_readdir_stat_concurrent_dual_opendir(const char* base_prefix);

components/fatfs/vfs/vfs_fat.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -13,6 +13,9 @@
 #include <sys/fcntl.h>
 #include <sys/lock.h>
 #include "esp_vfs_fat.h"
+#ifdef CONFIG_VFS_SUPPORT_DIR
+#include <sys/queue.h>
+#endif
 #include "esp_vfs.h"
 #include "esp_log.h"
 #include "ff.h"
@@ -20,16 +23,31 @@
 
 #define F_WRITE_MALLOC_ZEROING_BUF_SIZE_LIMIT 512
 
+#if !defined(FILENAME_MAX)
+#define FILENAME_MAX 255
+#endif
+
 #ifdef CONFIG_VFS_SUPPORT_DIR
-struct cached_data{
+struct cached_data {
-#if FF_USE_LFN
+    FILINFO cached_fileinfo;
-	char file_path[FILENAME_MAX+1+FF_LFN_BUF+1]; //FILENAME_MAX+1: for dir_path, FF_LFN_BUF+1: for file name
+    char *cached_file_path;
-#else
+    size_t cached_file_path_size;
-	char file_path[FILENAME_MAX+1+FF_SFN_BUF+1]; //FILENAME_MAX+1: for dir_path, FF_LFN_BUF+1: for file name
-#endif
-	FILINFO fileinfo;
 };
-#endif
+
+typedef struct vfs_fat_dir_t {
+    DIR dir;
+    long offset;
+    FF_DIR ffdir;
+    FILINFO filinfo;
+    struct dirent cur_dirent;
+    const char *dir_path;
+    struct cached_data cached_data;
+    SLIST_ENTRY(vfs_fat_dir_t) open_dirs_entry;
+    char path_buf[]; /* dir_path, then room for one cached entry path */
+} vfs_fat_dir_t;
+
+SLIST_HEAD(vfs_fat_open_dirs, vfs_fat_dir_t);
+#endif // CONFIG_VFS_SUPPORT_DIR
 
 typedef struct {
     char fat_drive[8];  /* FAT drive name */
@@ -41,20 +59,11 @@ typedef struct {
     char tmp_path_buf2[FILENAME_MAX+3]; /* as above; used in functions which take two path arguments */
     uint32_t *flags; /* file descriptor flags, array of max_files size */
 #ifdef CONFIG_VFS_SUPPORT_DIR
-    char dir_path[FILENAME_MAX]; /* variable to store path of opened directory*/
+    struct vfs_fat_open_dirs open_dirs; /* list of open directory streams */
-    struct cached_data cached_fileinfo;
 #endif
     FIL files[0];   /* array with max_files entries; must be the final member of the structure */
 } vfs_fat_ctx_t;
 
-typedef struct {
-    DIR dir;
-    long offset;
-    FF_DIR ffdir;
-    FILINFO filinfo;
-    struct dirent cur_dirent;
-} vfs_fat_dir_t;
-
 /* Date and time storage formats in FAT */
 typedef union {
     struct {
@@ -201,6 +210,9 @@ esp_err_t esp_vfs_fat_register_cfg(const esp_vfs_fat_conf_t* conf, FATFS** out_f
         return ESP_ERR_NO_MEM;
     }
     memset(fat_ctx, 0, ctx_size);
+#ifdef CONFIG_VFS_SUPPORT_DIR
+    SLIST_INIT(&fat_ctx->open_dirs);
+#endif
     fat_ctx->flags = ff_memalloc(max_files * sizeof(*fat_ctx->flags));
     if (fat_ctx->flags == NULL) {
         free(fat_ctx);
@@ -728,6 +740,74 @@ static void update_stat_struct(struct stat *st, FILINFO *info)
     st->st_ctime = 0;
 }
 
+static vfs_fat_dir_t *vfs_fat_dir_alloc(const char *dir_path)
+{
+    const size_t dir_len = strlen(dir_path);
+#if FF_USE_LFN
+    const size_t buf_size = dir_len + 1 + FF_LFN_BUF + 2;
+#else
+    const size_t buf_size = dir_len + 1 + FF_SFN_BUF + 2;
+#endif
+    vfs_fat_dir_t *fat_dir = ff_memalloc(sizeof(vfs_fat_dir_t) + buf_size);
+    if (fat_dir == NULL) {
+        return NULL;
+    }
+    memset(fat_dir, 0, sizeof(*fat_dir));
+    strcpy(fat_dir->path_buf, dir_path);
+    fat_dir->dir_path = fat_dir->path_buf;
+    fat_dir->cached_data.cached_file_path = fat_dir->path_buf + dir_len + 1;
+    fat_dir->cached_data.cached_file_path_size = buf_size - (dir_len + 1);
+    return fat_dir;
+}
+
+static void vfs_fat_clear_dir_stat_cache(vfs_fat_dir_t *fat_dir)
+{
+    memset(&fat_dir->cached_data.cached_fileinfo, 0, sizeof(fat_dir->cached_data.cached_fileinfo));
+    if (fat_dir->cached_data.cached_file_path != NULL) {
+        fat_dir->cached_data.cached_file_path[0] = '\0';
+    }
+}
+
+static void vfs_fat_invalidate_stat_cache(vfs_fat_ctx_t *fat_ctx, const char *path)
+{
+    vfs_fat_dir_t *fat_dir;
+    SLIST_FOREACH(fat_dir, &fat_ctx->open_dirs, open_dirs_entry) {
+        if (fat_dir->cached_data.cached_file_path != NULL &&
+                fat_dir->cached_data.cached_file_path[0] != '\0' &&
+                strcmp(path, fat_dir->cached_data.cached_file_path) == 0) {
+            vfs_fat_clear_dir_stat_cache(fat_dir);
+        }
+    }
+}
+
+static bool vfs_fat_consume_stat_cache(vfs_fat_ctx_t *fat_ctx, const char *path, struct stat *st)
+{
+    vfs_fat_dir_t *fat_dir;
+    SLIST_FOREACH(fat_dir, &fat_ctx->open_dirs, open_dirs_entry) {
+        if (fat_dir->cached_data.cached_file_path != NULL &&
+                fat_dir->cached_data.cached_file_path[0] != '\0' &&
+                strcmp(path, fat_dir->cached_data.cached_file_path) == 0) {
+            update_stat_struct(st, &fat_dir->cached_data.cached_fileinfo);
+            vfs_fat_clear_dir_stat_cache(fat_dir);
+            return true;
+        }
+    }
+    return false;
+}
+
+static void vfs_fat_cache_readdir_entry(vfs_fat_dir_t *fat_dir)
+{
+    vfs_fat_clear_dir_stat_cache(fat_dir);
+    if (strcmp(fat_dir->dir_path, "/") == 0) {
+        snprintf(fat_dir->cached_data.cached_file_path, fat_dir->cached_data.cached_file_path_size,
+                 "/%s", fat_dir->filinfo.fname);
+    } else {
+        snprintf(fat_dir->cached_data.cached_file_path, fat_dir->cached_data.cached_file_path_size,
+                 "%s/%s", fat_dir->dir_path, fat_dir->filinfo.fname);
+    }
+    fat_dir->cached_data.cached_fileinfo = fat_dir->filinfo;
+}
+
 static int vfs_fat_stat(void* ctx, const char * path, struct stat * st)
 {
     if (strcmp(path, "/") == 0) {
@@ -741,16 +821,12 @@ static int vfs_fat_stat(void* ctx, const char * path, struct stat * st)
 
     vfs_fat_ctx_t* fat_ctx = (vfs_fat_ctx_t*) ctx;
 
-    //If fileinfo is already cached by readdir for requested filename,
+    _lock_acquire(&fat_ctx->lock);
-    //then return the same info else obtain fileinfo with f_stat function
+    if (vfs_fat_consume_stat_cache(fat_ctx, path, st)) {
-    if (strcmp(path, fat_ctx->cached_fileinfo.file_path) == 0) {
+        _lock_release(&fat_ctx->lock);
-        update_stat_struct(st, &fat_ctx->cached_fileinfo.fileinfo);
-        memset(&fat_ctx->cached_fileinfo, 0 ,sizeof(FILINFO));
         return 0;
     }
 
-    memset(&fat_ctx->cached_fileinfo, 0 ,sizeof(fat_ctx->cached_fileinfo));
-    _lock_acquire(&fat_ctx->lock);
     prepend_drive_to_path(fat_ctx, &path, NULL);
     FILINFO info;
     FRESULT res = f_stat(path, &info);
@@ -769,6 +845,7 @@ static int vfs_fat_unlink(void* ctx, const char *path)
 {
     vfs_fat_ctx_t* fat_ctx = (vfs_fat_ctx_t*) ctx;
     _lock_acquire(&fat_ctx->lock);
+    vfs_fat_invalidate_stat_cache(fat_ctx, path);
     prepend_drive_to_path(fat_ctx, &path, NULL);
     FRESULT res = f_unlink(path);
     _lock_release(&fat_ctx->lock);
@@ -870,6 +947,8 @@ static int vfs_fat_rename(void* ctx, const char *src, const char *dst)
 {
     vfs_fat_ctx_t* fat_ctx = (vfs_fat_ctx_t*) ctx;
     _lock_acquire(&fat_ctx->lock);
+    vfs_fat_invalidate_stat_cache(fat_ctx, src);
+    vfs_fat_invalidate_stat_cache(fat_ctx, dst);
     prepend_drive_to_path(fat_ctx, &src, &dst);
     FRESULT res = f_rename(src, dst);
     _lock_release(&fat_ctx->lock);
@@ -884,32 +963,41 @@ static int vfs_fat_rename(void* ctx, const char *src, const char *dst)
 static DIR* vfs_fat_opendir(void* ctx, const char* name)
 {
     vfs_fat_ctx_t* fat_ctx = (vfs_fat_ctx_t*) ctx;
-    strlcpy(fat_ctx->dir_path, name, sizeof(fat_ctx->dir_path));
+
     _lock_acquire(&fat_ctx->lock);
-    prepend_drive_to_path(fat_ctx, &name, NULL);
+    vfs_fat_dir_t* fat_dir = vfs_fat_dir_alloc(name);
-    vfs_fat_dir_t* fat_dir = ff_memalloc(sizeof(vfs_fat_dir_t));
     if (!fat_dir) {
         _lock_release(&fat_ctx->lock);
         errno = ENOMEM;
         return NULL;
     }
-    memset(fat_dir, 0, sizeof(*fat_dir));
 
+    prepend_drive_to_path(fat_ctx, &name, NULL);
     FRESULT res = f_opendir(&fat_dir->ffdir, name);
-    _lock_release(&fat_ctx->lock);
     if (res != FR_OK) {
+        _lock_release(&fat_ctx->lock);
         free(fat_dir);
         ESP_LOGD(TAG, "%s: fresult=%d", __func__, res);
         errno = fresult_to_errno(res);
         return NULL;
     }
+
+    SLIST_INSERT_HEAD(&fat_ctx->open_dirs, fat_dir, open_dirs_entry);
+    _lock_release(&fat_ctx->lock);
     return (DIR*) fat_dir;
 }
 
 static int vfs_fat_closedir(void* ctx, DIR* pdir)
 {
     assert(pdir);
+    vfs_fat_ctx_t* fat_ctx = (vfs_fat_ctx_t*) ctx;
     vfs_fat_dir_t* fat_dir = (vfs_fat_dir_t*) pdir;
+
+    _lock_acquire(&fat_ctx->lock);
+    SLIST_REMOVE(&fat_ctx->open_dirs, fat_dir, vfs_fat_dir_t, open_dirs_entry);
+    vfs_fat_clear_dir_stat_cache(fat_dir);
+    _lock_release(&fat_ctx->lock);
+
     FRESULT res = f_closedir(&fat_dir->ffdir);
     free(pdir);
     if (res != FR_OK) {
@@ -932,25 +1020,15 @@ static struct dirent* vfs_fat_readdir(void* ctx, DIR* pdir)
         errno = err;
         return NULL;
     }
-
+    if (out_dirent == NULL) {
-    //Store the FILEINFO in the cached_fileinfo. If the stat function is invoked immediately afterward,
+        return NULL;
-    //the cached_fileinfo will provide the FILEINFO directly, as it was already obtained during the readdir operation.
-    //During directory size calculation, this optimization can reduce the computation time.
-    memset(&fat_ctx->cached_fileinfo, 0 ,sizeof(fat_ctx->cached_fileinfo));
-    if (strcmp(fat_ctx->dir_path, "/") == 0) {
-        snprintf(fat_ctx->cached_fileinfo.file_path, sizeof(fat_ctx->cached_fileinfo.file_path),
-                 "/%s", fat_dir->filinfo.fname);
-    } else {
-        char *temp_file_path = (char*) ff_memalloc(sizeof(fat_ctx->cached_fileinfo.file_path));
-        if (temp_file_path == NULL) {
-            return out_dirent;
-        }
-        snprintf(temp_file_path, sizeof(fat_ctx->cached_fileinfo.file_path),
-                 "%s/%s", fat_ctx->dir_path, fat_dir->filinfo.fname);
-        memcpy(fat_ctx->cached_fileinfo.file_path, temp_file_path, sizeof(fat_ctx->cached_fileinfo.file_path));
-        ff_memfree(temp_file_path);
     }
-    fat_ctx->cached_fileinfo.fileinfo = fat_dir->filinfo;
+
+    /* Cache FILINFO per directory stream so a following stat() on the same path
+     * can reuse data already obtained by readdir (see GH #10220). */
+    _lock_acquire(&fat_ctx->lock);
+    vfs_fat_cache_readdir_entry(fat_dir);
+    _lock_release(&fat_ctx->lock);
     return out_dirent;
 }
 
@@ -1136,6 +1214,7 @@ static int vfs_fat_truncate(void* ctx, const char *path, off_t length)
     }
 
     _lock_acquire(&fat_ctx->lock);
+    vfs_fat_invalidate_stat_cache(fat_ctx, path);
     prepend_drive_to_path(fat_ctx, &path, NULL);
 
     file = (FIL*) ff_memalloc(sizeof(FIL));