修复IWDG超时未配置与dhara resume回滚：看门狗误复位与复位后写入全部丢失，台架全量自检PASS

Drivers/BSP/NET/lftpd/lftpd_io.c

@@ -7,6 +7,8 @@
 
 #include "ff.h"
 #include "private/lftpd_io.h"
+#include "lftpd.h"
+#include "vol_lock.h"
 
 #define DBG_TAG "[LFT_IO]"
 #include "dbg_log.h"
@@ -32,6 +34,24 @@ static const char *to_fatfs_path(const char *path)
 static int s_file_open = 0;
 static FIL s_ftp_file;
 
+/*
+ * 卷锁获取（分片阻塞 + 心跳）：FatFs/FTL 卷状态非线程安全，文件操作序列
+ * 必须与 defaultTask 的 syslog/配置盘写互斥（2026-10-02 台架实证：并发
+ * FTL 写 → dhara journal 竞争 → 长耗时恢复旋转饥饿 defaultTask 主循环
+ * （看门狗喂狗点）→ IWDG 误复位）。等待按 100ms 分片、每片置 FTP 心跳位
+ * （与就绪屏障等待同模式），防长等待造成 FTP 心跳位缺席误复位。
+ * 持有约定：open...close / opendir...closedir 全程持锁；lftpd_io_read/
+ * write 假定锁已由 open 持有；stat/unlink 自行短持。
+ */
+static void lftpd_io_vol_lock_take(void) {
+    for (;;) {
+        if (vol_lock_wait(100u) != 0) {
+            return;
+        }
+        lftpd_task_wd_beat();   /* 看门狗：分片心跳（卷锁等待中） */
+    }
+}
+
 char *lftpd_io_canonicalize_path(const char *base, const char *name)
 {
     if (base == NULL) {
@@ -100,10 +120,12 @@ int lftpd_io_open_read(const char *path)
         DBG_ERROR("open_read '%s': already open", path);
         return -1;
     }
+    lftpd_io_vol_lock_take();
     const char *fpath = to_fatfs_path(path);
     FRESULT fr = f_open(&s_ftp_file, fpath, FA_READ);
     if (fr != FR_OK) {
         DBG_ERROR("open_read '%s': f_open err=%d", fpath, (int)fr);
+        vol_lock_release();
         return -1;
     }
     s_file_open = 1;
@@ -116,10 +138,12 @@ int lftpd_io_open_write(const char *path)
         DBG_ERROR("open_write '%s': already open", path);
         return -1;
     }
+    lftpd_io_vol_lock_take();
     const char *fpath = to_fatfs_path(path);
     FRESULT fr = f_open(&s_ftp_file, fpath, FA_WRITE | FA_CREATE_ALWAYS);
     if (fr != FR_OK) {
         DBG_ERROR("open_write '%s': f_open err=%d", fpath, (int)fr);
+        vol_lock_release();
         return -1;
     }
     s_file_open = 1;
@@ -155,6 +179,7 @@ void lftpd_io_close(int handle)
     if (s_file_open) {
         f_close(&s_ftp_file);
         s_file_open = 0;
+        vol_lock_release();   /* 卷锁：open...close 序列结束 */
     }
 }
 
@@ -163,7 +188,9 @@ int lftpd_io_stat(const char *path, uint32_t *p_size, int *p_is_dir)
     FILINFO fno;
     const char *fpath = to_fatfs_path(path);
 
+    lftpd_io_vol_lock_take();
     if (f_stat(fpath, &fno) != FR_OK) {
+        vol_lock_release();
         return -1;
     }
 
@@ -174,15 +201,19 @@ int lftpd_io_stat(const char *path, uint32_t *p_size, int *p_is_dir)
         *p_is_dir = (fno.fattrib & AM_DIR) ? 1 : 0;
     }
 
+    vol_lock_release();
     return 0;
 }
 
 int lftpd_io_unlink(const char *path)
 {
     const char *fpath = to_fatfs_path(path);
+    lftpd_io_vol_lock_take();
     if (f_unlink(fpath) == FR_OK) {
+        vol_lock_release();
         return 0;
     }
+    vol_lock_release();
     return -1;
 }
 
@@ -193,11 +224,13 @@ void *lftpd_io_opendir(const char *path)
         return NULL;
     }
     const char *fpath = to_fatfs_path(path);
+    lftpd_io_vol_lock_take();
     if (f_opendir(dp, fpath) != FR_OK) {
         vPortFree(dp);
+        vol_lock_release();
         return NULL;
     }
-    return (void *)dp;
+    return (void *)dp;   /* 卷锁持有至 lftpd_io_closedir */
 }
 
 int lftpd_io_readdir(void *dp, char *name, int name_max, uint32_t *p_size, int *p_is_dir)
@@ -233,5 +266,6 @@ void lftpd_io_closedir(void *dp)
     if (dp != NULL) {
         f_closedir((DIR *)dp);
         vPortFree(dp);
+        vol_lock_release();   /* 卷锁：opendir...closedir 序列结束 */
     }
 }