[fix]fix tmpfs bug (#8970)

* first

* second

* thrid

* Update SConscript

* tmpfs testcase default n

* Update dfs_tmpfs.c

* format document

---------

Co-authored-by: zhujiale <zhujiale@rt-thread.com>

components/dfs/dfs_v2/filesystems/tmpfs/dfs_tmpfs.c

@@ -294,18 +294,17 @@ find_subpath:
 
 static ssize_t dfs_tmpfs_read(struct dfs_file *file, void *buf, size_t count, off_t *pos)
 {
-    rt_size_t length;
+    ssize_t length;
     struct tmpfs_file *d_file;
-
     d_file = (struct tmpfs_file *)file->vnode->data;
     RT_ASSERT(d_file != NULL);
 
     rt_mutex_take(&file->vnode->lock, RT_WAITING_FOREVER);
-
+    ssize_t size = (ssize_t)file->vnode->size;
-    if (count < file->vnode->size - *pos)
+    if ((ssize_t)count < size - *pos)
         length = count;
     else
-        length = file->vnode->size - *pos;
+        length = size - *pos;
 
     if (length > 0)
         memcpy(buf, &(d_file->data[*pos]), length);

examples/utest/testcases/Kconfig

@@ -14,7 +14,7 @@ source "$RTT_DIR/examples/utest/testcases/drivers/serial_v2/Kconfig"
 source "$RTT_DIR/examples/utest/testcases/drivers/ipc/Kconfig"
 source "$RTT_DIR/examples/utest/testcases/posix/Kconfig"
 source "$RTT_DIR/examples/utest/testcases/mm/Kconfig"
-
+source "$RTT_DIR/examples/utest/testcases/tmpfs/Kconfig"
 endif
 
 endmenu

examples/utest/testcases/tmpfs/Kconfig

@@ -0,0 +1,6 @@
+menu "Tmpfs Testcase"
+
+config UTEST_TMPFS_CP
+    bool "tmpfs cp test"
+    default n
+endmenu

examples/utest/testcases/tmpfs/SConscript

@@ -0,0 +1,13 @@
+Import('rtconfig')
+from building import *
+
+cwd     = GetCurrentDir()
+src     = []
+CPPPATH = [cwd]
+
+if GetDepend(['RT_USING_SMART','UTEST_TMPFS_CP']):
+    src += ['tmpfs.c']
+
+group = DefineGroup('utestcases', src, depend = ['RT_USING_UTESTCASES'], CPPPATH = CPPPATH)
+
+Return('group')

examples/utest/testcases/tmpfs/tmpfs.c

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2006-2019, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2024-5-20     Zhujiale   the first version
+ */
+#include <rtthread.h>
+#include <stdlib.h>
+#include <msh.h>
+#include "utest.h"
+#include "utest_assert.h"
+#include "common.h"
+
+void run_copy()
+{
+    int ret = 0;
+    ret     = msh_exec("cd /tmp", 7);
+    if (ret != 0)
+    {
+        LOG_E("errno=%d, ret=%d\n", errno, ret);
+        LOG_E("cd /tmp error");
+        uassert_false(1);
+    }
+    uassert_true(1);
+    ret = msh_exec("touch test", 10);
+    if (ret != 0)
+    {
+        LOG_E("errno=%d, ret=%d\n", errno, ret);
+        LOG_E("touch test error");
+        uassert_false(1);
+    }
+    uassert_true(1);
+    ret = msh_exec("echo this_is_a_test_file test", 29);
+    if (ret != 0)
+    {
+        LOG_E("errno=%d, ret=%d\n", errno, ret);
+        LOG_E("echo this_is_a_test_file test error");
+        uassert_false(1);
+    }
+    uassert_true(1);
+    ret = msh_exec("cp test test1", 13);
+    if (ret != 0)
+    {
+        LOG_E("errno=%d, ret=%d\n", errno, ret);
+        LOG_E("cp test test1 error");
+        uassert_false(1);
+    }
+
+    uassert_true(1);
+}
+
+static rt_err_t utest_tc_init(void)
+{
+    return RT_EOK;
+}
+
+static rt_err_t utest_tc_cleanup(void)
+{
+    return RT_EOK;
+}
+static void testcase(void)
+{
+    UTEST_UNIT_RUN(run_copy);
+}
+UTEST_TC_EXPORT(testcase, "testcase.tfs.tmpfs", utest_tc_init, utest_tc_cleanup, 10);