Posix: Add Support for posix fstat

lib/posix/options/Kconfig.fs

@@ -12,8 +12,15 @@ menuconfig POSIX_FILE_SYSTEM
 
 if POSIX_FILE_SYSTEM
 
+config POSIX_FILE_SYSTEM_FSTAT
+	bool "POSIX fstat() API support"
+	default n
+	help
+	  Select 'y' here to provide POSIX fstat() functionality.
+
 config POSIX_FILE_SYSTEM_ALIAS_FSTAT
 	bool
+	depends on POSIX_FILE_SYSTEM_FSTAT
 	help
 	  Select 'y' here and Zephyr will provide an alias for fstat() as _fstat().
 

lib/posix/options/fs.c

@@ -11,6 +11,7 @@
 #include <limits.h>
 #include <zephyr/posix/unistd.h>
 #include <zephyr/posix/dirent.h>
+#include <stdio.h>
 #include <string.h>
 #include <zephyr/sys/fdtable.h>
 #include <zephyr/posix/sys/stat.h>
@@ -28,6 +29,9 @@ struct posix_fs_desc {
 	};
 	bool is_dir;
 	bool used;
+#if defined(CONFIG_POSIX_FILE_SYSTEM_FSTAT)
+	char path[MAX_FILE_NAME];
+#endif
 };
 
 static struct posix_fs_desc desc_array[CONFIG_POSIX_OPEN_MAX];
@@ -120,6 +124,11 @@ int zvfs_open(const char *name, int flags)
 
 	zvfs_finalize_fd(fd, ptr, &fs_fd_op_vtable);
 
+#if defined(CONFIG_POSIX_FILE_SYSTEM_FSTAT)
+	memset(ptr->path, 0, MAX_FILE_NAME);
+	snprintf(ptr->path, MAX_FILE_NAME, "%s", name);
+#endif
+
 	return fd;
 }
 
@@ -157,6 +166,15 @@ static int fs_ioctl_vmeth(void *obj, unsigned int request, va_list args)
 		}
 		break;
 	}
+#if defined(CONFIG_POSIX_FILE_SYSTEM_FSTAT)
+	case ZFD_IOCTL_STAT: {
+		struct stat *buf = NULL;
+
+		buf = va_arg(args, struct stat *);
+		rc = stat(ptr->path, buf);
+		break;
+	}
+#endif
 	case ZFD_IOCTL_TRUNCATE: {
 		off_t length;
 
@@ -460,6 +478,11 @@ int mkdir(const char *path, mode_t mode)
 
 int fstat(int fildes, struct stat *buf)
 {
+	if (!IS_ENABLED(CONFIG_POSIX_FILE_SYSTEM_FSTAT)) {
+		errno = ENOTSUP;
+		return -1;
+	}
+
 	return zvfs_fstat(fildes, buf);
 }
 #ifdef CONFIG_POSIX_FILE_SYSTEM_ALIAS_FSTAT

tests/posix/fs/prj.conf

@@ -6,3 +6,7 @@ CONFIG_POSIX_FILE_SYSTEM=y
 CONFIG_ZTEST=y
 CONFIG_MAIN_STACK_SIZE=4096
 CONFIG_EVENTFD=n
+CONFIG_FS_FATFS_LFN=y
+CONFIG_FS_FATFS_MAX_LFN=32
+CONFIG_FILE_SYSTEM_MAX_FILE_NAME=32
+CONFIG_POSIX_FILE_SYSTEM_FSTAT=y

tests/posix/fs/src/test_fs_fstat.c

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2024 Linumiz
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <errno.h>
+#include <zephyr/posix/fcntl.h>
+#include <zephyr/posix/unistd.h>
+#include <zephyr/posix/sys/stat.h>
+#include "test_fs.h"
+
+#define FILL_SIZE      128
+#define TEST_FILE_SIZE 80
+#define APPEND_DATA    "hello_world"
+
+static void create_file(const char *filename, uint32_t size)
+{
+	int fh;
+
+	fh = open(filename, O_CREAT | O_WRONLY);
+	zassert(fh >= 0, "Failed creating test file");
+
+	uint8_t filling[FILL_SIZE];
+
+	while (size > FILL_SIZE) {
+		zassert_equal(FILL_SIZE, write(fh, filling, FILL_SIZE));
+		size -= FILL_SIZE;
+	}
+
+	zassert_equal(size, write(fh, filling, size));
+
+	zassert_ok(close(fh));
+}
+
+static void before_fn(void *unused)
+{
+	ARG_UNUSED(unused);
+
+	create_file(TEST_FILE, TEST_FILE_SIZE);
+}
+
+static void after_fn(void *unused)
+{
+	ARG_UNUSED(unused);
+
+	zassert_ok(unlink(TEST_FILE));
+}
+ZTEST_SUITE(posix_fs_fstat_test, NULL, test_mount, before_fn, after_fn, test_unmount);
+
+/**
+ * @brief Test fstat command on file
+ *
+ */
+ZTEST(posix_fs_fstat_test, test_fs_fstat_file)
+{
+	int fd = -1;
+	struct stat buf = {0};
+
+	fd = open(TEST_FILE, O_APPEND | O_WRONLY);
+	zassert(fd >= 0, "Failed creating test file");
+
+	zassert_equal(0, fstat(fd, &buf));
+	zassert_equal(TEST_FILE_SIZE, buf.st_size);
+	zassert_equal(S_IFREG, buf.st_mode);
+	zassert_not_equal(-1, write(fd, APPEND_DATA, strlen(APPEND_DATA)));
+
+	/* In Zephyr fs_stat, File info are updated only after close */
+	zassert_ok(close(fd));
+	fd = open(TEST_FILE, O_RDWR);
+	zassert(fd >= 0, "Failed creating test file");
+
+	zassert_equal(0, fstat(fd, &buf));
+	zassert_equal(TEST_FILE_SIZE + strlen(APPEND_DATA), buf.st_size);
+	zassert_equal(S_IFREG, buf.st_mode);
+
+	zassert_equal(-1, fstat(-1, &buf));
+	zassert_equal(EBADF, errno);
+
+	zassert_ok(close(fd));
+}