fs: Add a sample app to demo Zephyr file system API

Demonstrates the Zephyr file system APIs. This currently
runs on FAT FS using RAM emulation of disk.

Origin: Original
Jira: ZEP-285 ZEP-228 ZEP-481 ZEP-446
Change-Id: If459b8c2f819a2a38c8c4d805ec3f689dfcdef17
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>

samples/fs/fat_fs/Makefile

@@ -0,0 +1,5 @@
+KERNEL_TYPE = nano
+BOARD ?= qemu_x86
+CONF_FILE = prj.conf
+
+include ${ZEPHYR_BASE}/Makefile.inc

samples/fs/fat_fs/README.txt

@@ -0,0 +1,93 @@
+Title: Zephyr File System Demo
+
+Description:
+
+Demonstrates basic file and dir operations using the Zephyr file system.
+--------------------------------------------------------------------------------
+
+Building and Running Project:
+
+While this demo uses RAM to emulate storage, it can be tested using QEMU.
+
+Following command will build it for running on QEMU:
+
+    make qemu
+
+--------------------------------------------------------------------------------
+
+Troubleshooting:
+
+Problems caused by out-dated project information can be addressed by
+issuing one of the following commands then rebuilding the project:
+
+    make clean          # discard results of previous builds
+                        # but keep existing configuration info
+or
+    make pristine       # discard results of previous builds
+                        # and restore pre-defined configuration info
+
+--------------------------------------------------------------------------------
+
+Sample Output:
+
+File System Demo!
+
+Creating new file testfile.txt
+Opened file testfile.txt
+Data successfully written!
+Data written:"hello world!"
+
+Data successfully read!
+Data read:"hello world!"
+
+Closed file testfile.txt
+File (testfile.txt) deleted successfully!
+Created dir sub1!
+Created dir sub2!
+Created dir sub1/sub3!
+Creating new file testfile.txt
+Opened file testfile.txt
+Creating new file sub1/testfile.txt
+Opened file sub1/testfile.txt
+Creating new file sub2/testfile.txt
+Opened file sub2/testfile.txt
+Creating new file sub1/sub3/file1.txt
+Opened file sub1/sub3/file1.txt
+Creating new file sub1/sub3/file2.txt
+Opened file sub1/sub3/file2.txt
+Data successfully written!
+Data written:"1"
+
+Data successfully written!
+Data written:"12"
+
+Data successfully written!
+Data written:"123"
+
+Data successfully written!
+Data written:"1234"
+
+Data successfully written!
+Data written:"12345"
+
+Closed file testfile.txt
+Closed file sub1/testfile.txt
+Closed file sub2/testfile.txt
+Closed file sub1/sub3/file1.txt
+Closed file sub1/sub3/file2.txt
+
+Listing dir /:
+[DIR ] SUB1
+[DIR ] SUB2
+[FILE] TESTFILE.TXT (size = 1)
+
+Listing dir sub1:
+[DIR ] SUB3
+[FILE] TESTFILE.TXT (size = 2)
+
+Listing dir sub2:
+[FILE] TESTFILE.TXT (size = 3)
+
+Listing dir sub1/sub3:
+[FILE] FILE1.TXT (size = 4)
+[FILE] FILE2.TXT (size = 5)

samples/fs/fat_fs/prj.conf

@@ -0,0 +1,3 @@
+CONFIG_FILE_SYSTEM=y
+CONFIG_FILE_SYSTEM_FAT=y
+CONFIG_FS_FAT_RAM_DISK=y

samples/fs/fat_fs/src/Makefile

@@ -0,0 +1 @@
+obj-y += main.o

samples/fs/fat_fs/src/main.c

@@ -0,0 +1,379 @@
+/*
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <zephyr.h>
+#include <stdio.h>
+#include <string.h>
+#include <misc/printk.h>
+#include <fs.h>
+
+static void file_tests(void);
+static void dir_tests(void);
+
+#define TEST_SUB_DIR "sub1"
+#define TEST_FILE "testfile.txt"
+
+/*
+ * @file
+ * @brief File system demo
+ * Demonstrates the ZEPHYR File System APIs
+ */
+
+void main(void)
+{
+	printk("File System Demo!\n\n");
+
+	file_tests();
+	dir_tests();
+}
+
+static int check_file_dir_exists(const char *path)
+{
+	int res;
+	struct zfs_dirent entry;
+
+	res = fs_stat(path, &entry);
+
+	return !res;
+}
+
+static int open_file(ZFILE *fp, const char *path)
+{
+	int res;
+
+	if (check_file_dir_exists(path)) {
+		printk("Opening existing file %s\n", path);
+	} else {
+		printk("Creating new file %s\n", path);
+	}
+
+	res = fs_open(fp, path);
+	if (res) {
+		printk("Failed opening file [%d]\n", res);
+		return res;
+	}
+
+	printk("Opened file %s\n", path);
+
+	return res;
+}
+
+static const char test_str[] = "hello world!";
+
+static int write_test(ZFILE *fp, off_t ofs, const char *str)
+{
+	ssize_t brw;
+	int res;
+
+	res = fs_seek(fp, ofs, SEEK_SET);
+	if (res) {
+		printk("fs_seek failed [%d]\n", res);
+		fs_close(fp);
+		return res;
+	}
+
+	brw = fs_write(fp, (char *)str, strlen(str));
+	if (brw < 0) {
+		printk("Failed writing to file [%d]\n", brw);
+		fs_close(fp);
+		return brw;
+	}
+	if (brw < strlen(str)) {
+		printk("Unable to complete write. Volume full.\n");
+		printk("Number of bytes written: [%d]\n", brw);
+		fs_close(fp);
+		return -1;
+	}
+
+	printk("Data successfully written!\n");
+	printk("Data written:\"%s\"\n\n", str);
+
+	return res;
+}
+
+static int read_test(ZFILE *fp, off_t ofs, size_t sz, char *read_buff)
+{
+	ssize_t brw;
+	int res;
+
+	res = fs_seek(fp, ofs, SEEK_SET);
+	if (res) {
+		printk("fs_seek failed [%d]\n", res);
+		fs_close(fp);
+		return res;
+	}
+
+	brw = fs_read(fp, read_buff, sz);
+	if (brw < 0) {
+		printk("Failed reading file [%d]\n", brw);
+		fs_close(fp);
+		return res;
+	}
+
+	printk("Data successfully read!\n");
+	read_buff[brw] = 0;
+	printk("Data read:\"%s\"\n\n", read_buff);
+
+	return res;
+}
+
+static int close_file(ZFILE *fp, const char *path)
+{
+	int res;
+
+	res = fs_close(fp);
+	if (res) {
+		printk("Error closing file [%d]\n", res);
+		return res;
+	}
+
+	printk("Closed file %s\n", path);
+
+	return res;
+}
+
+static int delete_test(const char *path)
+{
+	int res;
+
+	/* Delete the file and verify checking its status */
+	res = fs_unlink(path);
+	if (res) {
+		printk("Error deleting file [%d]\n", res);
+		return res;
+	}
+
+	/* Check if file was deleted */
+	if (check_file_dir_exists(path)) {
+		printk("Failed deleting %s\n", path);
+		return -1;
+	}
+
+	printk("File (%s) deleted successfully!\n", path);
+
+	return 0;
+}
+
+static void file_tests(void)
+{
+	ZFILE fp;
+	int res;
+	char read_buff[80];
+
+	res = open_file(&fp, TEST_FILE);
+	if (res) {
+		return;
+	}
+
+	res = write_test(&fp, 0, test_str);
+	if (res) {
+		return;
+	}
+
+	res = read_test(&fp, 0, strlen(test_str), read_buff);
+	if (res) {
+		return;
+	}
+
+	if (strcmp(test_str, read_buff)) {
+		printk("Error - Data read does not match data written\n");
+		return;
+	}
+
+	printk("Data read matches data written!\n");
+
+	res = close_file(&fp, TEST_FILE);
+	if (res) {
+		return;
+	}
+
+	res = delete_test(TEST_FILE);
+	if (res) {
+		return;
+	}
+}
+
+static int create_dir(const char *path)
+{
+	int res;
+
+	res = fs_mkdir(path);
+	if (res) {
+		printk("Error creating dir[%d]\n", res);
+		return res;
+	}
+
+	printk("Created dir %s!\n", path);
+
+	return 0;
+}
+
+/* Deletes files and sub directories one level deep */
+static int remove_dir(const char *path)
+{
+	int res;
+	ZDIR dp;
+	static struct zfs_dirent entry;
+	char file_path[80];
+
+	if (!check_file_dir_exists(path)) {
+		return 0;
+	}
+
+	res = fs_opendir(&dp, path);
+	if (res) {
+		printk("Error opening dir[%d]\n", res);
+		return res;
+	}
+
+	printk("\nRemoving files and sub directories in %s\n", path);
+	for (;;) {
+		res = fs_readdir(&dp, &entry);
+
+		/* entry.name[0] == 0 means end-of-dir */
+		if (res || entry.name[0] == 0) {
+			break;
+		}
+
+		/* Delete file or sub directory */
+
+		sprintf(file_path, "%s/%s", path, entry.name);
+		printk("Removing %s\n", file_path);
+
+		res = fs_unlink(file_path);
+		if (res) {
+			printk("Error deleting file/dir [%d]\n", res);
+			fs_closedir(&dp);
+			return res;
+		}
+	}
+
+	fs_closedir(&dp);
+
+	/* Remove the sub directory */
+	res = fs_unlink(path);
+	if (res) {
+		printk("Error removing dir [%d]\n", res);
+		return res;
+	}
+
+	printk("Removed dir %s!\n", path);
+
+	return 0;
+}
+
+static int list_dir(const char *path)
+{
+	int res;
+	ZDIR dp;
+	static struct zfs_dirent entry;
+
+	res = fs_opendir(&dp, path);
+	if (res) {
+		printk("Error opening dir[%d]\n", res);
+		return res;
+	}
+
+	printk("\nListing dir %s:\n", path);
+	for (;;) {
+		res = fs_readdir(&dp, &entry);
+
+		/* entry.name[0] == 0 means end-of-dir */
+		if (res || entry.name[0] == 0) {
+			break;
+		}
+		if (entry.type == DIR_ENTRY_DIR) {
+			printk("[DIR ] %s\n", entry.name);
+		} else {
+			printk("[FILE] %s (size = %d)\n",
+				entry.name, entry.size);
+		}
+	}
+
+	fs_closedir(&dp);
+
+	return 0;
+}
+
+static void dir_tests(void)
+{
+	ZFILE fp[2];
+	int res;
+
+	/* Remove sub dir if already exists */
+	res = remove_dir(TEST_SUB_DIR);
+	if (res) {
+		return;
+	}
+
+	/* Create a sub directory */
+	res = create_dir(TEST_SUB_DIR);
+	if (res) {
+		return;
+	}
+
+	/* Open or create files */
+
+	res = open_file(&fp[0], TEST_FILE);
+	if (res) {
+		return;
+	}
+
+	res = open_file(&fp[1], TEST_SUB_DIR "/" TEST_FILE);
+	if (res) {
+		return;
+	}
+
+	/* Write to files to check size info */
+	res = write_test(&fp[0], 0, "1");
+	if (res) {
+		return;
+	}
+
+	res = write_test(&fp[1], 0, "12");
+	if (res) {
+		return;
+	}
+
+	/* Close the files in the directories */
+
+	res = close_file(&fp[0], TEST_FILE);
+	if (res) {
+		return;
+	}
+
+	res = close_file(&fp[1], TEST_SUB_DIR "/" TEST_FILE);
+	if (res) {
+		return;
+	}
+
+	/* List the files in root and sub dir */
+	res = list_dir("/");
+	if (res) {
+		return;
+	}
+
+	res = list_dir(TEST_SUB_DIR);
+	if (res) {
+		return;
+	}
+
+	/* Remove sub dir */
+	res = remove_dir(TEST_SUB_DIR);
+	if (res) {
+		return;
+	}
+}

samples/fs/fat_fs/testcase.ini

@@ -0,0 +1,13 @@
+[test-nano]
+tags = fs
+build_only = true
+arch_whitelist = x86
+platform_whitelist = qemu_x86
+kernel = nano
+
+[test-micro]
+tags = fs
+build_only = true
+arch_whitelist = x86
+platform_whitelist = qemu_x86
+kernel = micro