puncture_fs: A new utility that is used with fs benchmarking tools.
The tools fills up the filesystem completely then removes a set of files
of predefined size to free up some predefined non-contiguous free space.
It is used with benchmarking tools like fio to collect metrics on a used filesystem with sparse free space.
Change-Id: Ieb1d38c0f95c51462060e541a662c378b79d81fb
diff --git a/puncture_fs/Android.mk b/puncture_fs/Android.mk
new file mode 100644
index 0000000..0b79cca
--- /dev/null
+++ b/puncture_fs/Android.mk
@@ -0,0 +1,31 @@
+# Copyright (C) 2014 The Android Open Source Project
+#
+# 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.
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := puncture_fs.c
+
+LOCAL_C_INCLUDES += system/core/logwrapper/include
+
+LOCAL_SHARED_LIBRARIES := libc liblog liblogwrap
+
+LOCAL_MODULE := puncture_fs
+
+LOCAL_MODULE_TAGS := debug
+
+LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
+
+include $(BUILD_EXECUTABLE)
diff --git a/puncture_fs/puncture_fs.c b/puncture_fs/puncture_fs.c
new file mode 100644
index 0000000..1c0fa0a
--- /dev/null
+++ b/puncture_fs/puncture_fs.c
@@ -0,0 +1,261 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * 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 <assert.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <logwrap/logwrap.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <utils/Log.h>
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+
+#define MAX_IO_WRITE_CHUNK_SIZE 0x100000
+
+#ifndef min
+#define min(a,b) ((a) < (b) ? (a) : (b))
+#endif
+
+typedef unsigned long u64;
+
+static void usage(const char * const progname) {
+ fprintf(stderr,
+ "Usage: %s [-s <seed>] -h <hole size in bytes> -t <total hole size in bytes> "
+ "path\n",
+ progname);
+}
+
+static u64 get_free_space(const char * const path) {
+ struct statvfs s;
+
+ if (statvfs(path, &s) < 0) {
+ fprintf(stderr, "\nerrno: %d. Failed to get free disk space on %s\n",
+ errno, path);
+ return 0;
+ } else {
+ return (u64)s.f_bsize * (u64)s.f_bfree;
+ }
+}
+
+static u64 get_random_num(const u64 start, const u64 end) {
+ if (end - start <= 0)
+ return start;
+ assert(RAND_MAX >= 0x7FFFFFFF);
+ if ((end - start) > 0x7FFFFFFF)
+ return start + (((u64)random() << 31) | (u64)random()) % (end - start);
+ return start + (random() % (end - start));
+}
+
+static char get_random_char() {
+ return 'A' + random() % ('Z' - 'A');
+}
+
+static bool create_unique_file(const char * const dir_path, const u64 size,
+ const u64 id, char * const base,
+ const u64 base_length) {
+ u64 length = 0;
+ int fd;
+ char file_path[FILENAME_MAX];
+ bool ret = true;
+
+ base[random() % min(base_length, size)] = get_random_char();
+
+ sprintf(file_path, "%s/file_%lu", dir_path, id);
+ fd = open(file_path, O_WRONLY | O_CREAT | O_SYNC, 0777);
+ if (fd < 0) {
+ // We suppress ENOSPC erros as that is common as we approach the
+ // last few MBs of the fs as we don't account for the size of the newly
+ // added meta data after the initial free space computation.
+ if (errno != 28) {
+ fprintf(stderr, "\nerrno: %d. Failed to create %s\n", errno, file_path);
+ }
+ return false;
+ }
+ while (length + base_length < size) {
+ if (write(fd, base, base_length) < 0) {
+ if (errno != 28) {
+ fprintf(stderr, "\nerrno: %d. Failed to write %lu bytes to %s\n",
+ errno, base_length, file_path);
+ }
+ ret = false;
+ goto done;
+ }
+ length += base_length;
+ }
+ if (write(fd, base, size - length) < 0) {
+ if (errno != 28) {
+ fprintf(stderr, "\nerrno: %d. Failed to write last %lu bytes to %s\n",
+ errno, size - length, file_path);
+ }
+ ret = false;
+ goto done;
+ }
+done:
+ if (close(fd) < 0) {
+ fprintf(stderr, "\nFailed to close %s\n", file_path);
+ ret = false;
+ }
+ return ret;
+}
+
+static bool create_unique_dir(char *dir, const char * const root_path) {
+ char random_string[15];
+ int i;
+
+ for (i = 0; i < 14; ++i) {
+ random_string[i] = get_random_char();
+ }
+ random_string[14] = '\0';
+
+ sprintf(dir, "%s/%s", root_path, random_string);
+
+ if (mkdir(dir, 0777) < 0) {
+ fprintf(stderr, "\nerrno: %d. Failed to create %s\n", errno, dir);
+ return false;
+ }
+ return true;
+}
+
+static bool puncture_fs (const char * const path, const u64 total_size,
+ const u64 hole_size, const u64 total_hole_size) {
+ u64 increments = (hole_size * total_size) / total_hole_size;
+ u64 hole_max;
+ u64 starting_max = 0;
+ u64 ending_max = increments;
+ char stay_dir[FILENAME_MAX], delete_dir[FILENAME_MAX];
+ char *rm_bin_argv[] = { "/system/bin/rm", "-rf", ""};
+ u64 file_id = 1;
+ char *base_file_data;
+ u64 i = 0;
+
+ if (!create_unique_dir(stay_dir, path) ||
+ !create_unique_dir(delete_dir, path)) {
+ return false;
+ }
+
+ base_file_data = (char*) malloc(MAX_IO_WRITE_CHUNK_SIZE);
+ for (i = 0; i < MAX_IO_WRITE_CHUNK_SIZE; ++i) {
+ base_file_data[i] = get_random_char();
+ }
+ fprintf(stderr, "\n");
+ while (ending_max <= total_size) {
+ fprintf(stderr, "\rSTAGE 1/2: %d%% Complete",
+ (int) (100.0 * starting_max / total_size));
+ hole_max = get_random_num(starting_max, ending_max);
+
+ create_unique_file(stay_dir,
+ hole_max - starting_max,
+ file_id++,
+ base_file_data,
+ MAX_IO_WRITE_CHUNK_SIZE);
+ create_unique_file(delete_dir,
+ hole_size,
+ file_id++,
+ base_file_data,
+ MAX_IO_WRITE_CHUNK_SIZE);
+
+ starting_max = hole_max + hole_size;
+ ending_max += increments;
+ }
+ create_unique_file(stay_dir,
+ (ending_max - increments - starting_max),
+ file_id++,
+ base_file_data,
+ MAX_IO_WRITE_CHUNK_SIZE);
+ fprintf(stderr, "\rSTAGE 1/2: 100%% Complete\n");
+ fprintf(stderr, "\rSTAGE 2/2: 0%% Complete");
+ free(base_file_data);
+ rm_bin_argv[2] = delete_dir;
+ if (android_fork_execvp_ext(ARRAY_SIZE(rm_bin_argv), rm_bin_argv,
+ NULL, 1, LOG_KLOG, 0, NULL) < 0) {
+ fprintf(stderr, "\nFailed to delete %s\n", rm_bin_argv[2]);
+ return false;
+ }
+ fprintf(stderr, "\rSTAGE 2/2: 100%% Complete\n");
+ return true;
+}
+
+int main (const int argc, char ** const argv) {
+ int opt;
+ int mandatory_opt;
+ char *path = NULL;
+ int seed = time(NULL);
+
+ u64 total_size = 0;
+ u64 hole_size = 0;
+ u64 total_hole_size = 0;
+
+ mandatory_opt = 2;
+ while ((opt = getopt(argc, argv, "s:h:t:")) != -1) {
+ switch(opt) {
+ case 's':
+ seed = atoi(optarg);
+ break;
+ case 'h':
+ hole_size = atoll(optarg);
+ mandatory_opt--;
+ break;
+ case 't':
+ total_hole_size = atoll(optarg);
+ mandatory_opt--;
+ break;
+ default:
+ usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+ }
+ if (mandatory_opt) {
+ usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+ if (optind >= argc) {
+ fprintf(stderr, "\nExpected path name after options.\n");
+ usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+ path = argv[optind++];
+
+ if (optind < argc) {
+ fprintf(stderr, "\nUnexpected argument: %s\n", argv[optind]);
+ usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ srandom(seed);
+ fprintf(stderr, "\nRandom seed is: %d\n", seed);
+
+ total_size = get_free_space(path);
+ if (!total_size) {
+ exit(EXIT_FAILURE);
+ }
+ if (total_size < total_hole_size || total_hole_size < hole_size) {
+ fprintf(stderr, "\nInvalid sizes: total available size should be "
+ "larger than total hole size which is larger than "
+ "hole size\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (!puncture_fs(path, total_size, hole_size, total_hole_size)) {
+ exit(EXIT_FAILURE);
+ }
+ return 0;
+}