--- /dev/null
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2011 New Dream Network
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+/*
+ * direct_io_test
+ *
+ * This test does some I/O using O_DIRECT.
+ *
+ * Semantics of O_DIRECT can be found at http://lwn.net/Articles/348739/
+ *
+ */
+
+static int g_num_pages = 100;
+
+static int g_duration = 10;
+
+struct chunk {
+ uint64_t offset;
+ uint64_t pad0;
+ uint64_t pad1;
+ uint64_t pad2;
+ uint64_t pad3;
+ uint64_t pad4;
+ uint64_t pad5;
+ uint64_t not_offset;
+} __attribute__((packed));
+
+static int page_size;
+
+static char temp_file[] = "direct_io_temp_file_XXXXXX";
+
+static int safe_write(int fd, const void *buf, signed int len)
+{
+ const char *b = (const char*)buf;
+ /* Handle EINTR and short writes */
+ while (1) {
+ int res = write(fd, b, len);
+ if (res < 0) {
+ int err = errno;
+ if (err != EINTR) {
+ return err;
+ }
+ }
+ len -= res;
+ b += res;
+ if (len <= 0)
+ return 0;
+ }
+}
+
+static int do_read(int fd, char *buf, int buf_sz)
+{
+ /* We assume no short reads or EINTR. It's not really clear how
+ * those things interact with O_DIRECT. */
+ int ret = read(fd, buf, buf_sz);
+ if (ret < 0) {
+ int err = errno;
+ printf("do_read: error: %d (%s)\n", err, strerror(err));
+ return err;
+ }
+ if (ret != buf_sz) {
+ printf("do_read: short read\n");
+ return -EIO;
+ }
+ return 0;
+}
+
+static int setup_temp_file(void)
+{
+ int fd;
+ int64_t num_chunks, i;
+
+ if (page_size % sizeof(struct chunk)) {
+ printf("setup_big_file: page_size doesn't divide evenly "
+ "into data blocks.\n");
+ return -EINVAL;
+ }
+
+ fd = mkstemp(temp_file);
+ if (fd < 0) {
+ int err = errno;
+ printf("setup_big_file: mkostemps failed with error %d\n", err);
+ return err;
+ }
+
+ num_chunks = g_num_pages * (page_size / sizeof(struct chunk));
+ for (i = 0; i < num_chunks; ++i) {
+ int ret;
+ struct chunk c;
+ memset(&c, 0, sizeof(c));
+ c.offset = i * sizeof(struct chunk);
+ c.pad0 = 0;
+ c.pad1 = 1;
+ c.pad2 = 2;
+ c.pad3 = 3;
+ c.pad4 = 4;
+ c.pad5 = 5;
+ c.not_offset = ~c.offset;
+ ret = safe_write(fd, &c, sizeof(struct chunk));
+ if (ret) {
+ printf("setup_big_file: safe_write failed with "
+ "error: %d\n", ret);
+ TEMP_FAILURE_RETRY(close(fd));
+ unlink(temp_file);
+ return ret;
+ }
+ }
+ TEMP_FAILURE_RETRY(close(fd));
+ return 0;
+}
+
+static int verify_chunk(const struct chunk *c, uint64_t offset)
+{
+ if (c->offset != offset) {
+ printf("verify_chunk(%" PRId64 "): bad offset value (got: %"
+ PRId64 ", expected: %" PRId64 "\n", offset, c->offset, offset);
+ return EIO;
+ }
+ if (c->pad0 != 0) {
+ printf("verify_chunk(%" PRId64 "): bad pad0 value\n", offset);
+ return EIO;
+ }
+ if (c->pad1 != 1) {
+ printf("verify_chunk(%" PRId64 "): bad pad1 value\n", offset);
+ return EIO;
+ }
+ if (c->pad2 != 2) {
+ printf("verify_chunk(%" PRId64 "): bad pad2 value\n", offset);
+ return EIO;
+ }
+ if (c->pad3 != 3) {
+ printf("verify_chunk(%" PRId64 "): bad pad3 value\n", offset);
+ return EIO;
+ }
+ if (c->pad4 != 4) {
+ printf("verify_chunk(%" PRId64 "): bad pad4 value\n", offset);
+ return EIO;
+ }
+ if (c->pad5 != 5) {
+ printf("verify_chunk(%" PRId64 "): bad pad5 value\n", offset);
+ return EIO;
+ }
+ if (c->not_offset != ~offset) {
+ printf("verify_chunk(%" PRId64 "): bad not_offset value\n",
+ offset);
+ return EIO;
+ }
+ return 0;
+}
+
+static int do_o_direct_reads(void)
+{
+ int fd, ret;
+ unsigned int i;
+ void *buf = 0;
+ time_t cur_time, end_time;
+ ret = posix_memalign(&buf, page_size, page_size);
+ if (ret) {
+ printf("do_o_direct_reads: posix_memalign returned %d\n", ret);
+ goto done;
+ }
+
+ fd = open(temp_file, O_RDONLY | O_DIRECT);
+ if (fd < 0) {
+ ret = errno;
+ printf("do_o_direct_reads: error opening fd: %d\n", ret);
+ goto free_buf;
+ }
+
+ // read the first chunk and see if it looks OK
+ ret = do_read(fd, buf, page_size);
+ if (ret)
+ goto close_fd;
+ ret = verify_chunk((struct chunk*)buf, 0);
+ if (ret)
+ goto close_fd;
+
+ // read some random chunks and see how they look
+ cur_time = time(NULL);
+ end_time = cur_time + g_duration;
+ i = 0;
+ do {
+ time_t next_time;
+ uint64_t offset;
+ int page;
+ unsigned int seed;
+
+ seed = i++;
+ page = rand_r(&seed) % g_num_pages;
+ offset = page;
+ offset *= page_size;
+ if (lseek64(fd, offset, SEEK_SET) == -1) {
+ int err = errno;
+ printf("lseek64(%" PRId64 ") failed: error %d (%s)\n",
+ offset, err, strerror(err));
+ goto close_fd;
+ }
+ ret = do_read(fd, buf, page_size);
+ if (ret)
+ goto close_fd;
+ ret = verify_chunk((struct chunk*)buf, offset);
+ if (ret)
+ goto close_fd;
+ next_time = time(NULL);
+ if (next_time > cur_time) {
+ printf(".");
+ }
+ cur_time = next_time;
+ } while (time(NULL) < end_time);
+
+ printf("\ndo_o_direct_reads: SUCCESS\n");
+close_fd:
+ TEMP_FAILURE_RETRY(close(fd));
+free_buf:
+ free(buf);
+done:
+ return ret;
+}
+
+static void usage(char *argv0)
+{
+ printf("%s: tests direct I/O\n", argv0);
+ printf("-d <seconds>: sets duration to <seconds>\n");
+ printf("-h: this help\n");
+ printf("-p <pages>: sets number of pages to allocate\n");
+}
+
+static void parse_args(int argc, char *argv[])
+{
+ int c;
+ while ((c = getopt (argc, argv, "d:hp:")) != -1) {
+ switch (c) {
+ case 'd':
+ g_duration = atoi(optarg);
+ if (g_duration <= 0) {
+ printf("tried to set invalid value of "
+ "g_duration: %d\n", g_num_pages);
+ exit(1);
+ }
+ break;
+ case 'h':
+ usage(argv[0]);
+ exit(0);
+ break;
+ case 'p':
+ g_num_pages = atoi(optarg);
+ if (g_num_pages <= 0) {
+ printf("tried to set invalid value of "
+ "g_num_pages: %d\n", g_num_pages);
+ exit(1);
+ }
+ break;
+ case '?':
+ usage(argv[0]);
+ exit(1);
+ break;
+ default:
+ usage(argv[0]);
+ exit(1);
+ break;
+ }
+ }
+}
+
+int main(int argc, char *argv[])
+{
+ int ret;
+
+ parse_args(argc, argv);
+
+ setvbuf(stdout, NULL, _IONBF, 0);
+
+ page_size = getpagesize();
+
+ ret = setup_temp_file();
+ if (ret) {
+ printf("setup_temp_file failed with error %d\n", ret);
+ goto done;
+ }
+
+ ret = do_o_direct_reads();
+ if (ret) {
+ printf("do_o_direct_reads failed with error %d\n", ret);
+ goto unlink_temp_file;
+ }
+
+unlink_temp_file:
+ unlink(temp_file);
+done:
+ return ret;
+}
Code Review / stor4nfv.git / blobdiff