diff options
Diffstat (limited to 'qa/workunits/direct_io/direct_io_test.c')
| -rw-r--r-- | qa/workunits/direct_io/direct_io_test.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/qa/workunits/direct_io/direct_io_test.c b/qa/workunits/direct_io/direct_io_test.c new file mode 100644 index 000000000..ccfbbb860 --- /dev/null +++ b/qa/workunits/direct_io/direct_io_test.c @@ -0,0 +1,312 @@ +/* + * 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; +} |