diff options
Diffstat (limited to 'src/fsync-tester.c')
| -rw-r--r-- | src/fsync-tester.c | 537 |
1 files changed, 537 insertions, 0 deletions
diff --git a/src/fsync-tester.c b/src/fsync-tester.c new file mode 100644 index 00000000..f0875fc9 --- /dev/null +++ b/src/fsync-tester.c @@ -0,0 +1,537 @@ +#include <sys/time.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> + +static int test_fd; +static char *buf; +static char *fname; + +/* + * Just creates a random file, overwriting the file in a random number of loops + * and fsyncing between each loop. + */ +static int test_one(int *max_blocks) +{ + int loops = (random() % 20) + 5; + + lseek(test_fd, 0, SEEK_SET); + while (loops--) { + int character = (random() % 126) + 33; /* printable character */ + int blocks = (random() % 100) + 1; + + if (blocks > *max_blocks) + *max_blocks = blocks; + lseek(test_fd, 0, SEEK_SET); + memset(buf, character, 4096); + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed, test results will be " + "invalid: %d\n", errno); + return 1; + } + + while (blocks--) { + if (write(test_fd, buf, 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + } + } + + return 0; +} + +/* + * Preallocate a randomly sized file and then overwrite the entire thing and + * then fsync. + */ +static int test_two(int *max_blocks) +{ + int blocks = (random() % 1024) + 1; + int character = (random() % 126) + 33; + + *max_blocks = blocks; + + if (fallocate(test_fd, 0, 0, blocks * 4096)) { + fprintf(stderr, "Error fallocating %d (%s)\n", errno, + strerror(errno)); + return 1; + } + + lseek(test_fd, 0, SEEK_SET); + memset(buf, character, 4096); + while (blocks--) { + if (write(test_fd, buf, 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + } + + return 0; +} + +static void drop_all_caches() +{ + char value[] = "3\n"; + int fd; + + if ((fd = open("/proc/sys/vm/drop_caches", O_WRONLY)) < 0) { + fprintf(stderr, "Error opening drop caches: %d\n", errno); + return; + } + + write(fd, value, sizeof(value)-1); + close(fd); +} + +/* + * Randomly write inside of a file, either creating a sparse file or prealloc + * the file and randomly write within it, depending on the prealloc flag + */ +static int test_three(int *max_blocks, int prealloc, int rand_fsync, + int do_sync, int drop_caches) +{ + int size = (random() % 2048) + 4; + int blocks = size / 2; + int sync_block = blocks / 2; + int rand_sync_interval = (random() % blocks) + 1; + int character = (random() % 126) + 33; + + if (prealloc && fallocate(test_fd, 0, 0, size * 4096)) { + fprintf(stderr, "Error fallocating %d (%s)\n", errno, + strerror(errno)); + return 1; + } + + if (prealloc) + *max_blocks = size; + + memset(buf, character, 4096); + while (blocks--) { + int block = (random() % size); + + if ((block + 1) > *max_blocks) + *max_blocks = block + 1; + + if (rand_fsync && !(blocks % rand_sync_interval)) { + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed, test results " + "will be invalid: %d\n", errno); + return 1; + } + } + + /* Force a transaction commit in between just for fun */ + if (blocks == sync_block && (do_sync || drop_caches)) { + if (do_sync) + sync(); + else + sync_file_range(test_fd, 0, 0, + SYNC_FILE_RANGE_WRITE| + SYNC_FILE_RANGE_WAIT_AFTER); + + if (drop_caches) { + close(test_fd); + drop_all_caches(); + test_fd = open(fname, O_RDWR); + if (test_fd < 0) { + test_fd = 0; + fprintf(stderr, "Error re-opening file: %d\n", + errno); + return 1; + } + } + } + + if (pwrite(test_fd, buf, 4096, block * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + } + + return 0; +} + +static void timeval_subtract(struct timeval *result,struct timeval *x, + struct timeval *y) +{ + if (x->tv_usec < y->tv_usec) { + int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1; + y->tv_usec -= 1000000 * nsec; + y->tv_sec += nsec; + } + + if (x->tv_usec - y->tv_usec > 1000000) { + int nsec = (x->tv_usec - y->tv_usec) / 1000000; + y->tv_usec += 1000000 * nsec; + y->tv_sec -= nsec; + } + + result->tv_sec = x->tv_sec - y->tv_sec; + result->tv_usec = x->tv_usec - y->tv_usec; +} + +static int test_four(int *max_blocks) +{ + size_t size = 2621440; /* 10 gigabytes */ + size_t blocks = size / 2; + size_t sync_block = blocks / 8; /* fsync 8 times */ + int character = (random() % 126) + 33; + struct timeval start, end, diff; + + memset(buf, character, 4096); + while (blocks--) { + off_t block = (random() % size); + + if ((block + 1) > *max_blocks) + *max_blocks = block + 1; + + if ((blocks % sync_block) == 0) { + if (gettimeofday(&start, NULL)) { + fprintf(stderr, "Error getting time: %d\n", + errno); + return 1; + } + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed, test results " + "will be invalid: %d\n", errno); + return 1; + } + if (gettimeofday(&end, NULL)) { + fprintf(stderr, "Error getting time: %d\n", + errno); + return 1; + } + timeval_subtract(&diff, &end, &start); + printf("Fsync time was %ds and %dus\n", + (int)diff.tv_sec, (int)diff.tv_usec); + } + + if (pwrite(test_fd, buf, 4096, block * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + } + + return 0; +} + +static int test_five() +{ + int character = (random() % 126) + 33; + int runs = (random() % 100) + 1; + int i; + + memset(buf, character, 3072); + for (i = 0; i < runs; i++) { + size_t write_size = (random() % 3072) + 1; + + if (pwrite(test_fd, buf, write_size, 0) < write_size) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + + if ((i % 8) == 0) { + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed, test results " + "will be invalid: %d\n", errno); + return 1; + } + } + } + + return 0; +} + +/* + * Reproducer for something like this + * + * [data][prealloc][data] + * + * and then in the [prealloc] section we have + * + * [ pre ][pre][ pre ] + * [d][pp][dd][ppp][d][ppp][d] + * + * where each letter represents on block of either data or prealloc. + * + * This explains all the weirdly specific numbers. + */ +static int test_six() +{ + int character = (random() % 126) + 33; + int i; + + memset(buf, character, 4096); + + /* Write on either side of the file, leaving a hole in the middle */ + for (i = 0; i < 10; i++) { + if (pwrite(test_fd, buf, 4096, i * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + } + + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed %d\n", errno); + return 1; + } + + /* + * The test fs I had the prealloc extent was 13 4k blocks long so I'm + * just using that to give myself the best chances of reproducing. + */ + for (i = 23; i < 33; i++) { + if (pwrite(test_fd, buf, 4096, i * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + } + + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed %d\n", errno); + return 1; + } + + if (fallocate(test_fd, 0, 10 * 4096, 4 * 4096)) { + fprintf(stderr, "Error fallocating %d\n", errno); + return 1; + } + + if (fallocate(test_fd, 0, 14 * 4096, 5 * 4096)) { + fprintf(stderr, "Error fallocating %d\n", errno); + return 1; + } + + if (fallocate(test_fd, 0, 19 * 4096, 4 * 4096)) { + fprintf(stderr, "Error fallocating %d\n", errno); + return 1; + } + + if (pwrite(test_fd, buf, 4096, 10 * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed %d\n", errno); + return 1; + } + + for (i = 13; i < 15; i++) { + if (pwrite(test_fd, buf, 4096, i * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + } + + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed %d\n", errno); + return 1; + } + + if (pwrite(test_fd, buf, 4096, 18 * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed %d\n", errno); + return 1; + } + + if (pwrite(test_fd, buf, 4096, 22 * 4096) < 4096) { + fprintf(stderr, "Short write %d\n", errno); + return 1; + } + + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed %d\n", errno); + return 1; + } + + return 0; +} + +static void usage() +{ + printf("Usage fsync-tester [-s <seed>] [-r] [-d] -t <test-num> <filename>\n"); + printf(" -s seed : seed for teh random map generator (defaults to reading /dev/urandom)\n"); + printf(" -r : don't reboot the box immediately\n"); + printf(" -d : use O_DIRECT\n"); + printf(" -t test : test nr to run, required\n"); + exit(1); +} + +int main(int argc, char **argv) +{ + int opt; + int fd; + int max_blocks = 0; + char *endptr; + unsigned int seed = 123; + int reboot = 0; + int direct_io = 0; + long int test = 1; + long int tmp; + int ret = 0; + int flags = O_RDWR|O_CREAT|O_TRUNC; + + if (argc < 2) + usage(); + + fd = open("/dev/urandom", O_RDONLY); + if (fd >= 0) { + read(fd, &seed, sizeof(seed)); + close(fd); + } + + while ((opt = getopt(argc, argv, "s:rdt:")) != -1) { + switch (opt) { + case 's': + tmp = strtol(optarg, &endptr, 10); + if (tmp == LONG_MAX || endptr == optarg) + usage(); + seed = tmp; + break; + case 'r': + reboot = 1; + break; + case 'd': + direct_io = 1; + break; + case 't': + test = strtol(optarg, &endptr, 10); + if (test == LONG_MAX || endptr == optarg) + usage(); + break; + default: + usage(); + } + } + + if (optind >= argc) + usage(); + + fname = argv[optind]; + if (!fname) + usage(); + + printf("Random seed is %u\n", seed); + srandom(seed); + + if (direct_io) { + flags |= O_DIRECT; + ret = posix_memalign((void **)&buf, getpagesize(), 4096); + if (ret) + buf = NULL; + } else { + buf = malloc(4096); + } + + if (!buf) { + fprintf(stderr, "Error allocating buf: %d\n", errno); + return 1; + } + + test_fd = open(fname, flags, 0644); + if (test_fd < 0) { + fprintf(stderr, "Error opening file %d (%s)\n", errno, + strerror(errno)); + return 1; + } + + switch (test) { + case 1: + ret = test_one(&max_blocks); + break; + case 2: + ret = test_two(&max_blocks); + break; + case 3: + ret = test_three(&max_blocks, 0, 0, 0, 0); + break; + case 4: + ret = test_three(&max_blocks, 1, 0, 0, 0); + break; + case 5: + ret = test_three(&max_blocks, 0, 1, 0, 0); + break; + case 6: + ret = test_three(&max_blocks, 1, 1, 0, 0); + break; + case 7: + ret = test_three(&max_blocks, 0, 0, 1, 0); + break; + case 8: + ret = test_three(&max_blocks, 1, 0, 1, 0); + break; + case 9: + ret = test_three(&max_blocks, 0, 1, 1, 0); + break; + case 10: + ret = test_three(&max_blocks, 1, 1, 1, 0); + break; + case 11: + ret = test_three(&max_blocks, 0, 0, 0, 1); + break; + case 12: + ret = test_three(&max_blocks, 0, 1, 0, 1); + break; + case 13: + ret = test_three(&max_blocks, 0, 0, 1, 1); + break; + case 14: + ret = test_three(&max_blocks, 0, 1, 1, 1); + break; + case 15: + ret = test_three(&max_blocks, 1, 0, 0, 1); + break; + case 16: + ret = test_three(&max_blocks, 1, 1, 0, 1); + break; + case 17: + ret = test_three(&max_blocks, 1, 0, 1, 1); + break; + case 18: + ret = test_three(&max_blocks, 1, 1, 1, 1); + break; + case 19: + ret = test_five(); + break; + case 20: + ret = test_six(); + break; + case 21: + /* + * This is just a perf test, keep moving it down so it's always + * the last test option. + */ + reboot = 0; + ret = test_four(&max_blocks); + goto out; + default: + usage(); + } + + if (ret) + goto out; + + if (fsync(test_fd)) { + fprintf(stderr, "Fsync failed, test results will be invalid: " + "%d\n", errno); + return 1; + } + if (reboot) + system("reboot -fn"); +out: + free(buf); + close(test_fd); + return ret; +} |