any comments?
On Fri, Apr 4, 2014 at 11:09 PM, Zhi Yong Wu <zwu.kernel@xxxxxxxxx> wrote:
> HI
>
> When i try something on XFS filesytem, i hit one issue as below:
>
> One main task create multiple threads at first, Then it will dio
> random write some files with random offset and length for each thread.
> When those files get ready, those multiple threads will bufferio read
> them and check if the data are same as their corresponding buffer. In
> theory, they should be same, but the actual result isn't what we
> expect
>
> By the way, i did the same try on ext3 filesystem, but didn't get any
> such issue.
>
> Below is the test code:
>
> #include <errno.h>
> #include <string.h>
> #include <time.h>
> #include <pthread.h>
> #include <assert.h>
> #include <stdlib.h>
> #include <stdio.h>
> #include <libaio.h>
> #include <sys/stat.h>
> #include <sys/types.h>
> #include <syscall.h>
> #include <fcntl.h>
> #include <libaio.h>
> #include <string>
> #include <vector>
>
> using namespace std;
>
> #define AIO_BLKSIZE 4096
> #define AIO_MAXIO 64
>
> static long gettid()
> {
> return static_cast<long>(pthread_self());
> }
>
> static void* aioThreadWrapper(void* arg);
>
> class DioTest;
> struct cbParam {
> cbParam(DioTest* p, int fileseq) :p_(p), fileseq_(fileseq) {}
>
> DioTest* p_;
> int fileseq_;
> };
>
>
> class DioTest
> {
> public:
> DioTest(const char* name) {
> filename = name;
> memset(&myctx, 0, sizeof(myctx));
> io_queue_init(AIO_MAXIO, &myctx);
> pthread_t tid;
> pthread_create(&tid, NULL, aioThreadWrapper, this);
> }
>
> void wr_done(int fileseq, struct iocb *iocb, long res, long res2) {
> close(iocb->aio_fildes);
>
> if (res2 != 0) {
> printf("aio write error n");
> abort();
> }
> if (res != iocb->u.c.nbytes) {
> printf("write missed bytes expect %ld got %ld n",
> iocb->u.c.nbytes, res);
> abort();
> }
> size_t length = iocb->u.c.nbytes;
> size_t offset = iocb->u.c.offset;
> char path[1024];
> snprintf(path, sizeof(path), "%s%d", filename, fileseq);
> int fd = open(path, O_RDONLY);
> assert(fd >= 0);
> char* readbuf = (char*)malloc(length);
> assert(readbuf);
>
> memset(readbuf, 0, length);
> ssize_t ret = pread(fd, readbuf, length, offset);
> assert (ret == length);
> close(fd);
>
> int cmp = memcmp(readbuf, iocb->u.c.buf, length);
> if (cmp != 0)
> {
> printf("tid=%ld data dismatch.cmp=%d file=%s
> offset=%lu length=%lu!\n",
> gettid(), cmp, path, offset, length);
> abort();
> }
> printf("tid=%ld check=success file=%s offset=%lu length=%lu\n",
> gettid(), path, offset, length);
>
> free(iocb->u.c.buf);
> free(iocb);
> free(readbuf);
> }
>
> bool writeRequest(int fileseq, size_t offset, size_t length) {
> struct iocb *io = (struct iocb *)malloc(sizeof(struct iocb));
> assert (io);
> char path[1024];
> snprintf(path, sizeof(path), "%s%d", filename, fileseq);
> int fd = open(path, O_RDWR|O_DIRECT|O_CREAT, S_IWUSR | S_IRUSR);
> assert (fd >= 0);
> void* buf=NULL;
> int ret = posix_memalign(&buf, getpagesize(), length);
> assert(ret == 0);
> memset(buf, 'a', length);
> io_prep_pwrite(io, fd, buf, length, offset);
> io->data = new cbParam(this, fileseq);
>
> int rc = io_submit(myctx, 1, &io);
> if (rc < 0){
> printf("tid=%ld io_submit fail.file=%s offset=%lu
> length=%lu ret=%d errno=%s\n",
> gettid(), path, offset, length, ret, strerror(errno));
> close(fd);
> free(buf);
> delete (cbParam*)(io->data);
> free(io);
> return false;
> }
> assert (rc != 0);
> printf("tid=%ld file=%s offset=%lu length=%lu\n",gettid(),
> path, offset, length);
> return true;
> }
>
> void aioThread() {
> while (true)
> {
> struct io_event events[AIO_MAXIO];
> io_callback_t cb;
> int ret = io_getevents(myctx, 1, AIO_MAXIO, events, NULL);
> printf("tid=%ld %d io_request completed \n", gettid(), ret);
>
> for (int i = 0; i < ret; i++) {
> struct iocb *io = events[i].obj;
> printf("tid=%ld events[%d]res = %ld, res2 = %ld\n",
> gettid(), i, events[i].res, events[i].res2);
>
> cbParam* param = (cbParam*)io->data;
> DioTest* p = param->p_;
> p->wr_done(param->fileseq_, io, events[i].res,
> events[i].res2);
> delete param;
> }
> }
> }
> private:
> io_context_t myctx;
> const char* filename;
> };
>
> static void* aioThreadWrapper(void* arg)
> {
> DioTest* p = (DioTest*)arg;
> p->aioThread();
> return NULL;
> }
>
> int main(int args, char *argv[])
> {
> if (args < 2) {
> printf("./%s filename", argv[0]);
> exit(1);
> }
> const char* filename = argv[1];
> srand(time(NULL));
> vector<DioTest*> dioTests;
> const int threadNumber = 9;
>
> for (int i = 0; i < threadNumber; ++i) {
> dioTests.push_back(new DioTest(filename));
> }
>
> while (true) {
> size_t offset = (rand() % (64*1024*1024/AIO_BLKSIZE)) * AIO_BLKSIZE;
> size_t length = 0;
> while (length == 0) {
> length = abs(static_cast<int>(rand()*1.0/RAND_MAX*16))*AIO_BLKSIZE;
> }
>
> int seq = rand() % 100;
> DioTest* p = dioTests[rand() % threadNumber];
> for (int i = 0; i < 4; ++i){
> p->writeRequest(seq, offset, length);
> offset += (length + 4096);
> }
> usleep(rand() % 10000);
> }
> return 0;
> }
>
>
> --
> Regards,
>
> Zhi Yong Wu
--
Regards,
Zhi Yong Wu
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