Question

尝试让不同的 Linux节点上的多个进程写入Windows共享文件夹中的共享CSV文件。

我通过在不同节点上启动2个进程来测试它是否有效，每个节点都向文件追加10k行。然后我检查行数是否为20k。不幸的是，行数几乎总是小于那个。我正在使用Linux 3.0.51和Windows Server 2008 R2。但是，锁定多个进程在 1节点内的确可以使用flock（），但不能用于fcntl（）。

以下是我尝试过的其他一些事情：

使用NFS - 确实有效！（有时行数是19999）
使用Linux内核4.10并挂载为SMB 3.02 - 不起作用
使用Samba作为服务器 - 即使使用严格锁定= yes也不起作用如下所述：

https://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/locking.html

有没有人让它工作或知道无法完成（以及配置）？这是我的测试程序：

#include <unistd.h>
#include <fcntl.h>
#include <iostream>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <sys/file.h>
#include <boost/interprocess/sync/file_lock.hpp>
// method 0: fcntl() - works for NFS and across multiple nodes, but not for CIFS/SMB
// method 1: flock() - works for SMB within 1 node, but not accross multiple nodes
// method 2: Boost   (internally uses fcntl)
#define METHOD 1
using namespace std;
class FileLock
{
public:
#if METHOD == 2
  FileLock(const char *path) : lock(path)
  {
  }
#else
  FileLock(int f)
  {
    file = f;
#if METHOD == 0
    lock.l_whence = SEEK_SET;
    lock.l_start = 0;
    lock.l_len = 0;
#endif
  }
#endif
  bool Lock()
  {
#if METHOD == 0
    lock.l_type = F_WRLCK;
    return fcntl(file, F_SETLKW, &lock) == 0;
#elif METHOD == 1
    return flock(file, LOCK_EX) == 0;
#elif METHOD == 2
    lock.lock();
    return true;
#endif
  }
  bool Unlock()
  {
#if METHOD == 0
    lock.l_type = F_UNLCK;
    return fcntl(file, F_SETLKW, &lock) == 0;
#elif METHOD == 1
    return flock(file, LOCK_UN) == 0;
#elif METHOD == 2
    lock.unlock();
    return true;
#endif
  }
  int file;
#if METHOD == 0
  struct flock lock;
#elif METHOD == 2
  boost::interprocess::file_lock lock;
#endif
};

int main(int argc, char **argv)
{
  int repeats = 100;
  double interval = 0.1;
  char message[256];
  sprintf(message, "testing 123\n");

  if (argc >= 2)
    repeats = atoi(argv[1]);
  if (argc >= 3)
    interval = atof(argv[2]);
  if (argc >= 4)
  {
    sprintf(message, "%s\n", argv[3]);
  }
  FILE *f = fopen("a.txt", "a");
  if (f == NULL)
  {
    cout << "can't open" << endl;
    return 1;
  }
#if METHOD == 2
  FileLock lock("a.txt");
#else
  FileLock lock(fileno(f));
#endif
  for (int i = 0; i < repeats; ++i)
  {
    if (!lock.Lock())
     cout << "error locking " << strerror(errno) <<  "\n";

    // file in append mode will automatically write to end, but does it work when there are multiple writers?
    fseek(f, 0, SEEK_END);
    fwrite(message, 1, strlen(message), f);

    if (!lock.Unlock())
      cout << "error unlocking\n";
    usleep(interval * 1000000);
  }
  fclose(f);
  return 0;
}

CIFS字节范围锁定是否可以在Windows作为服务器的多个Linux客户端节点上运行？

0 个答案: