Bug 203269

Setup samba server and mount it in local with vers=1.0. Use the reproducer to test if open file succesffully after unlink. The process blocked in wait_for_free_credits and never return.

[<0>] wait_for_free_credits+0x258/0x460 [cifs]
[<0>] SendReceive+0xcd/0x360 [cifs]
[<0>] CIFSPOSIXCreate+0x1bf/0x440 [cifs]
[<0>] cifs_posix_open+0x1ee/0x300 [cifs]
[<0>] cifs_do_create+0x447/0x710 [cifs]
[<0>] cifs_atomic_open+0x1ab/0x530 [cifs]
[<0>] path_openat+0xd54/0x1670
[<0>] do_filp_open+0x93/0x100
[<0>] do_sys_open+0x186/0x220
[<0>] do_syscall_64+0x55/0x1a0
[<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[<0>] 0xffffffffffffffff

reproducer.c:
#define _GNU_SOURCE            
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/file.h>
#include <errno.h>
void test()
{
    int fd;
    int ret;

    fd = open("./testfile",O_RDWR|O_CREAT,0644);
    printf("errno=%d\n",errno);
    if (fd < 0)
    {
        perror("open failed");
        exit(1);
    }
    ret = unlink("./testfile");
    if (ret < 0)
    {
        perror("unlink failed");
        exit(1);
    }
}
int main(int argc, char **argv)
{
    int index=50;
    while(index)
    {
        index--;
        printf("loop %d\n",index);
        test();
    }
    return 0;
}