Re: 2.6.xx: NFS: directory motion/cam2 contains a readdir loop

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

Justin,

can you please run the attached test program on the affected directory
on the server, and see if you see duplicates in the d_off colum.  Unless
you have privacy concerns I would also love to see the full output.

#define _GNU_SOURCE

#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/syscall.h>

#define handle_error(msg) \
               do { perror(msg); exit(EXIT_FAILURE); } while (0)

struct linux_dirent64 {
	unsigned long long d_ino;
	long long d_off;
	unsigned short d_reclen;
	unsigned char d_type;
	char d_name[];
};

#define BUF_SIZE 131072

int main(int argc, char *argv[])
{
	int fd, nread;
	char buf[BUF_SIZE];
	struct linux_dirent64 *d;
	int bpos;

	fd = open(argc > 1 ? argv[1] : ".", O_RDONLY | O_DIRECTORY);
	if (fd == -1)
		handle_error("open");

	for (;;) {
		nread = syscall(SYS_getdents64, fd, buf, BUF_SIZE);
		if (nread == -1)
			handle_error("getdents");

		if (nread == 0)
			break;

		printf("--------------- nread=%d ---------------\n", nread);
		printf("i-node#          type  d_reclen  d_off   d_name\n");
		for (bpos = 0; bpos < nread;) {
			d = (struct linux_dirent64 *)(buf + bpos);
			printf("%16lld  ", d->d_ino);
			printf("%4d %10lld  %s\n", d->d_reclen,
			       d->d_off, d->d_name);
			bpos += d->d_reclen;
		}
	}

	exit(EXIT_SUCCESS);
}