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Subject: Re: [PATCH] xfs: add selinux labels to whiteout inodes
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From:   Eric Sandeen <sandeen@redhat.com>
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I had mentioned this problem in passing to dchinner, and came away with
a vague sense that I might be Doing It Wrong. So I should have labeled
the patch RFC, I suppose.

An easy way to demonstrate the selinux label result is with this test
program, as provided by the bug reporter.  ls -lZ will then show you
the resulting labels on each file.

#define _GNU_SOURCE
#include <sys/mount.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdio.h>
#include <unistd.h>
int main(int argc, char **argv) {
	int rc, fd, dirfd;
	rc = mkdir("upper", 0700);
	if ((rc != 0) && (errno != EEXIST)) {
		perror("mkdir");
		return rc;
	}
	rc = unlink("upper/0");
	if ((rc != 0) && (errno != ENOENT)) {
		perror("unlink");
		return rc;
	}
	rc = unlink("upper/empty");
	if ((rc != 0) && (errno != ENOENT)) {
		perror("unlink");
		return rc;
	}
	dirfd = open("upper", O_PATH);
	if (dirfd == -1) {
		perror("open");
		return dirfd;
	}
	fd = creat("upper/empty", 0600);
	if (fd == -1) {
		perror("creat");
		return fd;
	}
	close(fd);
	rc = renameat2(dirfd, "empty", dirfd, "0", RENAME_WHITEOUT);
	if (rc == -1) {
		perror("renameat2");
		return rc;
	}
	close(dirfd);
	return 0;
}