/*
 * DF-2550 probe: does VOP_GETATTR fail on a FIFO fd (fchown path)?
 * hammer2/ufs FIFO vnodes normally override getattr, so this likely
 * returns 0 (no failure) -- but verify empirically.
 */
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>

int main(int argc, char **argv) {
    const char *path = argc > 1 ? argv[1] : "ftest";
    unlink(path);
    if (mkfifo(path, 0644) != 0) { perror("mkfifo"); return 2; }
    /* FIFO needs a writer to open O_RDWR; open O_NONBLOCK|O_RDONLY then write-end */
    int fd = open(path, O_RDWR);
    if (fd < 0) { perror("open"); return 2; }
    struct stat st;
    if (fstat(fd, &st) != 0) { printf("fstat errno=%d (%s)\n", errno, strerror(errno)); }
    printf("[probe] fifo fd=%d fstat rc=0 mode=0%o type=%d\n", fd, st.st_mode, (st.st_mode&S_IFMT));
    int rc = fchown(fd, -1, -1);
    printf("[probe] fchown(fd) rc=%d errno=%d (%s)\n", rc, errno, rc? strerror(errno):"ok");
    return 0;
}