Re: qemu iotest 161 and make check

[Christian Borntraeger]

Am 31.03.22 um 09:44 schrieb Christian Borntraeger:
> Am 21.02.22 um 11:27 schrieb Christian Borntraeger:
> > Am 10.02.22 um 18:44 schrieb Vladimir Sementsov-Ogievskiy:
> > > 10.02.2022 20:13, Thomas Huth wrote:
> > > > On 10/02/2022 15.51, Christian Borntraeger wrote:
> > > > > Am 10.02.22 um 15:47 schrieb Vladimir Sementsov-Ogievskiy:
> > > > > > 10.02.2022 10:57, Christian Borntraeger wrote:
> > > > > > > Hello,
> > > > > > >
> > > > > > > I do see spurious failures of 161 in our CI, but only when I use
> > > > > > > make check with parallelism (-j).
> > > > > > > I have not yet figured out which other testcase could interfere
> > > > > > >
> > > > > > > @@ -34,6 +34,8 @@
> > > > > > >   *** Commit and then change an option on the backing file
> > > > > > >
> > > > > > >   Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=1048576
> > > > > > > +qemu-img: TEST_DIR/t.IMGFMT.base: Failed to get "write" lock
>
> FWIW, qemu_lock_fd_test returns -11 (EAGAIN)
> and raw_check_lock_bytes spits this error.


And its coming from here (ret is 0)

int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive)
{
    int ret;
    struct flock fl = {
        .l_whence = SEEK_SET,
        .l_start  = start,
        .l_len    = len,
        .l_type   = exclusive ? F_WRLCK : F_RDLCK,
    };
    qemu_probe_lock_ops();
    ret = fcntl(fd, fcntl_op_getlk, &fl);
    if (ret == -1) {
        return -errno;
    } else {
----->        return fl.l_type == F_UNLCK ? 0 : -EAGAIN;
    }
}

> Is this just some overload situation that we do not recover because we do not 
> handle EAGAIN any special.