Re: Permission denied when chainbuilding packages with mock

[Julian Sikorski <belegdol@gmail.com>]

Am 15.11.21 um 04:25 schrieb Steve French:
> The patch is in Linus's tree, so you should be able to try it with the
> weekly kernel updates for various distros which have download sites
> for more current kernel packages (Ubuntu, Fedora etc.) or build kernel
> yourself if you prefer.
> 
> To get it into stable we will need to send a followup email as
> described in their process guide below:
> 
> "send an email to stable@vger.kernel.org containing the subject of the
> patch, the commit ID, why you think it should be applied"
> 
> but some of the distros will apply it automatically (it is still
> helpful to send the email to stable as a reminder)
> 
Thank you. I found the patch in the Linus' tree yesterday and I saw you 
have just sent the email to stable. So it looks like we are all set. 
Thank you again for fixing this so quickly.

Best regards,
Julian

> On Sat, Nov 13, 2021 at 9:37 AM Julian Sikorski <belegdol@gmail.com> wrote:
>>
>> Am 10.11.21 um 12:23 schrieb Julian Sikorski:
>>> W dniu 10.11.2021 o 08:56, Steve French pisze:
>>>> Fix for the kernel client attached
>>>>
>>>>
>>>> On Tue, Nov 9, 2021 at 6:54 PM Jeremy Allison <jra@samba.org> wrote:
>>>>>
>>>>> On Tue, Nov 09, 2021 at 10:26:59AM +0100, Julian Sikorski wrote:
>>>>>> Am 09.11.21 um 09:10 schrieb Steve French:
>>>>>>> Yes - here is a trivial reproducer (excuse the ugly sample
>>>>>>> cut-n-paste)
>>>>>>>
>>>>>>> #include <stdio.h>
>>>>>>> #include <stdlib.h>
>>>>>>> #include <unistd.h>
>>>>>>> #include <string.h>
>>>>>>> #include <fcntl.h>
>>>>>>> #include <sys/types.h>
>>>>>>> #include <sys/stat.h>
>>>>>>>
>>>>>>> int main(int argc, char *argv[]) {
>>>>>>> char *str = "Text to be added";
>>>>>>> int fd, ret, fsyncrc, fsyncr_rc, openrc, closerc, close2rc;
>>>>>>>
>>>>>>> fd = creat("test.txt", S_IWUSR | S_IRUSR);
>>>>>>> if (fd < 0) {
>>>>>>> perror("creat()");
>>>>>>> exit(1);
>>>>>>> }
>>>>>>> ret = write(fd, str, strlen(str));
>>>>>>> if (ret < 0) {
>>>>>>> perror("write()");
>>>>>>> exit(1);
>>>>>>> }
>>>>>>> openrc = open("test.txt", O_RDONLY);
>>>>>>>           if (openrc < 0) {
>>>>>>>                   perror("creat()");
>>>>>>>                   exit(1);
>>>>>>>           }
>>>>>>> fsyncr_rc = fsync(openrc);
>>>>>>> if (fsyncr_rc < 0)
>>>>>>> perror("fsync()");
>>>>>>> fsyncrc = fsync(fd);
>>>>>>> closerc = close(fd);
>>>>>>> close2rc = close(openrc);
>>>>>>> printf("read fsync rc=%d, write fsync rc=%d, close rc=%d, RO close
>>>>>>> rc=%d\n", fsyncr_rc, fsyncrc, closerc, close2rc);
>>>>>>> }
>>>>>>>
>>>>>>
>>>>>> I can confirm this fails on my machine without nostrictsync:
>>>>>>
>>>>>> $ ./test
>>>>>>
>>>>>> fsync(): Permission denied
>>>>>>
>>>>>> read fsync rc=-1, write fsync rc=0, close rc=0, RO close rc=0
>>>>>>
>>>>>> and works with nostrictsync:
>>>>>>
>>>>>> $ ./test
>>>>>>
>>>>>> read fsync rc=0, write fsync rc=0, close rc=0, RO close rc=0
>>>>>>
>>>>>> So is the bug in the Linux kernel?
>>>>>
>>>>> Yes, it's in the kernel cifsfs module which is forwarding an
>>>>> SMB_FLUSH request
>>>>> (which the spec says must fail on a non-writable handle) to
>>>>> a handle opened as non-writable. Steve hopefully will fix :-).
>>>>
>>>>
>>>>
>>> Thank you. I can confirm that 5.15.1 kernel with this patch applied [1]
>>> works both with the test case you provided earlier as well as with mock
>>> chainbuilds without the need for the nostrictsync mount option. Fedora
>>> kernel-5.14.16-301.fc35.x86_64 was failing without it.
>>>
>>> Tested-by: Julian Sikorski <belegdol@gmail.com>
>>>
>>> Best regards,
>>> Julian
>>>
>>> [1] https://gitlab.com/belegdol/kernel-ark/-/commits/fedora-5.15-cifs-fix/
>>
>> Hi,
>>
>> may I ask what the usual process of getting the patch into the Linus's
>> tree and to the stable branches is? If it takes longer, I am going to go
>> back to nostrictsync for now.
>>
>> Best regards,
>> Julian
> 
> 
>