Yeah, that's busted, and I see the bug (we're calculating the size
incorrectly); I'll fix that when I fix FIONREAD -- with my apologies...
- Bryan
On Wed, Dec 10, 2014 at 12:37 PM, Youzhong Yang <[email protected]> wrote:
> Hi Bryan,
>
> I saw the bug in the function inotify_ioctl() and tried to fix it. Now
> with my new image ioctl(FIONREAD) returns state->ins_size as the bytes
> available to be read.
>
> [root@batfs5901 ~]# /var/tmp/inotify
> ioctl = 0, errno = 0, bufsize = 64
> got 48 bytes
> -> New file yyang created
> -> yyang ATTRIB
>
> this state->ins_size seems larger than the number of bytes read by read()
> call, i.e. state->ins_size does not tell the exact number of bytes
> available for read.
>
> This can be a problem when the program expects to read that many bytes. I
> just confirmed it causes issue in Samba.
>
> Thanks,
>
> -- Youzhong
>
>
> On Wed, Dec 10, 2014 at 1:05 PM, Bryan Cantrill <[email protected]>
> wrote:
>
>>
>> The touch differences can be explained by the touch(1) that you're using:
>> in the global zone, you're using /usr/bin/touch, but in the non-global, I
>> imagine that you're using /opt/local/bin/touch. These two implementations
>> differ, so not a huge surprise that their implementation details differ.
>>
>> As for FIONREAD: indeed, that seems screwed up -- it seems to be
>> returning the number of bytes instead of storing in in the specified
>> argument. I'll get that fixed today...
>>
>> - Bryan
>>
>>
>>
>> On Wed, Dec 10, 2014 at 8:00 AM, Youzhong Yang via smartos-discuss <
>> [email protected]> wrote:
>>
>>> Hello again,
>>>
>>> I downloaded smartos latest image (joyent_20141127T173954Z) and tested
>>> inotify using it.
>>>
>>> Two issues were observed:
>>>
>>> 1. ioctl(fd, FIONREAD, ...) does not work as expected. It does not
>>> return the number of bytes that are available to be read on an inotify
>>> instance.
>>>
>>> 2. In an OS zone, touching a file always generates an IN_CREATE event,
>>> even though the file already exists. This only happens in an OS zone, not
>>> in global zone.
>>>
>>> Attached is the test program I used for testing. Just compile and run
>>> it, then in another terminal window, 'touch /tmp/file' twice. Please look
>>> at the details at the end of this e-mail.
>>>
>>> Thanks,
>>>
>>> -Youzhong
>>>
>>> --- In global zone ---
>>> [root@batfs5999 /var/tmp]# ./inotify
>>> ioctl = 64, errno = 0, bufsize = 0
>>> got 48 bytes
>>> :: mask 256
>>> -> New file file created
>>> :: mask 4
>>> -> file ATTRIB
>>> ioctl = 32, errno = 0, bufsize = 0
>>> got 24 bytes
>>> :: mask 4
>>> -> file ATTRIB
>>>
>>> --- In OS zone ---
>>> [root@batfs5999-cifs0 /var/tmp]# ./inotify
>>> ioctl = 64, errno = 0, bufsize = 0
>>> got 48 bytes
>>> :: mask 256
>>> -> New file file created
>>> :: mask 4
>>> -> file ATTRIB
>>> ioctl = 64, errno = 0, bufsize = 0
>>> got 48 bytes
>>> :: mask 256
>>> -> New file file created
>>> :: mask 4
>>> -> file ATTRIB
>>>
>>> --- On Linux ---
>>> % ./inotify
>>> ioctl = 0, errno = 0, bufsize = 32
>>> got 32 bytes
>>> :: mask 256
>>> -> New file file created
>>> ioctl = 0, errno = 0, bufsize = 32
>>> got 32 bytes
>>> :: mask 4
>>> -> file ATTRIB
>>> ioctl = 0, errno = 0, bufsize = 32
>>> got 32 bytes
>>> :: mask 4
>>> -> file ATTRIB
>>>
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