Re: [Qemu-devel] [PATCH v4] file-posix: specify expected filetypes

[John Snow <jsnow@redhat.com>]

On 03/19/2018 11:29 AM, Kevin Wolf wrote:
> Am 13.03.2018 um 18:20 hat John Snow geschrieben:
>>
>>
>> On 01/19/2018 06:03 PM, Eric Blake wrote:
>>> On 01/19/2018 04:47 PM, John Snow wrote:
>>>> Adjust each caller of raw_open_common to specify if they are expecting
>>>> host and character devices or not. Tighten expectations of file types upon
>>>> open in the common code and refuse types that are not expected.
>>>>
>>>> This has two effects:
>>>>
>>>> (1) Character and block devices are now considered deprecated for the
>>>>     'file' driver, which expects only S_IFREG, and
>>>> (2) no file-posix driver (file, host_cdrom, or host_device) can open
>>>>     directories now.
>>>>
>>>> I don't think there's a legitimate reason to open directories as if
>>>> they were files. This prevents QEMU from opening and attempting to probe
>>>> a directory inode, which can break in exciting ways. One of those ways
>>>> is lseek on ext4/xfs, which will return 0x7fffffffffffffff as the file
>>>> size instead of EISDIR. This can coax QEMU into responding with a
>>>> confusing "file too big" instead of "Hey, that's not a file".
>>>>
>>>> See: https://bugs.launchpad.net/qemu/+bug/1739304/
>>>> Signed-off-by: John Snow <jsnow@redhat.com>
>>>> ---
>>>
>>> Reviewed-by: Eric Blake <eblake@redhat.com>
>>
>> Whoops, I let this one rot. It could still be considered a bugfix for
>> next week.
> 
> Yes, we should take this as a bugfix. Needs a rebase, though.
> 
> Kevin
> 

You got it.

--js