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

[John Snow <jsnow@redhat.com>]

ping

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>
>