On 06/15/2017 02:03 PM, John Ferlan wrote:
On 06/15/2017 04:53 AM, Michal Privoznik wrote:
> On 06/14/2017 09:50 PM, John Ferlan wrote:
>>
>>
>> On 06/12/2017 11:57 AM, Michal Privoznik wrote:
>>>
https://bugzilla.redhat.com/show_bug.cgi?id=1431112
>>>
>>> After 290a00e41d we know how to deal with file mount points.
>>> However, when cleaning up the temporary location for preserved
>>> mount points we are still calling rmdir(). This won't fly for
>>> files. We need to call unlink(). Now, since we don't really care
>>> if the cleanup succeeded or not (it's the best effort anyway), we
>>> can call both rmdir() and unlink() without need for
>>> differentiation between files and directories.
>>>
>>> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
>>> ---
>>> src/qemu/qemu_domain.c | 5 ++++-
>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>
>> But why call both?
>
> I don't think you can call unlink() over a directory, can you? And sure,
> I could call stat() just to find out if it's a dir or a file and call
> just one of the pair. Or I can call both and ignore any errors. The
> result is the same, isn't it?
>
> Michal
>
From the unlink(3p) man page:
"The path argument shall not name a directory unless the process has
appropriate privileges and the implementation supports using unlink() on
directories."
That's weird. I don't see that in my man page. What I see though is the
following errno code:
EISDIR pathname refers to a directory. (This is the non-POSIX value
returned by Linux since 2.1.132.)
The "non-POSIX" bothers me there. But I agree that whole namespaces are
Linux specific, so it doesn't bother me there that much.
Then a google search on using unlink vs. rmdir uncovers more refs. I
suppose one could also do the "if file, then unlink else rmdir.
Well, to determine if a path is a file or a dir I'd need to call stat()
which can fail. I'm not a big fan of overcomplicating simple code.
Just seems "odd" to see both and leaves one wondering why.
Well, there's a comment that says why.
Michal