On Tue, Nov 22, 2011 at 9:45 AM, supriya kannery <supri...@in.ibm.com> wrote:
> supriya kannery wrote:
>>
>> Stefan Hajnoczi wrote:
>>>
>>> On Fri, Nov 11, 2011 at 6:48 AM, Supriya Kannery
>>> <supri...@linux.vnet.ibm.com> wrote:
>>>
>>>>
>>>> + }
>>>> + if ((flags & BDRV_O_NOCACHE)) {
>>>> + raw_rs->reopen_state.reopen_flags |= O_DIRECT;
>>>> + } else {
>>>> + raw_rs->reopen_state.reopen_flags &= ~O_DIRECT;
>>>> + }
>>>> + ret = fcntl_setfl(raw_rs->reopen_fd,
>>>> raw_rs->reopen_state.reopen_flags);
>>>>
>>>
>>> I wonder if this works on Solaris, FreeBSD, etc?
>>>
>>> Perhaps there needs to be a fallback to the missing "else" case below...
>>>
>>>
>>
>> ok. Will look into whether this will work on Solaris, FreeBSD etc..
>>
>
> This should work for all non-win Oses.
> I have tested only in x86.
>
> #ifndef _WIN32
> /* Sets a specific flag */
> int fcntl_setfl(int fd, int flag)
> {
> int flags;
>
> flags = fcntl(fd, F_GETFL);
Are you sure POSIX guarantees that O_DIRECT can be changed with
F_SETFL? I didn't find any statement in the specification. It is
possible that this code compiles but does not actually work on
non-Linux OSes. Did you run tests?
Stefan
