On 08/30/2012 06:15 PM, Eric Blake wrote:
> On 08/30/2012 11:47 AM, Jeff Cody wrote:
>> This is derived from the Supriya Kannery's reopen patches.
>>
>> This contains the raw-posix driver changes for the bdrv_reopen_*
>> functions. All changes are staged into a temporary scratch buffer
>> during the prepare() stage, and copied over to the live structure
>> during commit(). Upon abort(), all changes are abandoned, and the
>> live structures are unmodified.
>>
>> The _prepare() will create an extra fd - either by means of a dup,
>> if possible, or opening a new fd if not (for instance, access
>> control changes). Upon _commit(), the original fd is closed and
>> the new fd is used. Upon _abort(), the duplicate/new fd is closed.
>>
>
>> + if ((raw_s->open_flags & ~fcntl_flags) == (s->open_flags &
>> ~fcntl_flags)) {
>> + /* dup the original fd */
>> + /* TODO: use qemu fcntl wrapper */
>> + raw_s->fd = fcntl(s->fd, F_DUPFD_CLOEXEC, 0);
>
> I assume this TODO has to be fixed to allow compilation on systems that
> lack F_DUPFD_CLOEXEC.
Yes, either that or add the logic here.
>
>> + if (raw_s->fd == -1) {
>> + ret = -1;
>> + goto error;
>> + }
>> + ret = fcntl_setfl(raw_s->fd, raw_s->open_flags);
>> + } else {
>> + raw_s->fd = qemu_open(state->bs->filename, raw_s->open_flags, 0644);
>
> Is raw_s->open_flags every going to contain O_CREAT, or is the 0644 mode
> argument spurious?
>
Thanks, you are right, it is spurious. The raw_s->open_flags are
explicitly set via raw_parse_flags(), so we know it will never contain
O_CREAT.
