Re: [Qemu-devel] [v9 Patch 6/6]Qemu: raw posix implementation of reopen functions

[supriya kannery <supriyak@in.ibm.com>]

Stefan Hajnoczi wrote:
> On Fri, Nov 11, 2011 at 6:48 AM, Supriya Kannery
> <supriyak@linux.vnet.ibm.com> wrote:
>   
>> +static int raw_reopen_prepare(BlockDriverState *bs, BDRVReopenState **prs,
>> +                              int flags)
>> +{
>> +    BDRVRawReopenState *raw_rs = g_malloc0(sizeof(BDRVRawReopenState));
>> +    BDRVRawState *s = bs->opaque;
>> +    int ret = 0;
>> +
>> +    raw_rs->reopen_state.reopen_flags = s->open_flags;
>> +    raw_rs->reopen_state.bs = bs;
>> +    raw_rs->reopen_fd = -1;
>> +    *prs = &(raw_rs->reopen_state);
>> +
>> +    /* Flags that can be set using fcntl */
>> +    int fcntl_flags = BDRV_O_NOCACHE;
>> +
>> +    if ((bs->open_flags & ~fcntl_flags) == (flags & ~fcntl_flags)) {
>> +        raw_rs->reopen_fd = dup(s->fd);
>> +        if (raw_rs->reopen_fd <= 0) {
>> +            return -1;
>>     
>
> return -errno;
>
>   
>> +        }
>> +        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..

>> +    } else {
>> +
>> +        /* TBD: Handle O_DSYNC and other flags. For now return error */
>> +        ret = -1;
>>     
>
> ...and this needs to be implemented.
>
>   

ok

>> +    }
>> +    return ret;
>> +}
>>     
>
> Stefan
>
>