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

[supriya kannery]

Stefan Hajnoczi wrote:
> On Fri, Nov 11, 2011 at 6:48 AM, Supriya Kannery
> <address@hidden> 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
>
>