On Thu, 2 Jun 2016 15:00:26 -0600
Eric Blake <ebl...@redhat.com> wrote:
> On 06/02/2016 02:52 AM, Greg Kurz wrote:
> > This patch changes the 9p code to use readdir() again instead of
> > readdir_r(), which is deprecated in glibc 2.24.
> >
> > All the locking was put in place by a previous patch.
> >
> > Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com>
> > ---
>
>
> > +++ b/hw/9pfs/codir.c
> > @@ -17,8 +17,7 @@
> > #include "qemu/coroutine.h"
> > #include "coth.h"
> >
> > -int v9fs_co_readdir_r(V9fsPDU *pdu, V9fsFidState *fidp, struct dirent
> > *dent,
> > - struct dirent **result)
> > +int v9fs_co_readdir(V9fsPDU *pdu, V9fsFidState *fidp, struct dirent **dent)
> > {
> > int err;
> > V9fsState *s = pdu->s;
> > @@ -28,11 +27,14 @@ int v9fs_co_readdir_r(V9fsPDU *pdu, V9fsFidState *fidp,
> > struct dirent *dent,
> > }
> > v9fs_co_run_in_worker(
> > {
> > - errno = 0;
> > - err = s->ops->readdir_r(&s->ctx, &fidp->fs, dent, result);
> > - if (!*result && errno) {
> > + struct dirent *entry;
> > + int old_errno = errno;
> > +
> > + entry = s->ops->readdir(&s->ctx, &fidp->fs);
> > + if (!entry && errno != old_errno) {
> > err = -errno;
>
> Not safe. The only safe way to check errno after readdir() is to assign
> it to 0 before readdir().
>
Yeah, you're right, errno could already be set to one of the values
returned by readdir() in case of error...
> > } else {
> > + *dent = entry;
> > err = 0;
> > }
> > });
>
>
