Re: [Qemu-devel] [PATCH 11/18] nbd: ask and print error information from qemu-sockets

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 05 Oct 2012 08:27:25 +0200
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Il 04/10/2012 22:08, Luiz Capitulino ha scritto:
> > On Wed,  3 Oct 2012 16:36:58 +0200
> > Paolo Bonzini <pbonzini@redhat.com> wrote:
> > 
> >> Before:
> >>
> >>     $ qemu-system-x86_64 nbd:localhost:12345
> >>     inet_connect_opts: connect(ipv4,yakj.usersys.redhat.com,127.0.0.1,12345): Connection refused
> >>     qemu-system-x86_64: could not open disk image nbd:localhost:12345: Connection refused
> >>
> >> After:
> >>
> >>     $ x86_64-softmmu/qemu-system-x86_64 nbd:localhost:12345
> >>     qemu-system-x86_64: Failed to connect to socket: Connection refused
> >>     qemu-system-x86_64: could not open disk image nbd:localhost:12345: Connection refused
> >>
> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> >> ---
> >>  nbd.c | 39 +++++++++++++++++++++++++++++++--------
> >>  1 file modificato, 31 inserzioni(+), 8 rimozioni(-)
> >>
> >> diff --git a/nbd.c b/nbd.c
> >> index f61a288..cec5a94 100644
> >> --- a/nbd.c
> >> +++ b/nbd.c
> >> @@ -208,7 +208,14 @@ int tcp_socket_outgoing(const char *address, uint16_t port)
> >>  
> >>  int tcp_socket_outgoing_spec(const char *address_and_port)
> >>  {
> >> -    return inet_connect(address_and_port, NULL);
> >> +    Error *local_err = NULL;
> >> +    int fd = inet_connect(address_and_port, &local_err);
> >> +
> >> +    if (local_err != NULL) {
> >> +        qerror_report_err(local_err);
> >> +        error_free(local_err);
> > 
> > Can't you propagate errp instead of using qerror_report_err()? This function
> > should only be used when the caller expects QError semantics.
> 
> No, I cannot.  These functions are used only for a) qemu-nbd, for which
> qerror_report_err() is ok; b) the NBD driver's bdrv_open, which is not
> able to propagate errors yet.
> 
> When error propagation is added to bdrv_open they can just disappear,
> replaced by direct calls to functions in qemu-sockets.c.

Ok. I've started working on adding error propagation to bdrv_open(), should
have a series soon.