Re: [Qemu-devel] [PATCH 3/3] qemu-sockets: Add error to non-blocking connect handler

[Paolo Bonzini <pbonzini@redhat.com>]

Il 08/10/2014 14:11, minyard@acm.org ha scritto:
> From: Corey Minyard <cminyard@mvista.com>
> 
> An error value here would be quite handy and more consistent
> with the rest of the code.
> 
> Corey Minyard <cminyard@mvista.com>
> ---
>  include/qemu/sockets.h |  2 +-
>  migration-tcp.c        |  4 ++--
>  migration-unix.c       |  4 ++--
>  qemu-char.c            |  6 +++---
>  util/qemu-sockets.c    | 19 ++++++++++++++-----
>  5 files changed, 22 insertions(+), 13 deletions(-)
> 
> diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
> index fdbb196..f47dae6 100644
> --- a/include/qemu/sockets.h
> +++ b/include/qemu/sockets.h
> @@ -47,7 +47,7 @@ int recv_all(int fd, void *buf, int len1, bool single_read);
>  /* callback function for nonblocking connect
>   * valid fd on success, negative error code on failure
>   */
> -typedef void NonBlockingConnectHandler(int fd, void *opaque);
> +typedef void NonBlockingConnectHandler(int fd, Error *errp, void *opaque);
>  
>  InetSocketAddress *inet_parse(const char *str, Error **errp);
>  int inet_listen_opts(QemuOpts *opts, int port_offset, Error **errp);
> diff --git a/migration-tcp.c b/migration-tcp.c
> index 2e34517..91c9cf3 100644
> --- a/migration-tcp.c
> +++ b/migration-tcp.c
> @@ -33,12 +33,12 @@
>      do { } while (0)
>  #endif
>  
> -static void tcp_wait_for_connect(int fd, void *opaque)
> +static void tcp_wait_for_connect(int fd, Error *err, void *opaque)
>  {
>      MigrationState *s = opaque;
>  
>      if (fd < 0) {
> -        DPRINTF("migrate connect error\n");
> +        DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
>          s->file = NULL;
>          migrate_fd_error(s);
>      } else {
> diff --git a/migration-unix.c b/migration-unix.c
> index 0a5f8a1..1cdadfb 100644
> --- a/migration-unix.c
> +++ b/migration-unix.c
> @@ -33,12 +33,12 @@
>      do { } while (0)
>  #endif
>  
> -static void unix_wait_for_connect(int fd, void *opaque)
> +static void unix_wait_for_connect(int fd, Error *err, void *opaque)
>  {
>      MigrationState *s = opaque;
>  
>      if (fd < 0) {
> -        DPRINTF("migrate connect error\n");
> +        DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
>          s->file = NULL;
>          migrate_fd_error(s);
>      } else {
> diff --git a/qemu-char.c b/qemu-char.c
> index 83ff458..8f3af06 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -3061,14 +3061,14 @@ static void qemu_chr_finish_socket_connection(CharDriverState *chr, int fd)
>      }
>  }
>  
> -static void qemu_chr_socket_connected(int fd, void *opaque)
> +static void qemu_chr_socket_connected(int fd, Error *err, void *opaque)
>  {
>      CharDriverState *chr = opaque;
>      TCPCharDriver *s = chr->opaque;
>  
>      if (fd < 0) {
> -        check_report_connect_error(chr, "Unable to connect to socket %s",
> -                                   chr->label);
> +        check_report_connect_error(chr, "Unable to connect to socket %s: %s",
> +                                   chr->label, error_get_pretty(err));
>          return;
>      }
>  
> diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
> index 1eef590..e6a9644 100644
> --- a/util/qemu-sockets.c
> +++ b/util/qemu-sockets.c
> @@ -234,6 +234,7 @@ static void wait_for_connect(void *opaque)
>      int val = 0, rc = 0;
>      socklen_t valsize = sizeof(val);
>      bool in_progress;
> +    Error *err = NULL;
>  
>      qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
>  
> @@ -248,6 +249,7 @@ static void wait_for_connect(void *opaque)
>  
>      /* connect error */
>      if (rc < 0) {
> +        error_setg_errno(&err, errno, "Error connecting to socket");
>          closesocket(s->fd);
>          s->fd = rc;
>      }

This is missing above this hunk:

diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index e6a9644..a76bb3c 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -245,6 +245,7 @@ static void wait_for_connect(void *opaque)
     /* update rc to contain error */
     if (!rc && val) {
         rc = -1;
+        errno = val;
     }

     /* connect error */

> @@ -257,9 +259,14 @@ static void wait_for_connect(void *opaque)
>          while (s->current_addr->ai_next != NULL && s->fd < 0) {
>              s->current_addr = s->current_addr->ai_next;
>              s->fd = inet_connect_addr(s->current_addr, &in_progress, s, NULL);
> +            if (s->fd < 0) {
> +                error_free(err);
> +                err = NULL;
> +                error_setg_errno(&err, errno, "Unable to start socket connect");
> +            }
>              /* connect in progress */
>              if (in_progress) {
> -                return;
> +                goto out;
>              }
>          }
>  
> @@ -267,9 +274,11 @@ static void wait_for_connect(void *opaque)
>      }
>  
>      if (s->callback) {
> -        s->callback(s->fd, s->opaque);
> +        s->callback(s->fd, err, s->opaque);
>      }
>      g_free(s);
> +out:
> +    error_free(err);
>  }
>  
>  static int inet_connect_addr(struct addrinfo *addr, bool *in_progress,
> @@ -401,7 +410,7 @@ int inet_connect_opts(QemuOpts *opts, Error **errp,
>          return sock;
>      } else {
>          if (callback) {
> -            callback(sock, opaque);
> +            callback(sock, NULL, opaque);
>          }
>      }
>      g_free(connect_state);
> @@ -769,7 +778,7 @@ int unix_connect_opts(QemuOpts *opts, Error **errp,
>      } else if (rc >= 0) {
>          /* non blocking socket immediate success, call callback */
>          if (callback != NULL) {
> -            callback(sock, opaque);
> +            callback(sock, NULL, opaque);
>          }
>      }
>  
> @@ -919,7 +928,7 @@ int socket_connect(SocketAddress *addr, Error **errp,
>          fd = monitor_get_fd(cur_mon, addr->fd->str, errp);
>          if (fd >= 0 && callback) {
>              qemu_set_nonblock(fd);
> -            callback(fd, opaque);
> +            callback(fd, NULL, opaque);
>          }
>          break;
>  
>