Re: [Qemu-devel] [PATCH v2 1/4] qapi: Convert getfd and closefd

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri,  8 Jun 2012 11:42:56 -0400
Corey Bryant <coreyb@linux.vnet.ibm.com> wrote:

> v2:
>  - Convert getfd and closefd to QAPI (lcapitulino@redhat.com)
>  - Remove changes that returned fd from getfd (lcapitulino@redhat.com)
>  - Wrap hmp_* functions around qmp_* functions (kwolf@redhat.com)
>  - Move hmp_* functions to hmp.c (lcapitulino@redhat.com)
>  - Drop .user_print lines (lcapitulino@redhat.com)
>  - Use 'cmd' instead of 'cmd_new' for HMP (lcapitulino@redhat.com)
>  - Change QMP command existance back to 0.14 (lcapitulino@redhat.com)
> 
> Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
> ---
>  hmp-commands.hx  |    6 ++----
>  hmp.c            |   18 ++++++++++++++++++
>  hmp.h            |    2 ++
>  monitor.c        |   34 ++++++++++++++++------------------
>  qapi-schema.json |   29 +++++++++++++++++++++++++++++
>  qmp-commands.hx  |    6 ++----
>  6 files changed, 69 insertions(+), 26 deletions(-)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index f5d9d91..eea8b32 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1236,8 +1236,7 @@ ETEXI
>          .args_type  = "fdname:s",
>          .params     = "getfd name",
>          .help       = "receive a file descriptor via SCM rights and assign it a name",
> -        .user_print = monitor_user_noop,
> -        .mhandler.cmd_new = do_getfd,
> +        .mhandler.cmd = hmp_getfd,
>      },
>  
>  STEXI
> @@ -1253,8 +1252,7 @@ ETEXI
>          .args_type  = "fdname:s",
>          .params     = "closefd name",
>          .help       = "close a file descriptor previously passed via SCM rights",
> -        .user_print = monitor_user_noop,
> -        .mhandler.cmd_new = do_closefd,
> +        .mhandler.cmd = hmp_closefd,
>      },
>  
>  STEXI
> diff --git a/hmp.c b/hmp.c
> index 2ce8cb9..6241856 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -999,3 +999,21 @@ void hmp_netdev_del(Monitor *mon, const QDict *qdict)
>      qmp_netdev_del(id, &err);
>      hmp_handle_error(mon, &err);
>  }
> +
> +void hmp_getfd(Monitor *mon, const QDict *qdict)
> +{
> +    const char *fdname = qdict_get_str(qdict, "fdname");
> +    Error *errp = NULL;
> +
> +    qmp_getfd(fdname, &errp);
> +    hmp_handle_error(mon, &errp);
> +}
> +
> +void hmp_closefd(Monitor *mon, const QDict *qdict)
> +{
> +    const char *fdname = qdict_get_str(qdict, "fdname");
> +    Error *errp = NULL;
> +
> +    qmp_closefd(fdname, &errp);
> +    hmp_handle_error(mon, &errp);
> +}
> diff --git a/hmp.h b/hmp.h
> index 79d138d..8d2b0d7 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -64,5 +64,7 @@ void hmp_device_del(Monitor *mon, const QDict *qdict);
>  void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict);
>  void hmp_netdev_add(Monitor *mon, const QDict *qdict);
>  void hmp_netdev_del(Monitor *mon, const QDict *qdict);
> +void hmp_getfd(Monitor *mon, const QDict *qdict);
> +void hmp_closefd(Monitor *mon, const QDict *qdict);
>  
>  #endif
> diff --git a/monitor.c b/monitor.c
> index a3bc2c7..4c53cb6 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -2182,48 +2182,46 @@ static void do_inject_mce(Monitor *mon, const QDict *qdict)
>  }
>  #endif
>  
> -static int do_getfd(Monitor *mon, const QDict *qdict, QObject **ret_data)
> +void qmp_getfd(const char *fdname, Error **errp)
>  {
> -    const char *fdname = qdict_get_str(qdict, "fdname");
>      mon_fd_t *monfd;
>      int fd;
>  
> -    fd = qemu_chr_fe_get_msgfd(mon->chr);
> +    fd = qemu_chr_fe_get_msgfd(cur_mon->chr);
>      if (fd == -1) {
> -        qerror_report(QERR_FD_NOT_SUPPLIED);
> -        return -1;
> +        error_set(errp, QERR_FD_NOT_SUPPLIED);
> +        return;
>      }
>  
>      if (qemu_isdigit(fdname[0])) {
> -        qerror_report(QERR_INVALID_PARAMETER_VALUE, "fdname",
> -                      "a name not starting with a digit");
> -        return -1;
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "fdname",
> +                  "a name not starting with a digit");
> +        return;
>      }
>  
> -    QLIST_FOREACH(monfd, &mon->fds, next) {
> +    QLIST_FOREACH(monfd, &cur_mon->fds, next) {
>          if (strcmp(monfd->name, fdname) != 0) {
>              continue;
>          }
>  
>          close(monfd->fd);
>          monfd->fd = fd;
> -        return 0;
> +        return;
>      }
>  
>      monfd = g_malloc0(sizeof(mon_fd_t));
>      monfd->name = g_strdup(fdname);
>      monfd->fd = fd;
>  
> -    QLIST_INSERT_HEAD(&mon->fds, monfd, next);
> -    return 0;
> +    QLIST_INSERT_HEAD(&cur_mon->fds, monfd, next);
> +    return;

You have a few of this kind of gratuitous return, please drop 'em.

>  }
>  
> -static int do_closefd(Monitor *mon, const QDict *qdict, QObject **ret_data)
> +void qmp_closefd(const char *fdname, Error **errp)
>  {
> -    const char *fdname = qdict_get_str(qdict, "fdname");
>      mon_fd_t *monfd;
>  
> -    QLIST_FOREACH(monfd, &mon->fds, next) {
> +    QLIST_FOREACH(monfd, &cur_mon->fds, next) {
>          if (strcmp(monfd->name, fdname) != 0) {
>              continue;
>          }
> @@ -2232,11 +2230,11 @@ static int do_closefd(Monitor *mon, const QDict *qdict, QObject **ret_data)
>          close(monfd->fd);
>          g_free(monfd->name);
>          g_free(monfd);
> -        return 0;
> +        return;
>      }
>  
> -    qerror_report(QERR_FD_NOT_FOUND, fdname);
> -    return -1;
> +    error_set(errp, QERR_FD_NOT_FOUND, fdname);
> +    return;
>  }
>  
>  static void do_loadvm(Monitor *mon, const QDict *qdict)
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 3b6e346..6be1d90 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1862,3 +1862,32 @@
>  # Since: 0.14.0
>  ##
>  { 'command': 'netdev_del', 'data': {'id': 'str'} }
> +
> +##
> +# @getfd:
> +#
> +# Receive a file descriptor via SCM rights and assign it a name
> +#
> +# @fdname: file descriptor name
> +#
> +# Returns: Nothing on success
> +#          If file descriptor was not received, FdNotSupplied
> +#          If @fdname is not valid, InvalidParameterType

Please, add a note explaining that getfd automatically closes fds if
fdname matches an existing name.

Otherwise this conversion looks very good to me.

> +#
> +# Since: 0.14.0
> +##
> +{ 'command': 'getfd', 'data': {'fdname': 'str'} }
> +
> +##
> +# @closefd:
> +#
> +# Close a file descriptor previously passed via SCM rights
> +#
> +# @fdname: file descriptor name
> +#
> +# Returns: Nothing on success
> +#          If @fdname is not found, FdNotFound
> +#
> +# Since: 0.14.0
> +##
> +{ 'command': 'closefd', 'data': {'fdname': 'str'} }
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 2e1a38e..f8c0f68 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -873,8 +873,7 @@ EQMP
>          .args_type  = "fdname:s",
>          .params     = "getfd name",
>          .help       = "receive a file descriptor via SCM rights and assign it a name",
> -        .user_print = monitor_user_noop,
> -        .mhandler.cmd_new = do_getfd,
> +        .mhandler.cmd_new = qmp_marshal_input_getfd,
>      },
>  
>  SQMP
> @@ -899,8 +898,7 @@ EQMP
>          .args_type  = "fdname:s",
>          .params     = "closefd name",
>          .help       = "close a file descriptor previously passed via SCM rights",
> -        .user_print = monitor_user_noop,
> -        .mhandler.cmd_new = do_closefd,
> +        .mhandler.cmd_new = qmp_marshal_input_closefd,
>      },
>  
>  SQMP