Re: [PATCH v3 09/13] monitor/hmp: move remaining hmp_block* functions to block-hmp-cmds.c

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Maxim Levitsky (mlevitsk@redhat.com) wrote:
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  block/monitor/block-hmp-cmds.c     | 138 +++++++++++++++++++++++++++++
>  include/block/block-hmp-commands.h |   9 ++
>  include/monitor/hmp.h              |   6 --
>  monitor/hmp-cmds.c                 | 137 ----------------------------
>  4 files changed, 147 insertions(+), 143 deletions(-)
> 
> diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
> index df0178d0f9..60d63bfe18 100644
> --- a/block/monitor/block-hmp-cmds.c
> +++ b/block/monitor/block-hmp-cmds.c
> @@ -29,6 +29,7 @@
>  #include "block/block_int.h"
>  #include "block/block-hmp-commands.h"
>  #include "monitor/hmp.h"
> +#include "qemu-io.h"
>  
>  void hmp_drive_add(Monitor *mon, const QDict *qdict)
>  {
> @@ -415,3 +416,140 @@ void hmp_nbd_server_stop(Monitor *mon, const QDict *qdict)
>      qmp_nbd_server_stop(&err);
>      hmp_handle_error(mon, err);
>  }
> +
> +void hmp_block_resize(Monitor *mon, const QDict *qdict)
> +{
> +    const char *device = qdict_get_str(qdict, "device");
> +    int64_t size = qdict_get_int(qdict, "size");
> +    Error *err = NULL;
> +
> +    qmp_block_resize(true, device, false, NULL, size, &err);
> +    hmp_handle_error(mon, err);
> +}
> +
> +void hmp_block_stream(Monitor *mon, const QDict *qdict)
> +{
> +    Error *error = NULL;
> +    const char *device = qdict_get_str(qdict, "device");
> +    const char *base = qdict_get_try_str(qdict, "base");
> +    int64_t speed = qdict_get_try_int(qdict, "speed", 0);
> +
> +    qmp_block_stream(true, device, device, base != NULL, base, false, NULL,
> +                     false, NULL, qdict_haskey(qdict, "speed"), speed, true,
> +                     BLOCKDEV_ON_ERROR_REPORT, false, false, false, false,
> +                     &error);
> +
> +    hmp_handle_error(mon, error);
> +}
> +
> +void hmp_block_passwd(Monitor *mon, const QDict *qdict)
> +{
> +    const char *device = qdict_get_str(qdict, "device");
> +    const char *password = qdict_get_str(qdict, "password");
> +    Error *err = NULL;
> +
> +    qmp_block_passwd(true, device, false, NULL, password, &err);
> +    hmp_handle_error(mon, err);
> +}
> +
> +void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict)
> +{
> +    Error *err = NULL;
> +    char *device = (char *) qdict_get_str(qdict, "device");
> +    BlockIOThrottle throttle = {
> +        .bps = qdict_get_int(qdict, "bps"),
> +        .bps_rd = qdict_get_int(qdict, "bps_rd"),
> +        .bps_wr = qdict_get_int(qdict, "bps_wr"),
> +        .iops = qdict_get_int(qdict, "iops"),
> +        .iops_rd = qdict_get_int(qdict, "iops_rd"),
> +        .iops_wr = qdict_get_int(qdict, "iops_wr"),
> +    };
> +
> +    /* qmp_block_set_io_throttle has separate parameters for the
> +     * (deprecated) block device name and the qdev ID but the HMP
> +     * version has only one, so we must decide which one to pass. */
> +    if (blk_by_name(device)) {
> +        throttle.has_device = true;
> +        throttle.device = device;
> +    } else {
> +        throttle.has_id = true;
> +        throttle.id = device;
> +    }
> +
> +    qmp_block_set_io_throttle(&throttle, &err);
> +    hmp_handle_error(mon, err);
> +}
> +
> +void hmp_eject(Monitor *mon, const QDict *qdict)
> +{
> +    bool force = qdict_get_try_bool(qdict, "force", false);
> +    const char *device = qdict_get_str(qdict, "device");
> +    Error *err = NULL;
> +
> +    qmp_eject(true, device, false, NULL, true, force, &err);
> +    hmp_handle_error(mon, err);
> +}
> +
> +void hmp_qemu_io(Monitor *mon, const QDict *qdict)
> +{
> +    BlockBackend *blk;
> +    BlockBackend *local_blk = NULL;
> +    bool qdev = qdict_get_try_bool(qdict, "qdev", false);
> +    const char* device = qdict_get_str(qdict, "device");
> +    const char* command = qdict_get_str(qdict, "command");
> +    Error *err = NULL;
> +    int ret;
> +
> +    if (qdev) {
> +        blk = blk_by_qdev_id(device, &err);
> +        if (!blk) {
> +            goto fail;
> +        }
> +    } else {
> +        blk = blk_by_name(device);
> +        if (!blk) {
> +            BlockDriverState *bs = bdrv_lookup_bs(NULL, device, &err);
> +            if (bs) {
> +                blk = local_blk = blk_new(bdrv_get_aio_context(bs),
> +                                          0, BLK_PERM_ALL);
> +                ret = blk_insert_bs(blk, bs, &err);
> +                if (ret < 0) {
> +                    goto fail;
> +                }
> +            } else {
> +                goto fail;
> +            }
> +        }
> +    }
> +
> +    /*
> +     * Notably absent: Proper permission management. This is sad, but it seems
> +     * almost impossible to achieve without changing the semantics and thereby
> +     * limiting the use cases of the qemu-io HMP command.
> +     *
> +     * In an ideal world we would unconditionally create a new BlockBackend for
> +     * qemuio_command(), but we have commands like 'reopen' and want them to
> +     * take effect on the exact BlockBackend whose name the user passed instead
> +     * of just on a temporary copy of it.
> +     *
> +     * Another problem is that deleting the temporary BlockBackend involves
> +     * draining all requests on it first, but some qemu-iotests cases want to
> +     * issue multiple aio_read/write requests and expect them to complete in
> +     * the background while the monitor has already returned.
> +     *
> +     * This is also what prevents us from saving the original permissions and
> +     * restoring them later: We can't revoke permissions until all requests
> +     * have completed, and we don't know when that is nor can we really let
> +     * anything else run before we have revoken them to avoid race conditions.
> +     *
> +     * What happens now is that command() in qemu-io-cmds.c can extend the
> +     * permissions if necessary for the qemu-io command. And they simply stay
> +     * extended, possibly resulting in a read-only guest device keeping write
> +     * permissions. Ugly, but it appears to be the lesser evil.
> +     */
> +    qemuio_command(blk, command);
> +
> +fail:
> +    blk_unref(local_blk);
> +    hmp_handle_error(mon, err);
> +}
> diff --git a/include/block/block-hmp-commands.h b/include/block/block-hmp-commands.h
> index 721b9a1978..99145c8fcf 100644
> --- a/include/block/block-hmp-commands.h
> +++ b/include/block/block-hmp-commands.h
> @@ -26,4 +26,13 @@ void hmp_nbd_server_add(Monitor *mon, const QDict *qdict);
>  void hmp_nbd_server_remove(Monitor *mon, const QDict *qdict);
>  void hmp_nbd_server_stop(Monitor *mon, const QDict *qdict);
>  
> +void hmp_block_resize(Monitor *mon, const QDict *qdict);
> +void hmp_block_stream(Monitor *mon, const QDict *qdict);
> +void hmp_block_passwd(Monitor *mon, const QDict *qdict);
> +void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict);
> +void hmp_eject(Monitor *mon, const QDict *qdict);
> +
> +void hmp_qemu_io(Monitor *mon, const QDict *qdict);
> +
> +
>  #endif
> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
> index 736a969131..47a7cad734 100644
> --- a/include/monitor/hmp.h
> +++ b/include/monitor/hmp.h
> @@ -58,9 +58,7 @@ void hmp_cont(Monitor *mon, const QDict *qdict);
>  void hmp_system_wakeup(Monitor *mon, const QDict *qdict);
>  void hmp_nmi(Monitor *mon, const QDict *qdict);
>  void hmp_set_link(Monitor *mon, const QDict *qdict);
> -void hmp_block_passwd(Monitor *mon, const QDict *qdict);
>  void hmp_balloon(Monitor *mon, const QDict *qdict);
> -void hmp_block_resize(Monitor *mon, const QDict *qdict);
>  void hmp_loadvm(Monitor *mon, const QDict *qdict);
>  void hmp_savevm(Monitor *mon, const QDict *qdict);
>  void hmp_delvm(Monitor *mon, const QDict *qdict);
> @@ -80,10 +78,7 @@ void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict);
>  void hmp_x_colo_lost_heartbeat(Monitor *mon, const QDict *qdict);
>  void hmp_set_password(Monitor *mon, const QDict *qdict);
>  void hmp_expire_password(Monitor *mon, const QDict *qdict);
> -void hmp_eject(Monitor *mon, const QDict *qdict);
>  void hmp_change(Monitor *mon, const QDict *qdict);
> -void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict);
> -void hmp_block_stream(Monitor *mon, const QDict *qdict);
>  void hmp_migrate(Monitor *mon, const QDict *qdict);
>  void hmp_device_add(Monitor *mon, const QDict *qdict);
>  void hmp_device_del(Monitor *mon, const QDict *qdict);
> @@ -98,7 +93,6 @@ void hmp_chardev_add(Monitor *mon, const QDict *qdict);
>  void hmp_chardev_change(Monitor *mon, const QDict *qdict);
>  void hmp_chardev_remove(Monitor *mon, const QDict *qdict);
>  void hmp_chardev_send_break(Monitor *mon, const QDict *qdict);
> -void hmp_qemu_io(Monitor *mon, const QDict *qdict);
>  void hmp_cpu_add(Monitor *mon, const QDict *qdict);
>  void hmp_object_add(Monitor *mon, const QDict *qdict);
>  void hmp_object_del(Monitor *mon, const QDict *qdict);
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index 67d2ca8a4c..c224e0f338 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -46,7 +46,6 @@
>  #include "qom/object_interfaces.h"
>  #include "ui/console.h"
>  #include "block/qapi.h"
> -#include "qemu-io.h"
>  #include "qemu/cutils.h"
>  #include "qemu/error-report.h"
>  #include "exec/ramlist.h"
> @@ -1307,16 +1306,6 @@ void hmp_set_link(Monitor *mon, const QDict *qdict)
>      hmp_handle_error(mon, err);
>  }
>  
> -void hmp_block_passwd(Monitor *mon, const QDict *qdict)
> -{
> -    const char *device = qdict_get_str(qdict, "device");
> -    const char *password = qdict_get_str(qdict, "password");
> -    Error *err = NULL;
> -
> -    qmp_block_passwd(true, device, false, NULL, password, &err);
> -    hmp_handle_error(mon, err);
> -}
> -
>  void hmp_balloon(Monitor *mon, const QDict *qdict)
>  {
>      int64_t value = qdict_get_int(qdict, "value");
> @@ -1326,16 +1315,6 @@ void hmp_balloon(Monitor *mon, const QDict *qdict)
>      hmp_handle_error(mon, err);
>  }
>  
> -void hmp_block_resize(Monitor *mon, const QDict *qdict)
> -{
> -    const char *device = qdict_get_str(qdict, "device");
> -    int64_t size = qdict_get_int(qdict, "size");
> -    Error *err = NULL;
> -
> -    qmp_block_resize(true, device, false, NULL, size, &err);
> -    hmp_handle_error(mon, err);
> -}
> -
>  void hmp_loadvm(Monitor *mon, const QDict *qdict)
>  {
>      int saved_vm_running  = runstate_is_running();
> @@ -1818,15 +1797,6 @@ void hmp_expire_password(Monitor *mon, const QDict *qdict)
>      hmp_handle_error(mon, err);
>  }
>  
> -void hmp_eject(Monitor *mon, const QDict *qdict)
> -{
> -    bool force = qdict_get_try_bool(qdict, "force", false);
> -    const char *device = qdict_get_str(qdict, "device");
> -    Error *err = NULL;
> -
> -    qmp_eject(true, device, false, NULL, true, force, &err);
> -    hmp_handle_error(mon, err);
> -}
>  
>  #ifdef CONFIG_VNC
>  static void hmp_change_read_arg(void *opaque, const char *password,
> @@ -1884,49 +1854,6 @@ void hmp_change(Monitor *mon, const QDict *qdict)
>      hmp_handle_error(mon, err);
>  }
>  
> -void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict)
> -{
> -    Error *err = NULL;
> -    char *device = (char *) qdict_get_str(qdict, "device");
> -    BlockIOThrottle throttle = {
> -        .bps = qdict_get_int(qdict, "bps"),
> -        .bps_rd = qdict_get_int(qdict, "bps_rd"),
> -        .bps_wr = qdict_get_int(qdict, "bps_wr"),
> -        .iops = qdict_get_int(qdict, "iops"),
> -        .iops_rd = qdict_get_int(qdict, "iops_rd"),
> -        .iops_wr = qdict_get_int(qdict, "iops_wr"),
> -    };
> -
> -    /* qmp_block_set_io_throttle has separate parameters for the
> -     * (deprecated) block device name and the qdev ID but the HMP
> -     * version has only one, so we must decide which one to pass. */
> -    if (blk_by_name(device)) {
> -        throttle.has_device = true;
> -        throttle.device = device;
> -    } else {
> -        throttle.has_id = true;
> -        throttle.id = device;
> -    }
> -
> -    qmp_block_set_io_throttle(&throttle, &err);
> -    hmp_handle_error(mon, err);
> -}
> -
> -void hmp_block_stream(Monitor *mon, const QDict *qdict)
> -{
> -    Error *error = NULL;
> -    const char *device = qdict_get_str(qdict, "device");
> -    const char *base = qdict_get_try_str(qdict, "base");
> -    int64_t speed = qdict_get_try_int(qdict, "speed", 0);
> -
> -    qmp_block_stream(true, device, device, base != NULL, base, false, NULL,
> -                     false, NULL, qdict_haskey(qdict, "speed"), speed, true,
> -                     BLOCKDEV_ON_ERROR_REPORT, false, false, false, false,
> -                     &error);
> -
> -    hmp_handle_error(mon, error);
> -}
> -
>  typedef struct HMPMigrationStatus
>  {
>      QEMUTimer *timer;
> @@ -2219,70 +2146,6 @@ void hmp_chardev_send_break(Monitor *mon, const QDict *qdict)
>      hmp_handle_error(mon, local_err);
>  }
>  
> -void hmp_qemu_io(Monitor *mon, const QDict *qdict)
> -{
> -    BlockBackend *blk;
> -    BlockBackend *local_blk = NULL;
> -    bool qdev = qdict_get_try_bool(qdict, "qdev", false);
> -    const char* device = qdict_get_str(qdict, "device");
> -    const char* command = qdict_get_str(qdict, "command");
> -    Error *err = NULL;
> -    int ret;
> -
> -    if (qdev) {
> -        blk = blk_by_qdev_id(device, &err);
> -        if (!blk) {
> -            goto fail;
> -        }
> -    } else {
> -        blk = blk_by_name(device);
> -        if (!blk) {
> -            BlockDriverState *bs = bdrv_lookup_bs(NULL, device, &err);
> -            if (bs) {
> -                blk = local_blk = blk_new(bdrv_get_aio_context(bs),
> -                                          0, BLK_PERM_ALL);
> -                ret = blk_insert_bs(blk, bs, &err);
> -                if (ret < 0) {
> -                    goto fail;
> -                }
> -            } else {
> -                goto fail;
> -            }
> -        }
> -    }
> -
> -    /*
> -     * Notably absent: Proper permission management. This is sad, but it seems
> -     * almost impossible to achieve without changing the semantics and thereby
> -     * limiting the use cases of the qemu-io HMP command.
> -     *
> -     * In an ideal world we would unconditionally create a new BlockBackend for
> -     * qemuio_command(), but we have commands like 'reopen' and want them to
> -     * take effect on the exact BlockBackend whose name the user passed instead
> -     * of just on a temporary copy of it.
> -     *
> -     * Another problem is that deleting the temporary BlockBackend involves
> -     * draining all requests on it first, but some qemu-iotests cases want to
> -     * issue multiple aio_read/write requests and expect them to complete in
> -     * the background while the monitor has already returned.
> -     *
> -     * This is also what prevents us from saving the original permissions and
> -     * restoring them later: We can't revoke permissions until all requests
> -     * have completed, and we don't know when that is nor can we really let
> -     * anything else run before we have revoken them to avoid race conditions.
> -     *
> -     * What happens now is that command() in qemu-io-cmds.c can extend the
> -     * permissions if necessary for the qemu-io command. And they simply stay
> -     * extended, possibly resulting in a read-only guest device keeping write
> -     * permissions. Ugly, but it appears to be the lesser evil.
> -     */
> -    qemuio_command(blk, command);
> -
> -fail:
> -    blk_unref(local_blk);
> -    hmp_handle_error(mon, err);
> -}
> -
>  void hmp_object_del(Monitor *mon, const QDict *qdict)
>  {
>      const char *id = qdict_get_str(qdict, "id");
> -- 
> 2.17.2
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK