Re: [Qemu-devel] [PATCH 10/10] qapi: Convert block_set_io_throttle

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 13 Jan 2012 14:53:19 -0600
Anthony Liguori <anthony@codemonkey.ws> wrote:

> On 01/09/2012 05:24 AM, Luiz Capitulino wrote:
> > Signed-off-by: Luiz Capitulino<lcapitulino@redhat.com>
> > ---
> >   blockdev.c       |   47 ++++++++++++++---------------------------------
> >   blockdev.h       |    2 --
> >   hmp-commands.hx  |    3 +--
> >   hmp.c            |   14 ++++++++++++++
> >   hmp.h            |    1 +
> >   qapi-schema.json |   29 +++++++++++++++++++++++++++++
> >   qmp-commands.hx  |    5 +----
> >   7 files changed, 60 insertions(+), 41 deletions(-)
> >
> > diff --git a/blockdev.c b/blockdev.c
> > index 8df78ce..5d16137 100644
> > --- a/blockdev.c
> > +++ b/blockdev.c
> > @@ -775,46 +775,29 @@ void qmp_change_blockdev(const char *device, const char *filename,
> >   }
> >
> >   /* throttling disk I/O limits */
> > -int do_block_set_io_throttle(Monitor *mon,
> > -                       const QDict *qdict, QObject **ret_data)
> > +void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
> > +                               int64_t bps_wr, int64_t iops, int64_t iops_rd,
> > +                               int64_t iops_wr, Error **errp)
> >   {
> >       BlockIOLimit io_limits;
> > -    const char *devname = qdict_get_str(qdict, "device");
> >       BlockDriverState *bs;
> >
> > -    io_limits.bps[BLOCK_IO_LIMIT_TOTAL]
> > -                        = qdict_get_try_int(qdict, "bps", -1);
> > -    io_limits.bps[BLOCK_IO_LIMIT_READ]
> > -                        = qdict_get_try_int(qdict, "bps_rd", -1);
> > -    io_limits.bps[BLOCK_IO_LIMIT_WRITE]
> > -                        = qdict_get_try_int(qdict, "bps_wr", -1);
> > -    io_limits.iops[BLOCK_IO_LIMIT_TOTAL]
> > -                        = qdict_get_try_int(qdict, "iops", -1);
> > -    io_limits.iops[BLOCK_IO_LIMIT_READ]
> > -                        = qdict_get_try_int(qdict, "iops_rd", -1);
> > -    io_limits.iops[BLOCK_IO_LIMIT_WRITE]
> > -                        = qdict_get_try_int(qdict, "iops_wr", -1);
> > -
> > -    bs = bdrv_find(devname);
> > +    bs = bdrv_find(device);
> >       if (!bs) {
> > -        qerror_report(QERR_DEVICE_NOT_FOUND, devname);
> > -        return -1;
> > +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
> > +        return;
> >       }
> >
> > -    if ((io_limits.bps[BLOCK_IO_LIMIT_TOTAL] == -1)
> > -        || (io_limits.bps[BLOCK_IO_LIMIT_READ] == -1)
> > -        || (io_limits.bps[BLOCK_IO_LIMIT_WRITE] == -1)
> > -        || (io_limits.iops[BLOCK_IO_LIMIT_TOTAL] == -1)
> > -        || (io_limits.iops[BLOCK_IO_LIMIT_READ] == -1)
> > -        || (io_limits.iops[BLOCK_IO_LIMIT_WRITE] == -1)) {
> > -        qerror_report(QERR_MISSING_PARAMETER,
> > -                      "bps/bps_rd/bps_wr/iops/iops_rd/iops_wr");
> > -        return -1;
> > -    }
> > +    io_limits.bps[BLOCK_IO_LIMIT_TOTAL] = bps;
> > +    io_limits.bps[BLOCK_IO_LIMIT_READ]  = bps_rd;
> > +    io_limits.bps[BLOCK_IO_LIMIT_WRITE] = bps_wr;
> > +    io_limits.iops[BLOCK_IO_LIMIT_TOTAL]= iops;
> > +    io_limits.iops[BLOCK_IO_LIMIT_READ] = iops_rd;
> > +    io_limits.iops[BLOCK_IO_LIMIT_WRITE]= iops_wr;
> >
> >       if (!do_check_io_limits(&io_limits)) {
> > -        qerror_report(QERR_INVALID_PARAMETER_COMBINATION);
> > -        return -1;
> > +        error_set(errp, QERR_INVALID_PARAMETER_COMBINATION);
> > +        return;
> >       }
> >
> >       bs->io_limits = io_limits;
> > @@ -829,8 +812,6 @@ int do_block_set_io_throttle(Monitor *mon,
> >               qemu_mod_timer(bs->block_timer, qemu_get_clock_ns(vm_clock));
> >           }
> >       }
> > -
> > -    return 0;
> >   }
> >
> >   int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
> > diff --git a/blockdev.h b/blockdev.h
> > index b077449..260e16b 100644
> > --- a/blockdev.h
> > +++ b/blockdev.h
> > @@ -62,6 +62,4 @@ void qmp_change_blockdev(const char *device, const char *filename,
> >                            bool has_format, const char *format, Error **errp);
> >   void do_commit(Monitor *mon, const QDict *qdict);
> >   int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
> > -int do_block_set_io_throttle(Monitor *mon,
> > -                             const QDict *qdict, QObject **ret_data);
> >   #endif
> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > index 9f44690..a5d8d33 100644
> > --- a/hmp-commands.hx
> > +++ b/hmp-commands.hx
> > @@ -1204,8 +1204,7 @@ ETEXI
> >           .args_type  = "device:B,bps:l,bps_rd:l,bps_wr:l,iops:l,iops_rd:l,iops_wr:l",
> >           .params     = "device bps bps_rd bps_wr iops iops_rd iops_wr",
> >           .help       = "change I/O throttle limits for a block drive",
> > -        .user_print = monitor_user_noop,
> > -        .mhandler.cmd_new = do_block_set_io_throttle,
> > +        .mhandler.cmd = hmp_block_set_io_throttle,
> >       },
> >
> >   STEXI
> > diff --git a/hmp.c b/hmp.c
> > index 89fa8e7..c88c93e 100644
> > --- a/hmp.c
> > +++ b/hmp.c
> > @@ -767,3 +767,17 @@ 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;
> > +
> > +    qmp_block_set_io_throttle(qdict_get_str(qdict, "device"),
> > +                              qdict_get_int(qdict, "bps"),
> > +                              qdict_get_int(qdict, "bps_rd"),
> > +                              qdict_get_int(qdict, "bps_wr"),
> > +                              qdict_get_int(qdict, "iops"),
> > +                              qdict_get_int(qdict, "iops_rd"),
> > +                              qdict_get_int(qdict, "iops_wr"),&err);
> > +    hmp_handle_error(mon,&err);
> > +}
> > diff --git a/hmp.h b/hmp.h
> > index 621bdc2..aab0b1f 100644
> > --- a/hmp.h
> > +++ b/hmp.h
> > @@ -53,5 +53,6 @@ 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);
> >
> >   #endif
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 36fd156..1e1f128 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -1403,3 +1403,32 @@
> >   ##
> >   { 'command': 'change',
> >     'data': {'device': 'str', 'target': 'str', '*arg': 'str'} }
> > +
> > +##
> > +# @block_set_io_throttle:
> > +#
> > +# Change I/O throttle limits for a block drive.
> > +#
> > +# @device: The name of the device
> > +#
> > +# @bps: total throughput limit in bytes per second
> > +#
> > +# @bps_rd: read throughput limit in bytes per second
> > +#
> > +# @bps_wr: read throughput limit in bytes per second
> 
> write throughput.

Fixed.

> > +#
> > +# @iops: total I/O operations per second
> > +#
> > +# @ops_rd: read I/O operations per second
> > +#
> > +# @iops_wr: write I/O operations per second
> > +#
> > +# Returns: Nothing on success
> > +#          If @device is not a valid block device, DeviceNotFound
> > +#          If the argument combination is invalid, InvalidParameterCombination
> > +#
> > +# Since: 1.1
> 
> 
> Do all of these fields have to be specified?  It looks like they were all 
> optional in the previous form of the command so they should probably be optional 
> here too.

They were required, as it's necessary to use '?' for optionals in the
args_type entry:

> > --- a/qmp-commands.hx
> > +++ b/qmp-commands.hx
> > @@ -807,10 +807,7 @@ EQMP
> >       {
> >           .name       = "block_set_io_throttle",
> >           .args_type  = "device:B,bps:l,bps_rd:l,bps_wr:l,iops:l,iops_rd:l,iops_wr:l",

The implementation also seems to imply they are required because there's
an explicit check for it (which can be dropped in the new version...).

Can the author/block guys confirm these parameters are intended to be
required?