Re: [PATCH v8 2/8] block: consolidate blocksize properties consistency checks

[Markus Armbruster <armbru@redhat.com>]

Roman Kagan <rvkagan@yandex-team.ru> writes:

> Several block device properties related to blocksize configuration must
> be in certain relationship WRT each other: physical block must be no
> smaller than logical block; min_io_size, opt_io_size, and
> discard_granularity must be a multiple of a logical block.
>
> To ensure these requirements are met, add corresponding consistency
> checks to blkconf_blocksizes, adjusting its signature to communicate
> possible error to the caller.  Also remove the now redundant consistency
> checks from the specific devices.
>
> Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Reviewed-by: Paul Durrant <paul@xen.org>
> ---
>  include/hw/block/block.h   |  2 +-
>  hw/block/block.c           | 30 +++++++++++++++++++++++++++++-
>  hw/block/fdc.c             |  5 ++++-
>  hw/block/nvme.c            |  5 ++++-
>  hw/block/swim.c            |  5 ++++-
>  hw/block/virtio-blk.c      |  7 +------
>  hw/block/xen-block.c       |  6 +-----
>  hw/ide/qdev.c              |  5 ++++-
>  hw/scsi/scsi-disk.c        | 12 +++++-------
>  hw/usb/dev-storage.c       |  5 ++++-
>  tests/qemu-iotests/172.out |  2 +-
>  11 files changed, 58 insertions(+), 26 deletions(-)
>
> diff --git a/include/hw/block/block.h b/include/hw/block/block.h
> index d7246f3862..784953a237 100644
> --- a/include/hw/block/block.h
> +++ b/include/hw/block/block.h
> @@ -87,7 +87,7 @@ bool blk_check_size_and_read_all(BlockBackend *blk, void *buf, hwaddr size,
>  bool blkconf_geometry(BlockConf *conf, int *trans,
>                        unsigned cyls_max, unsigned heads_max, unsigned secs_max,
>                        Error **errp);
> -void blkconf_blocksizes(BlockConf *conf);
> +bool blkconf_blocksizes(BlockConf *conf, Error **errp);
>  bool blkconf_apply_backend_options(BlockConf *conf, bool readonly,
>                                     bool resizable, Error **errp);
>  
> diff --git a/hw/block/block.c b/hw/block/block.c
> index bf56c7612b..b22207c921 100644
> --- a/hw/block/block.c
> +++ b/hw/block/block.c
> @@ -61,7 +61,7 @@ bool blk_check_size_and_read_all(BlockBackend *blk, void *buf, hwaddr size,
>      return true;
>  }
>  
> -void blkconf_blocksizes(BlockConf *conf)
> +bool blkconf_blocksizes(BlockConf *conf, Error **errp)
>  {
>      BlockBackend *blk = conf->blk;
>      BlockSizes blocksizes;
> @@ -83,6 +83,34 @@ void blkconf_blocksizes(BlockConf *conf)
>              conf->logical_block_size = BDRV_SECTOR_SIZE;
>          }
>      }
> +
> +    if (conf->logical_block_size > conf->physical_block_size) {
> +        error_setg(errp,
> +                   "logical_block_size > physical_block_size not supported");
> +        return false;
> +    }

Pardon me if this has been answered already for prior revisions: do we
really support physical block sizes that are not a multiple of the
logical block size?

> +
> +    if (!QEMU_IS_ALIGNED(conf->min_io_size, conf->logical_block_size)) {
> +        error_setg(errp,
> +                   "min_io_size must be a multiple of logical_block_size");
> +        return false;
> +    }
> +
> +    if (!QEMU_IS_ALIGNED(conf->opt_io_size, conf->logical_block_size)) {
> +        error_setg(errp,
> +                   "opt_io_size must be a multiple of logical_block_size");
> +        return false;
> +    }
> +
> +    if (conf->discard_granularity != -1 &&
> +        !QEMU_IS_ALIGNED(conf->discard_granularity,
> +                         conf->logical_block_size)) {
> +        error_setg(errp, "discard_granularity must be "
> +                   "a multiple of logical_block_size");
> +        return false;
> +    }
> +
> +    return true;
>  }
>  
>  bool blkconf_apply_backend_options(BlockConf *conf, bool readonly,
> diff --git a/hw/block/fdc.c b/hw/block/fdc.c
> index c5fb9d6ece..8eda572ef4 100644
> --- a/hw/block/fdc.c
> +++ b/hw/block/fdc.c
> @@ -554,7 +554,10 @@ static void floppy_drive_realize(DeviceState *qdev, Error **errp)
>          read_only = !blk_bs(dev->conf.blk) || blk_is_read_only(dev->conf.blk);
>      }
>  
> -    blkconf_blocksizes(&dev->conf);
> +    if (!blkconf_blocksizes(&dev->conf, errp)) {
> +        return;
> +    }
> +
>      if (dev->conf.logical_block_size != 512 ||
>          dev->conf.physical_block_size != 512)
>      {
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index 2f3100e56c..672650e162 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -1390,7 +1390,10 @@ static void nvme_realize(PCIDevice *pci_dev, Error **errp)
>          host_memory_backend_set_mapped(n->pmrdev, true);
>      }
>  
> -    blkconf_blocksizes(&n->conf);
> +    if (!blkconf_blocksizes(&n->conf, errp)) {
> +        return;
> +    }
> +
>      if (!blkconf_apply_backend_options(&n->conf, blk_is_read_only(n->conf.blk),
>                                         false, errp)) {
>          return;
> diff --git a/hw/block/swim.c b/hw/block/swim.c
> index 8f124782f4..74f56e8f46 100644
> --- a/hw/block/swim.c
> +++ b/hw/block/swim.c
> @@ -189,7 +189,10 @@ static void swim_drive_realize(DeviceState *qdev, Error **errp)
>          assert(ret == 0);
>      }
>  
> -    blkconf_blocksizes(&dev->conf);
> +    if (!blkconf_blocksizes(&dev->conf, errp)) {
> +        return;
> +    }
> +
>      if (dev->conf.logical_block_size != 512 ||
>          dev->conf.physical_block_size != 512)
>      {
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 413083e62f..4ffdb130be 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -1162,12 +1162,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
>          return;
>      }
>  
> -    blkconf_blocksizes(&conf->conf);
> -
> -    if (conf->conf.logical_block_size >
> -        conf->conf.physical_block_size) {
> -        error_setg(errp,
> -                   "logical_block_size > physical_block_size not supported");
> +    if (!blkconf_blocksizes(&conf->conf, errp)) {
>          return;
>      }
>  
> diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
> index 570489d6d9..e17fec50e1 100644
> --- a/hw/block/xen-block.c
> +++ b/hw/block/xen-block.c
> @@ -239,11 +239,7 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
>          return;
>      }
>  
> -    blkconf_blocksizes(conf);
> -
> -    if (conf->logical_block_size > conf->physical_block_size) {
> -        error_setg(
> -            errp, "logical_block_size > physical_block_size not supported");
> +    if (!blkconf_blocksizes(conf, errp)) {
>          return;
>      }
>  
> diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
> index 06b11583f5..b4821b2403 100644
> --- a/hw/ide/qdev.c
> +++ b/hw/ide/qdev.c
> @@ -187,7 +187,10 @@ static void ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind, Error **errp)
>          return;
>      }
>  
> -    blkconf_blocksizes(&dev->conf);
> +    if (!blkconf_blocksizes(&dev->conf, errp)) {
> +        return;
> +    }
> +
>      if (dev->conf.logical_block_size != 512) {
>          error_setg(errp, "logical_block_size must be 512 for IDE");
>          return;
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index 387503e11b..8ce68a9dd6 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -2346,12 +2346,7 @@ static void scsi_realize(SCSIDevice *dev, Error **errp)
>          return;
>      }
>  
> -    blkconf_blocksizes(&s->qdev.conf);
> -
> -    if (s->qdev.conf.logical_block_size >
> -        s->qdev.conf.physical_block_size) {
> -        error_setg(errp,
> -                   "logical_block_size > physical_block_size not supported");
> +    if (!blkconf_blocksizes(&s->qdev.conf, errp)) {
>          return;
>      }
>  
> @@ -2436,7 +2431,9 @@ static void scsi_hd_realize(SCSIDevice *dev, Error **errp)
>      if (s->qdev.conf.blk) {
>          ctx = blk_get_aio_context(s->qdev.conf.blk);
>          aio_context_acquire(ctx);
> -        blkconf_blocksizes(&s->qdev.conf);
> +        if (!blkconf_blocksizes(&s->qdev.conf, errp)) {
> +            goto out;
> +        }
>      }
>      s->qdev.blocksize = s->qdev.conf.logical_block_size;
>      s->qdev.type = TYPE_DISK;
> @@ -2444,6 +2441,7 @@ static void scsi_hd_realize(SCSIDevice *dev, Error **errp)
>          s->product = g_strdup("QEMU HARDDISK");
>      }
>      scsi_realize(&s->qdev, errp);
> +out:
>      if (ctx) {
>          aio_context_release(ctx);
>      }
> diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
> index 4eba47538d..de461f37bd 100644
> --- a/hw/usb/dev-storage.c
> +++ b/hw/usb/dev-storage.c
> @@ -599,7 +599,10 @@ static void usb_msd_storage_realize(USBDevice *dev, Error **errp)
>          return;
>      }
>  
> -    blkconf_blocksizes(&s->conf);
> +    if (!blkconf_blocksizes(&s->conf, errp)) {
> +        return;
> +    }
> +
>      if (!blkconf_apply_backend_options(&s->conf, blk_is_read_only(blk), true,
>                                         errp)) {
>          return;
> diff --git a/tests/qemu-iotests/172.out b/tests/qemu-iotests/172.out
> index 7abbe82427..59cc70aebb 100644
> --- a/tests/qemu-iotests/172.out
> +++ b/tests/qemu-iotests/172.out
> @@ -1204,7 +1204,7 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,physica
>                  drive-type = "144"
>  
>  Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,logical_block_size=4096
> -QEMU_PROG: -device floppy,drive=none0,logical_block_size=4096: Physical and logical block size must be 512 for floppy
> +QEMU_PROG: -device floppy,drive=none0,logical_block_size=4096: logical_block_size > physical_block_size not supported
>  
>  Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,physical_block_size=1024
>  QEMU_PROG: -device floppy,drive=none0,physical_block_size=1024: Physical and logical block size must be 512 for floppy

This no longer exercises floppy_drive_realize()'s check of
logical_block_size:

    if (dev->conf.logical_block_size != 512 ||
        dev->conf.physical_block_size != 512)
    {
        error_setg(errp, "Physical and logical block size must "
                   "be 512 for floppy");
        return;
    }

Please update the test.