| Message ID | 1471418115-3654-10-git-send-email-famz@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Aug 17, 2016 at 03:15:09PM +0800, Fam Zheng wrote: > Previously after device_add_disk returns, the KOBJ_ADD uevent is already > emitted. Adding attributes after that is a poor usage of kobject, and > in practice may result in race conditions with userspace, for > example udev checks availability of certain attributes and initializes > /dev entries conditionally. > > device_add_disk can handle adding attribute group better, so use it. > > Meanwhile, handle error of device_add_disk. > > Signed-off-by: Fam Zheng <famz@redhat.com> Feel free to merge this with the rest of patchset Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/block/virtio_blk.c | 38 +++++++++++++++++++++++++++----------- > 1 file changed, 27 insertions(+), 11 deletions(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 4564df5..ff60d82 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -522,10 +522,10 @@ virtblk_cache_type_show(struct device *dev, struct device_attribute *attr, > return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]); > } > > -static const struct device_attribute dev_attr_cache_type_ro = > +static struct device_attribute dev_attr_cache_type_ro = > __ATTR(cache_type, S_IRUGO, > virtblk_cache_type_show, NULL); > -static const struct device_attribute dev_attr_cache_type_rw = > +static struct device_attribute dev_attr_cache_type_rw = > __ATTR(cache_type, S_IRUGO|S_IWUSR, > virtblk_cache_type_show, virtblk_cache_type_store); > > @@ -550,6 +550,26 @@ static struct blk_mq_ops virtio_mq_ops = { > static unsigned int virtblk_queue_depth; > module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); > > +static struct attribute *virtblk_attrs_ro[] = { > + &dev_attr_serial.attr, > + &dev_attr_cache_type_ro.attr, > + NULL > +}; > + > +static struct attribute *virtblk_attrs_rw[] = { > + &dev_attr_serial.attr, > + &dev_attr_cache_type_rw.attr, > + NULL > +}; > + > +static struct attribute_group virtblk_attr_group_ro = { > + .attrs = virtblk_attrs_ro, > +}; > + > +static struct attribute_group virtblk_attr_group_rw = { > + .attrs = virtblk_attrs_rw, > +}; > + > static int virtblk_probe(struct virtio_device *vdev) > { > struct virtio_blk *vblk; > @@ -560,6 +580,7 @@ static int virtblk_probe(struct virtio_device *vdev) > u32 v, blk_size, sg_elems, opt_io_size; > u16 min_io_size; > u8 physical_block_exp, alignment_offset; > + struct attribute_group *attr_group; > > if (!vdev->config->get) { > dev_err(&vdev->dev, "%s failure: config access disabled\n", > @@ -719,19 +740,14 @@ static int virtblk_probe(struct virtio_device *vdev) > > virtio_device_ready(vdev); > > - device_add_disk(&vdev->dev, vblk->disk, NULL); > - err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial); > - if (err) > - goto out_del_disk; > - > if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) > - err = device_create_file(disk_to_dev(vblk->disk), > - &dev_attr_cache_type_rw); > + attr_group = &virtblk_attr_group_rw; > else > - err = device_create_file(disk_to_dev(vblk->disk), > - &dev_attr_cache_type_ro); > + attr_group = &virtblk_attr_group_ro; > + err = device_add_disk(&vdev->dev, vblk->disk, attr_group); > if (err) > goto out_del_disk; > + > return 0; > > out_del_disk: > -- > 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 4564df5..ff60d82 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -522,10 +522,10 @@ virtblk_cache_type_show(struct device *dev, struct device_attribute *attr, return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]); } -static const struct device_attribute dev_attr_cache_type_ro = +static struct device_attribute dev_attr_cache_type_ro = __ATTR(cache_type, S_IRUGO, virtblk_cache_type_show, NULL); -static const struct device_attribute dev_attr_cache_type_rw = +static struct device_attribute dev_attr_cache_type_rw = __ATTR(cache_type, S_IRUGO|S_IWUSR, virtblk_cache_type_show, virtblk_cache_type_store); @@ -550,6 +550,26 @@ static struct blk_mq_ops virtio_mq_ops = { static unsigned int virtblk_queue_depth; module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); +static struct attribute *virtblk_attrs_ro[] = { + &dev_attr_serial.attr, + &dev_attr_cache_type_ro.attr, + NULL +}; + +static struct attribute *virtblk_attrs_rw[] = { + &dev_attr_serial.attr, + &dev_attr_cache_type_rw.attr, + NULL +}; + +static struct attribute_group virtblk_attr_group_ro = { + .attrs = virtblk_attrs_ro, +}; + +static struct attribute_group virtblk_attr_group_rw = { + .attrs = virtblk_attrs_rw, +}; + static int virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; @@ -560,6 +580,7 @@ static int virtblk_probe(struct virtio_device *vdev) u32 v, blk_size, sg_elems, opt_io_size; u16 min_io_size; u8 physical_block_exp, alignment_offset; + struct attribute_group *attr_group; if (!vdev->config->get) { dev_err(&vdev->dev, "%s failure: config access disabled\n", @@ -719,19 +740,14 @@ static int virtblk_probe(struct virtio_device *vdev) virtio_device_ready(vdev); - device_add_disk(&vdev->dev, vblk->disk, NULL); - err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial); - if (err) - goto out_del_disk; - if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) - err = device_create_file(disk_to_dev(vblk->disk), - &dev_attr_cache_type_rw); + attr_group = &virtblk_attr_group_rw; else - err = device_create_file(disk_to_dev(vblk->disk), - &dev_attr_cache_type_ro); + attr_group = &virtblk_attr_group_ro; + err = device_add_disk(&vdev->dev, vblk->disk, attr_group); if (err) goto out_del_disk; + return 0; out_del_disk:
Previously after device_add_disk returns, the KOBJ_ADD uevent is already emitted. Adding attributes after that is a poor usage of kobject, and in practice may result in race conditions with userspace, for example udev checks availability of certain attributes and initializes /dev entries conditionally. device_add_disk can handle adding attribute group better, so use it. Meanwhile, handle error of device_add_disk. Signed-off-by: Fam Zheng <famz@redhat.com> --- drivers/block/virtio_blk.c | 38 +++++++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 11 deletions(-)