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Date:   Fri, 18 Feb 2022 23:31:53 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Lu Baolu <baolu.lu@linux.intel.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Joerg Roedel <joro@8bytes.org>,
        Alex Williamson <alex.williamson@redhat.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Christoph Hellwig <hch@infradead.org>,
        Kevin Tian <kevin.tian@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, kvm@vger.kernel.org,
        rafael@kernel.org, David Airlie <airlied@linux.ie>,
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        Thierry Reding <thierry.reding@gmail.com>,
        Diana Craciun <diana.craciun@oss.nxp.com>,
        Dmitry Osipenko <digetx@gmail.com>,
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        Stuart Yoder <stuyoder@gmail.com>,
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        linux-kernel@vger.kernel.org, Li Yang <leoyang.li@nxp.com>,
        iommu@lists.linux-foundation.org,
        Jacob jun Pan <jacob.jun.pan@intel.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH v6 01/11] iommu: Add dma ownership management interfaces
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The overall API and patch looks fine, but:

> + * iommu_group_dma_owner_claimed() - Query group dma ownership status
> + * @group: The group.
> + *
> + * This provides status query on a given group. It is racey and only for
> + * non-binding status reporting.

s/racey/racy/

> + */
> +bool iommu_group_dma_owner_claimed(struct iommu_group *group)
> +{
> +	unsigned int user;
> +
> +	mutex_lock(&group->mutex);
> +	user = group->owner_cnt;
> +	mutex_unlock(&group->mutex);
> +
> +	return user;
> +}
> +EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);

Still no no need for the lock here.