Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <2a45f1e1-39d5-76b3-8fd3-c1f8b288afac@quicinc.com>
Date:   Fri, 13 May 2022 15:48:23 +0530
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.7.0
Subject: Re: [PATCH V3] dma-buf: ensure unique directory name for dmabuf stats
Content-Language: en-US
To:     Greg KH <gregkh@linuxfoundation.org>
CC:     <christian.koenig@amd.com>, <sumit.semwal@linaro.org>,
        <hridya@google.com>, <daniel.vetter@ffwll.ch>,
        <tjmercier@google.com>, <linux-media@vger.kernel.org>,
        <dri-devel@lists.freedesktop.org>,
        <linaro-mm-sig@lists.linaro.org>, <linux-kernel@vger.kernel.org>
References: <1652434689-6203-1-git-send-email-quic_charante@quicinc.com>
 <Yn4u0AG8iC33S3jO@kroah.com>
From:   Charan Teja Kalla <quic_charante@quicinc.com>
In-Reply-To: <Yn4u0AG8iC33S3jO@kroah.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 5/13/2022 3:41 PM, Greg KH wrote:
>> Reported-by: kernel test robot <lkp@intel.com>
> The trest robot did not say that the dmabuf stat name was being
> duplicated, did it?
>

It reported a printk warning on V2[1]. Should we remove this on V3?

@Christian: Could you please drop this tag while merging?

[1] https://lore.kernel.org/all/202205110511.E0d8TXXC-lkp@intel.com/


>> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
>> index a6fc96e..0ad5039 100644
>> --- a/drivers/dma-buf/dma-buf.c
>> +++ b/drivers/dma-buf/dma-buf.c
>> @@ -407,6 +407,7 @@ static inline int is_dma_buf_file(struct file *file)
>>  
>>  static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
>>  {
>> +	static atomic64_t dmabuf_inode = ATOMIC64_INIT(0);
>>  	struct file *file;
>>  	struct inode *inode = alloc_anon_inode(dma_buf_mnt->mnt_sb);
>>  
>> @@ -416,6 +417,13 @@ static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
>>  	inode->i_size = dmabuf->size;
>>  	inode_set_bytes(inode, dmabuf->size);
>>  
>> +	/*
>> +	 * The ->i_ino acquired from get_next_ino() is not unique thus
>> +	 * not suitable for using it as dentry name by dmabuf stats.
>> +	 * Override ->i_ino with the unique and dmabuffs specific
>> +	 * value.
>> +	 */
>> +	inode->i_ino = atomic64_add_return(1, &dmabuf_inode);
>>  	file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf",
>>  				 flags, &dma_buf_fops);
>>  	if (IS_ERR(file))
>> -- 
>> 2.7.4
>>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks for the ACK.

--Charan