Re: [PATCH V3] dma-buf: ensure unique directory name for dmabuf stats

[Charan Teja Kalla <quic_charante@quicinc.com>]

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