Re: [PATCH v10 7/8] xfs: Validate atomic writes

[John Garry <john.g.garry@oracle.com>]

On 20/10/2024 10:44, Ritesh Harjani (IBM) wrote:
>> +	if (iocb->ki_flags & IOCB_ATOMIC) {
>> +		/*
>> +		 * Currently only atomic writing of a single FS block is
>> +		 * supported. It would be possible to atomic write smaller than
>> +		 * a FS block, but there is no requirement to support this.
>> +		 * Note that iomap also does not support this yet.
>> +		 */
>> +		if (ocount != ip->i_mount->m_sb.sb_blocksize)
>> +			return -EINVAL;
> Shouldn't we "return -ENOTSUPP" ?
> Given we are later going to add support for ocount > sb_blocksize.

So far we have been reporting -EINVAL for an invalid atomic write size 
(according to atomic write unit min and max reported for that inode).

-ENOTSUPP is used for times when we just don't support atomic writes, 
like non-DIO.

Thanks,
John