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From:   John Ogness <john.ogness@linutronix.de>
To:     Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc:     Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marco Elver <elver@google.com>, kexec@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH][next] printk: ringbuffer: support dataless records
In-Reply-To: <20200721025450.GA5678@jagdpanzerIV.localdomain>
References: <20200720140111.19935-1-john.ogness@linutronix.de> <20200721025450.GA5678@jagdpanzerIV.localdomain>
Date:   Tue, 21 Jul 2020 12:36:55 +0206
Message-ID: <87lfjdw468.fsf@jogness.linutronix.de>
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Sender: linux-kernel-owner@vger.kernel.org
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On 2020-07-21, Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
>> @@ -1402,7 +1396,9 @@ static int prb_read(struct printk_ringbuffer *rb, u64 seq,
>>  	/* Copy text data. If it fails, this is a data-less record. */
>>  	if (!copy_data(&rb->text_data_ring, &desc.text_blk_lpos, desc.info.text_len,
>>  		       r->text_buf, r->text_buf_size, line_count)) {
>> -		return -ENOENT;
>> +		/* Report an error if there should have been data. */
>> +		if (desc.info.text_len != 0)
>> +			return -ENOENT;
>>  	}
>
> If this is a dataless record then should copy_data() return error?

You are correct. That makes more sense. I will send a v2.

John Ogness