Re: [PATCH 1/5] block: update error message for bio_check_ro()

From: Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>
To: Minwoo Im <minwoo.im.dev@gmail.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
	"bvanassche@acm.org" <bvanassche@acm.org>,
	"axboe@kernel.dk" <axboe@kernel.dk>
Subject: Re: [PATCH 1/5] block: update error message for bio_check_ro()
Date: Wed, 3 Jul 2019 02:24:36 +0000	[thread overview]
Message-ID: <DM6PR04MB57548A80980931468D63D61386FB0@DM6PR04MB5754.namprd04.prod.outlook.com> (raw)
In-Reply-To: 20190703004240.GA19081@minwoo-desktop

On 7/2/19 5:42 PM, Minwoo Im wrote:
> On 19-07-01 14:57:22, Chaitanya Kulkarni wrote:
>> The existing code in the bio_check_ro() relies on the op_is_write().
>> op_is_write() checks for the last bit in the bio_op(). Now that we have
>> multiple REQ_OP_XXX with last bit set to 1 such as, (from blk_types.h):
>>
>> 	/* write sectors to the device */
>> 	REQ_OP_WRITE		= 1,
>> 	/* flush the volatile write cache */
>> 	REQ_OP_DISCARD		= 3,
>> 	/* securely erase sectors */
>> 	REQ_OP_SECURE_ERASE	= 5,
>> 	/* write the same sector many times */
>> 	REQ_OP_WRITE_SAME	= 7,
>> 	/* write the zero filled sector many times */
>> 	REQ_OP_WRITE_ZEROES	= 9,
>>
>> it is hard to understand which bio op failed in the bio_check_ro().
>>
>> Modify the error message in bio_check_ro() to print correct REQ_OP_XXX
>> with the help of blk_op_str().
>>
>> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>> ---
>>  block/blk-core.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/block/blk-core.c b/block/blk-core.c
>> index 5d1fc8e17dd1..47c8b9c48a57 100644
>> --- a/block/blk-core.c
>> +++ b/block/blk-core.c
>> @@ -786,9 +786,9 @@ static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
>>  			return false;
>>  
>>  		WARN_ONCE(1,
>> -		       "generic_make_request: Trying to write "
>> -			"to read-only block-device %s (partno %d)\n",
>> -			bio_devname(bio, b), part->partno);
>> +			"generic_make_request: Trying op %s on the "
>> +			"read-only block-device %s (partno %d)\n",
>> +			blk_op_str(op), bio_devname(bio, b), part->partno);
> Maybe "s/Trying op %s on/Tyring op %s to" just like the previous one?
> Not a native speaker, though ;)

Yeah, can be done at the time of applying patch if Jens is okay with it.

Otherwise I'll send V2.

>
> I think it would be better to see the log which holds the exact request
> operation type in a string.
>
> Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
>