Re: [PATCH V5] mtd: ubi: Extend UBI layer debug/messaging capabilities

[Tanya Brokhman <tlinder@codeaurora.org>]

On 10/24/2014 6:33 AM, hujianyang wrote:
> Hi Tanya,
>
> When I was trying to push this patch to my product, I reviewed this patch
> and found some small problems. I wish it's not too late to report these.
>
> The patch I get from linux-ubifs.git is amended a bit by Artem. I'd like to
> quote your V5 patch for simplification. Some line numbers may mismatching.
>
>> @@ -1408,20 +1416,20 @@ static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
>>   		return -EINVAL;
>>
>>   	if (mtd_devs == UBI_MAX_DEVICES) {
>> -		ubi_err("too many parameters, max. is %d\n",
>> +		pr_err("UBI error: too many parameters, max. is %d\n",
>>   			UBI_MAX_DEVICES);
>>   		return -EINVAL;
>>   	}
>>
>>   	len = strnlen(val, MTD_PARAM_LEN_MAX);
>>   	if (len == MTD_PARAM_LEN_MAX) {
>> -		ubi_err("parameter \"%s\" is too long, max. is %d\n",
>> +		pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
>>   			val, MTD_PARAM_LEN_MAX);
>>   		return -EINVAL;
>>   	}
>>
>>   	if (len == 0) {
>> -		pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
>> +		pr_err("UBI warning: empty 'mtd=' parameter - ignored\n");
>>   		return 0;
>>   	}
>
> Why the last 'pr_warn()' need to be changed into 'pr_err()'? I looked up your
> V1 and V2 patches, I think it's not your purpose.

It slipped somehow. Thanks! fixed.

>
>
>
>> @@ -176,6 +176,7 @@ static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
>>
>>   /**
>>    * validate_vid_hdr - check volume identifier header.
>> + * @ubi: UBI device description object
>>    * @vid_hdr: the volume identifier header to check
>>    * @av: information about the volume this logical eraseblock belongs to
>>    * @pnum: physical eraseblock number the VID header came from
>
>> @@ -48,13 +48,14 @@
>>
>>   /**
>>    * get_exclusive - get exclusive access to an UBI volume.
>> + * @ubi: UBI device description object
>>    * @desc: volume descriptor
>>    *
>>    * This function changes UBI volume open mode to "exclusive". Returns previous
>>    * mode value (positive integer) in case of success and a negative error code
>>    * in case of failure.
>>    */
>
>> @@ -660,13 +660,14 @@ static int init_volumes(struct ubi_device *ubi,
>>
>>   /**
>>    * check_av - check volume attaching information.
>> + * @ubi: UBI device description object
>>    * @vol: UBI volume description object
>>    * @av: volume attaching information
>>    *
>>    * This function returns zero if the volume attaching information is consistent
>>    * to the data read from the volume tabla, and %-EINVAL if not.
>>    */
>> -static int check_av(const struct ubi_volume *vol,
>> +static int check_av(const struct ubi_device *ubi, const struct ubi_volume *vol,
>>   		    const struct ubi_ainf_volume *av)
>>   {
>>   	int err;
>
> This patch add 'struct ubi_device *' for 3 functions. We can get 'ubi_device' from
> 'ubi_volume'. So I think it's because when we call these functions, the '->ubi'
> pointer of 'ubi_volume' is not initialized, am I right? This patch use 'vol->ubi'
> to indicate a 'struct ubi_device *' pointer in some places, I think you are sure
> of using them.
>

1. for validate_vid_hdr() we don;t have a ubi_volume yet since its part 
of the attach process so we need struct ubi_device
2. for get_exclusive() - you're right. Will fetch dev number from the volume
3. for check_av() - you're right. fixed

>
>
>> @@ -1010,28 +1015,28 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
>>   	ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
>>   	if (IS_ERR(ubi->bgt_thread)) {
>>   		err = PTR_ERR(ubi->bgt_thread);
>> -		ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
>> -			err);
>> +		ubi_err(ubi, "cannot spawn \"%s\", error %d",
>> +			ubi->bgt_name, err);
>>   		goto out_debugfs;
>>   	}
>>
>> -	ubi_msg("attached mtd%d (name \"%s\", size %llu MiB) to ubi%d",
>> -		mtd->index, mtd->name, ubi->flash_size >> 20, ubi_num);
>> -	ubi_msg("PEB size: %d bytes (%d KiB), LEB size: %d bytes",
>> +	ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
>> +		mtd->index, mtd->name, ubi->flash_size >> 20);
>> +	ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
>>   		ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
>
> We have the parameter 'ubi_num' for log in some functions like 'ubi_attach_mtd_dev'
> before. This patch remove 'ubi_num' in upper changes but keep it in other changes.
> Do we have a discussed rule to deal with this situation? It's not a big problem~

I removed it because it made no sense printing it twice:
"ubi-0: attached mtd-0 (...) to ubi0"?
so I shortned the message:
"ubi-0: attched mtd..."
All the info is still there....
Same for other messages that printed ubi number.

>
>
>
>> @@ -1798,15 +1803,18 @@ int ubi_thread(void *u)
>>   	int failures = 0;
>>   	struct ubi_device *ubi = u;
>>
>> -	ubi_msg("background thread \"%s\" started, PID %d",
>> +	ubi_msg(ubi, "background thread \"%s\" started, PID %d",
>>   		ubi->bgt_name, task_pid_nr(current));
>>
>>   	set_freezable();
>>   	for (;;) {
>>   		int err;
>>
>> -		if (kthread_should_stop())
>> +		if (kthread_should_stop()) {
>> +			ubi_msg(ubi, "background thread \"%s\" should stop, PID %d",
>> +				ubi->bgt_name, task_pid_nr(current));
>>   			break;
>> +		}
>>
>>   		if (try_to_freeze())
>>   			continue;
>
>> @@ -1798,15 +1803,18 @@ int ubi_thread(void *u)
>>   	int failures = 0;
>>   	struct ubi_device *ubi = u;
>>
>> -	ubi_msg("background thread \"%s\" started, PID %d",
>> +	ubi_msg(ubi, "background thread \"%s\" started, PID %d",
>>   		ubi->bgt_name, task_pid_nr(current));
>>
>>   	set_freezable();
>>   	for (;;) {
>>   		int err;
>>
>> -		if (kthread_should_stop())
>> +		if (kthread_should_stop()) {
>> +			ubi_msg(ubi, "background thread \"%s\" should stop, PID %d",
>> +				ubi->bgt_name, task_pid_nr(current));
>>   			break;
>> +		}
>>
>>   		if (try_to_freeze())
>>   			continue;
>
> Here are two new adding messages. Maybe a separate patch is better? Just a
> suggestion.

Done.

>
>
>> @@ -1415,8 +1418,9 @@ int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
>>   	return 0;
>>
>>   fail:
>> -	ubi_err("self-check failed for PEB %d", pnum);
>> -	ubi_msg("hex dump of the %d-%d region", offset, offset + len);
>> +	ubi_err(ubi, "self-check failed for PEB %d", pnum);
>> +	ubi_msg(ubi, "hex dump of the %d-%d region",
>> +		 offset, offset + len);
>>   	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
>>   	err = -EINVAL;
>>   error:
>
> Artem, I know you have tried to align the message code in different lines, maybe
> you can check if you lose this one.
>

hmmm... not sure I understand what is wrong here....

>
> Thanks~!
>
> Hu
>
>
>


Thanks,
Tanya Brokhman
-- 
Qualcomm Israel, on behalf of Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project